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Spatial Daylight Autonomy Criteria

European Standard – prEn17037

Space Type Target daylight illuminance Minimum % of space to comply for target lx Minimum daylight illuminance Minimum % of space to comply for min lx
Spaces lit with windows 300 lx for more than half of the daylight hours in the year 50% 100 lx for more than half of the daylight hours in the year 95%
Spaces lit with rooflights 300 lx for more than half of the daylight hours in the year 95%

Notes

  • Daylight Hours: The hours of daylight are determined by rank-ordering (i.e. from highest to lowest) the 8 760 values for diffuse horizontal illuminance and then extracting the first (i.e. the highest) 4 380 hourly values.Note that the retained (i.e. highest) 4 380 values may include some zero values, or that the discarded 4 380 values may include some non-zero values.
    This is to be expected given the nature of illuminance data in climate files and does not affect the outcome.
  • The relevant area of the space plane covers the entire space, and is located 0.85m above the floor.
  • A perimeter area is excluded from the area of the space, because locally, illuminances are not relevant to the assessment of daylight provision, since the illuminances can be excessively high (near windows) or excessively low, next to opaque walls.A perimeter area is the area located next to the walls of the space, and should be excluded in daylight calculations.

BREEAM

Setting Weather Location and Hours

Setting up Weather data and location

Select location for climate based calculation on Project Settings dialogue.
All weather data files must be in epw format and located in below folder:

Autocad: %appdata%\MBS Software\Waldram Tools\Climate Files
Revit: %appdata%\MBS Software\Revit Waldram Tools\Climate Files

This setting is project specific and needs to be set per job.

  • Before running the calculation, the regulation and annual daylight hours has to be set through Settings dialogue.The test has to be run separately for each regulation. Results are saved per regulation and thus once they are calculated, corresponding reports could be outputted without a rerun.
  • The recommendation daylight hours for BREEAM and EN17037 is Sunrise to Sunset.
  • The filter hour is inclusive for the start hour and exclusive for the end hour.
    For example, if the occupancy starts at 9 AM and finishes at 5PM, the filter hour should be set to 9 to 17 (8 Hour Occupancy)

Setting Pass Criteria for calculations

Setting Criteria for Climate based Calculations

Assessment Criteria are set per project in Project Settings dialogue > Climate Assessment Criteria tab.

Setting SDA BREEAM Criteria

All the entries on BREEAM Regulations Table 5.3 are predefined based on the BREEAM New Construction 2018 and loaded as default in Criteria table dialogue.

 

Each property and room type pair in BREEAM Regulations Table 5.3 is translated into one or two rows(based on number of credits, target lux, occuppied hours) in the dialogue.
If a property, room type pair has different credits, target lux or occupied hours one row is added for each credit in the table dialogue.

The Selected column displays the criteria that are set for calculation. The SDA calculation uses the
registered property and space type of a room to query its assessment criteria from the above table. If more than
one records exists for this property and room type, the Selected is returned from the table. If no records exists
the default “Other Building Types” criterion is used.

As an example, below Staff room type in Healthcare property has two entries for 1 Credit and 2 Credit with different occupied hours.

Two records are added to the table with the corresponding values for credit value, target lux and occupied hours.
The first entry for credit 1 is selected for calculation.

– To Add new criterion fill in the text boxes with corresponding criterion and press the New Row button. Note that
the AreaToComply column takes value between 0 – 1.

– To Delete an existing criterion select the row on the table and press the Delete Selected Row button.

– To Update an existing criterion simply change the values on the table.

 

Setting SDA EN17037 Criteria

The criteria is set according to EN17037 Regulations. The criteria are fixed and grouped by their rating. The Selected criterion is queried and used for calculation.

Notes for All Climate Criteria

Note 1: The output report displays criteria that has been set prior to running the calculation. In other words the selected criteria record is saved against the room on calculation time and same criteria is queried at report time.

Note 2: Changing the Selected criteria, changes to Target Lux, Target Lux Min, Target Hours requires rerunning the calculation. “Area To Comply” and “Credit For Area To Comply” does not require rerun.

Steps to run Climate calculations

  • Put the objects in the model in specific layers. e.g. walls in “wall” layer, any external obstructions in “external” layer and so on. The registered windows will automatically get Glass material based on their ADF properties set during the registration time. For more details on how to setup the model for running Daylight Factor, utility commands that automate the process and questions on Window Glazing Transmittance please refer to How to Setup a model for Assigning the Material section.
  • Open the Material dialogue and assign a material for each layer. Material Library has a predefined list of most of the common materials. Yet you can define your own or customize them. For more details on how the material dialogue works please refer to Assign materials through material dialogue
  • Set the Ray tracing Method and its options on Settings > Ray tracing method
  • Set climate file
  • Set climate criteria
  • Set climate regulation to BREEAM, EN, EN BS or LEED
  • Convert to Radiance format and run the calculations.

Daylight Factor Definitions

Terms and Definitions

BREEAM 2018

Average Daylight Factor

The average daylight factor is the average indoor illuminance (from daylight) on the working plane within a room, expressed as a percentage of the simultaneous outdoor illuminance on a horizontal plane under an unobstructed CIE Standard Overcast Sky.

Point daylight factor

A point daylight factor is the ratio between the illuminance (from daylight) at a specific point on the working plane within a room, expressed as a percentage of the illuminance received on an outdoor unobstructed horizontal plane. The minimum point daylight factor is the lowest value of the daylight factor on the working plane at a point that is not within 0.5m of a wall.

Uniformity

The uniformity is the ratio between the minimum illuminance (from daylight) on the working plane within a room (or minimum daylight factor) and the average illuminance (from daylight) on the same working plane (or average daylight factor).

Daylight Factor Criteria

Daylight Factor Criteria

BREEAM 2018

The relevant building areas must meet

1. minimum value of average daylight factors required

2. Daylighting uniformity criteria

Stencil Daylight Factor Image

Radiance Stencil Daylight Factor Method

To generate stencil image from room polyline at working height:

1. Open MBS render dialogue by typing MBSRndr

2. Set the Raytracing method to Radiance in Settings > Ray tracing tab

3. Select Stencil DF in Render dialogue.

4. Set Image Quality to either Low, Medium, High. This type of rendering can take very long time on medium or high mode.

5. Click on Render button. It then asks to pick of the room polyline from the model. Press Enter or Right click after selecting the room and rendering starts.

 

Steps to run Daylight Factor calculation

  • Put the objects in the model in specific layers. e.g. walls in “wall” layer, any external obstructions in “external” layer and so on. The registered windows will automatically get Glass material based on their ADF properties set during the registration time.
    However the registered windows must be added to relevant classicgroup before conversion.  For more details on how to setup the model for running Daylight Factor, utility commands that automate the process and questions on Window Glazing Transmittance please refer to How to Setup a model for Assigning the Material section.
  • Open the Material dialogue and assign a material for each layer. Material Library has a predefined list of most of the common materials. Yet you can define your own or customize them. For more details on how the material dialogue works please refer to Assign materials through material dialogue
  • Set the Ray tracing Method and its options on Settings > Ray tracing method
  • [Optional] The Sky distribution used for Daylight Factor is CIE Overcast Sky. However this can be change to Uniform Sky on Project Settings dialogue > General tab
  • Convert to Radiance format and run the calculations.

Annual Potential Glare

Any specular material that reflects Sun beam directed towards the view point is detected
as glare source and is marked in colour banding on the image. The process to create the
image is as follows:

1. Set the location in Project Settings > General tab by selecting the weather file.

2. Assign Mirror material in Project Settings > Material dialogue to all surfaces
that are considered to be potential for reflecting glare. All registered windows are
automatically converted to Mirror and no material definition is needed.

3. This test is only implemented for Path tracing option. So make sure the option is
selected in Settings dialogue > Ray tracing tab.

4. Open the Render dialogue. Select the view point and direction either by entering the
coordinates or picking them from the model by pressing the button next to the input boxes.

5. Select Potential Glare option

6. Optionally change Camera type to Fisheye and set the view angle accordingly.
The view angle for fisheye is between 0 to 180.

7. Optionally change the font name/size in Render dialogue > Settings tab > Glare tab.
The Text format option has four different modes to display Month-Hour on the image:

– Hour 12 : 2pm
– Hour 24 : 14
– Mar-12 : March at 2pm
– Mar-24 : March at 14

8. Tick “Create Report” option to generate csv report for the rendered image.
The report contains information for every pixel that has glare occurrence.
This includes date and time, glare intensity in cd/m2, distance from the glare, field of view angle of the glare.

The report is created in [Drawing Filename]_Waldram\Images\GlareTest folder.

9. Increase the Subpixel sampling enough to render a sharp image. The noise in the image
is inversely proportional to the square root of this number. Press Render button.

 

 

Render FAQ

Glare DGP

For the assessment of daylight glare EN17037 please refer to the annual occurrence.

 

This is a point-in-time calculation. Radiance evalglare program is used to calculate DGP value.

According to En17037 glare is defined as:

Condition of vision in which there is discomfort or a reduction in the ability to see details
or objects caused by an unsuitbale distribution or range of illuminance, or by extreme
contrasts.

DGP is defined as:

the probability that a person is disturbed instead of the glare magnitude as a glare
measure. This new probability function is called daylight glare probability, DGP“.

It is an approach to consider both illuminance at eye level and individual glare sources of high luminance to estimate the fraction of dissatisfied persons.

According to En17037:

DGP can be applied to any daylight oriented indoor space which is mainly side-lit and where
the expected tasks are comparable to office tasks.

DGP values can be categorised in following ranges

Criterion Daylight Glare Probability(DGP)
Glare is mostly not-perceived DGP <= 0.35
Glare is perceived but mostly not disturbing 0.35 < DGP <= 0.40
Glare is perceived and often disturbing 0.4 < DGP <= 0.45
Glare is perceived and mostly intolerable DGP >= 0.45

To render an image for DGP calculation follow below process:

1. Set the Raytracing method to Radiance in Settings > Ray tracing tab

2. Set the Sky to clear CIE sky type Settings > Ray tracing tab.
Note: changes to sky type requires model reconverison for Radiance option.

3. As this is a point-in-time calculation, location, date and time have to be set in advance
via Project Settings dialogue > General tab.

 

Based on the provided threshold either of the two methods are used for detection of glare sources:

a. Calculate the average luminance of the entire picture and count every section as a glare
source that is x-times higher than the average luminance.

For this method try values less than 100: this factor multiplied by the average luminance in the entire picture will be used as threshold for detecting glare sources.

b. Take a fixed value and count every section as a glare source that is higher than the fixed value.

For this method try values over 100: the value is used as constant threshold in cd/m2;

Default option sets the threshold factor to 5.

4. Select a view point either by providing the coordinates on the input box or picking a point
within the room(work plane).

EN17037:

Testing position should be either a current used position of a person(workplace or often used position) or a position, which might be used and which might have a glare problem.
Such positions are usually close to the facade and/or facing facade orientations.

The viewing  direction of the measurement devices should face towards the facade parallel
to the floor and towards the azimuth direction of the sun. The height of the view point
should be in 1.2m height.

5. The camera type automatically is set to Fisheye. And the field of view angle is set to 180 degree.

6. Set the desired image quality and press Render. The yellow areas on the image displays
the glare sources.

7. DGP value along with other glare metrics are calculated and saved in a text file in

[ModelName]_Waldram\Images\GlareTest

dgp,dgi,ugr,vcp,cgi,Lveil: 0.416646 25.267189 30.691992 0.000000 36.333500 706.391235

Annual Glare DGP

This is an annual calculation of Glare DGP. Radiance evalglare program is used to calculate hourly DGP values.

According to En17037 glare is defined as:

Condition of vision in which there is discomfort or a reduction in the ability to see details
or objects caused by an unsuitbale distribution or range of illuminance, or by extreme
contrasts.

DGP is defined as:

the probability that a person is disturbed instead of the glare magnitude as a glare
measure. This new probability function is called daylight glare probability, DGP“.

It is an approach to consider both illuminance at eye level and individual glare sources of high luminance to estimate the fraction of dissatisfied persons.

According to En17037:

DGP can be applied to any daylight oriented indoor space which is mainly side-lit and where
the expected tasks are comparable to office tasks.

Minimum recommendation for glare protection

DGP(t) Maximum allowed exceedance during reference usage time
Recommendation for minimum glare protection 0.45 5%
Recommendation for medium glare protection 0.40 5%
Recommendation for high glare protection 0.35 5%

The reference usage time is set as the time between 8h – 18h on Monday to Friday througout
the year.

The calculation is the most lengthy calculation in the software. It is done against one point in the room
(work plane) for the duration of whole year. No image is produced. Instead a csv report is generated once the calculation is finished.
Which contains hourly DGP values in the weather file.

1. Set the Raytracing method to Radiance in Settings > Ray tracing tab

2. As this is annual calculation, the location and weather file have to be set in advance
via Project Settings dialogue > General tab.

 

Based on the provided threshold either of the two methods are used for detection of glare sources:

a. Calculate the average luminance of the entire picture and count every section as a glare
source that is x-times higher than the average luminance.

For this method try values less than 100: this factor multiplied by the average luminance in the entire picture will be used as threshold for detecting glare sources.

b. Take a fixed value and count every section as a glare source that is higher than the fixed value.

For this method try values over 100: the value is used as constant threshold in cd/m2;

Default option sets the threshold factor to 5.

EN17037:

Testing position should be either a current used position of a person(workplace or often used position) or a position, which might be used and which might have a glare problem.
Such positions are usually close to the facade and/or facing facade orientations.

The viewing  direction of the measurement devices should face towards the facade parallel
to the floor and towards the azimuth direction of the sun. The height of the view point
should be in 1.2m height.

4. The camera type automatically is set to Fisheye. And the field of view angle is set to 180 degree.

5. Press Render button for the annual calculation.

6.Hourly DGP values are saved in a text file in

[ModelName]_Waldram\Images\GlareTest\Annual Glare\glareAnnual.csv

Normal Image

1. Open the Render dialogue

2. Specify location by selecting the corresponding climate file in Project Settings General tab.

3. Pick Radiance or Pathtracing from the Raytracing Method box.

4. Set sky type, date and time on the Settings tab.

 

4. Select Existing or Proposed model from the Model box.

5. Camera position and look At can be set in two ways:
a. Either tick the Override settings from current view to setup the camera to AutoCAD current view. This option works better in AutoCAD Perspective mode.
b. Or press the View Position box button to select the position from the model. Repeat the process for Look At.

6. Horizontal field of view is set via View Angle box. The effect is similar to zoom in or out

7. The image box can be resized manually through resizing the dialogue or by setting the desired resolution in Resolution box and pressing the resize button.
If the resolution is bigger than the display screen the image is rendered in the given dimensions but displayed to the image box size.

Optional Settings under the Settings tab:

– Picture box image can display the progress by ticking the “Show Progress” option.

– Tick Interactive rendering to pan / orbit the rendered image within the picture box. Hold left mouse button down to pan the image. Hold right mouse button down to rotate the image.

Shading modes

There are three Shading mode supported in Path tracing mode:

a. Global Illumination which produces unbiased path-traced simulation of light paths. This is the default mode.

b. Ambient Occlusion option accounts only for the visiblity term. A cosine-weighted visibility factor calculated for the hemisphere of a surface point. An example is demonstrated here.

c. Local Shading mode quicken the rendering but removing diffuse inter-reflection from calculation. Phong-shading model is used to render materials with pre-defined three directional lights.

 

8. Set pixel samples number and press Render. The noise is inversely proportional to square root of this number: four times more samples are required to decrease the error by half.

Irradiance and Sky Component image

The process is same as described for rendering normal images. The maximum range of legend colours
is set in Settings tab > Irradiance and Falsecolor tab.

The minimum is always set to zero.  The maximum value can be set and is interpreted as follow:

Values between 0 to 100 is used as Daylight Factor or Sky Component ratio. Values above 100 are taken as absolute lux value.

 

If Radiance is selected as the rendering method,  two false color image modes are provided:

– Gradient option produces smooth interpolation between values on the image.

– If contour lines are desired rather than just false color image, the Contour Lines option can be used. These lines are placed over the normal Radiance picture rather than falsecolor image.

Contour Bands produces contour bands instead of lines, where the thickness of the bands is related to the rate of change in the image.

 

Note:

Radiance false color image uses pre-defined Radiance pm3d color palette with 8 colours.
The below image shows daylight factor contour lines with corresponding values set in legend, for an indoor scene.

An hdr file format is saved along the png format, loaded through Tools > Load hdr image, which can be used to display
the image with different legend colours without re-rendering the image.

Transient Shadow test image

Objects in Proposed and Existing group would cast shadows same colour as their material colour.

  1. Open the Toolbar>Settings dialogue and set Raytracing method to Path tracing option.
  2. Specify location by selecting the corresponding climate flie in Project Settings General tab

  1. Open the render dialogue by running “MBSRndr” command in AutoCAD.
  2. Specify the start and end datetime for the test in the Render dialogue>Settings tab
  3. Set the interval in minutes. One image is created per interval in Images\ShadowTest folder

 

New: A background texture image can be set by inserting a Raster image into the model. Make sure the image belongs to either of the analysis groups.

 

Tick New Shadow Only option to exclude part of the coloured shadow that already is rendered under the existing scenario.

  1. In Image tab select Shadow Test and pick the model group from the box.
  2. Set Camera mode to Perspective.
  3. Camera position and look At can be set in two ways:a. Either tick the “Override settings from current view” to setup the camera to AutoCAD current view. This option works better in AutoCAD Perspective mode.
    b. Or press the View Position box button to select the position from the model. Repeat the process for Look At.

 

  1. Horizontal field of view is set via View Angle box. The effect is similar to zoom in or out.
  2. The image box can be resized manually through resizing the dialogue or by setting the desired resolution in Resolution box and pressing the resize button.
    If the resolution is bigger than the display screen the image is rendered in the given dimensions but displayed to the image box size.
  3. Set pixel samples number and press Render. The noise is inversely proportional to square root of this number: four times more samples are required to decrease the error by half.

Render dialogue FAQ

Registration Steps

  • Type “FACADE” in command line to open the Facade Dialogue.
  • Enter mesh length (size of mesh in façade mapping in meters), mesh offset and select Highlight Facade Colour (Selected
    objects are highlighted using this colour).
  • Enter Name for Facade or select Auto Naming which names as “FACADE_1”, “FACADE_2” and so on.
  • Facade mapping can be done for 3d solids, 3d solid faces, Regions and closed 2d Polylines.
  • “Select Solids/Regions/Polylines” allows you to select 3dsolids, Regions and 2dPolylines from the model.
  • “Select Solid Faces” allows you to select faces from solid. For better results, filter selection by face.
  • Select the objects and click on “Register Facades”.
  • If you want to group them, make a group starting with FG and the group should contain either solids/Regions/2d polylines. The group then
    appears in the Selection list.

Calculation Steps

  • Go to Run dialogue and convert the model groups in Asset tab.
  • Go to tasks tab and select the calculation to run. Facade mapping can be done for VSC, APSH, Amenity, DF and Solar radiation.
  • Select the calculation type and you can see registered Facades in the model groups, select them. Click on “Add to
    list”.
  • Before running, make sure the settings are right.
  • Go to Settings dialogue and in Legend tab, you can select either gradient or non gradient.
    To get results on legend select “Display % of area for results” option. See Legend Settings Section for more details.

 

  • After changing the Settings, click on OK.
  • Go to Calculations tab, enter Sky sub division angle for VSC calculation (5 degree is suggested).
  • Run the calculations.

Result Steps

  • Each calculation has its own layer (ex: FACADE_1_VSC_PROPOSED_FACADE). If you select “both” groups you also get the loss
    (ratio of proposed and existing) in its own layer (ex: FACADE_1_VSC_LOSS_FACADE).
  • Use Realistic/Shaded visual style as mesh colours are not visible in Wireframe view.
  • The facade legend can be found in Waldram folder\\images\\FacadeLegend.

  • In Facade dialogue you can unregister all the registered Facades.
  • To delete the results and facade layers, click on “Clear Results” or use “DLTFCD” command.

View out criteria

View to the outside provides visual contact with the surrounding, so as to supply information for orientation, to experience the weather changes and to follow with the time over the day.

The view quality depends on

  • the size of the windows and the distance from the reference point to the window which together gives width of the view,
  • the outside distance of the view (distance from the inner surface of view opening to opposite major obstructions located in front of the opening)
  • the number of layers and
  • the quality of the environmental information of the view.

According to EN17037:

  • “The criteria for view out concerns the utilized area” section 5.2.2
  • “View to the outside should be assessed from selected reference points corresponding to where people are located within the utilize area”. section 5.2.1.
  • “Three levels of view out, horizontal sight angle, the distance to outside view, and the number of layers are assessed from reference positions.” section A.3

And regarding the required % of the utilized area for Horizontal Sight Angle and Distance Out C.3 states that

The reference points can be at any potential location within the utilized area of the space.

Implying that 100% of the utilized area is required for the criterion to pass. This parameter can be set to a different value within the software. Refer to the below section on where to set this.

The Criteria for Minimum View Out:

  • View Windows should have minimum dimensions (Width x Height = 1m x 1.25 m)
  • For all reference points on the utilized area, Distance to Outside elements should be larger than minimum value (6 m)
  • For all reference points on the utilized area, view windows should have a Horizontal Sight Angle higher than the minimum value (14 °)
  • A minimum fraction (75%) of the utilized area, the users of the space should be able to see at least the landscape layer.

Indicative points of the projection should be at points in the room where people are actually sitting (eyelevel 1.2 m over the floor) or standing (eyelevel 1.7 m over the floor).

View out assessment

Assessment of the view outwards from a given position

The Settings for View calculation can be set from Project Settings Results tab:

Outside Distance is calculated across the utilized area for each reference point. The rating is done as follow for each reference point:

The averaged distances to the outside obstructions are calculated for each of the three bands(minimum, medium, high) separately.
It is the average of all distances to the outside obstructions that fall within a specific radius(correspond to the band).
This is considered as valid only if the obstructions within the band obscure the view more than a specified threshold(e.g. 10% threshold in above figure).
Otherwise the band is regarded as having no obstructed view and no shortest distance is recorded.

A full sphere fisheye view is rendered for each reference point to accumulate distances on each band from all the openings.

The View Test dialogue can be used to visualize the three tests.

About Material Dialogue

Using of the Material Table requires enabling the option by ticking the Use Material Table box on the Materials Dialogue.

–  Using Material Table Mode

This enables you to assign materials reflectances or transmittance to selection of layers.
Once a material is assigned to a layer, through adding a record to the table,

  • its material type (eg. change of Diffuse to Thinglass) or
  • its material parameters (eg. Reflectance of 0.2 to 0.5)

can be modified freely WITHOUT a need to re-convert the model. Therefore this gives more flexibility on experimenting different materials and parameters for an analysis.

Model conversion automatically creates a record on material table for any layer that has not been assigned a material in advance.
Default diffuse material with reflectance read from layer color(r = 51, g = 51, b = 51 translates to 0.2, 0.2, 0.2) is used for any such layers.

As in below image they will be highlighted in red color to emphasis the difference and the need for revision.

Adding a new record or Removing one requires model re-conversion.

This is also the case on making any change to the model, like adding deleting objects or changes to the object layer.

–  Not Using Material Table Mode

Default diffuse material with reflectance read from object color(r = 51, g = 51, b = 51 translates to 0.2, 0.2, 0.2) is used.

Assigning Material by Layer

Using the material table you can assign materials reflectances or transmittance to selection of layers.
Once a material is assigned to a layer, through adding a record to the table,

  • its material type (eg. change of Diffuse to Thinglass) or
  • its material parameters (eg. Reflectance of 0.2 to 0.5)

can be modified freely WITHOUT a need to re-convert the model. Therefore this gives more flexibility on experimenting different materials and parameters for an analysis.

  1. Open the Project Settings dialogue and navigate to Materials tab and tick Use Material Table box.
  2. Select layer names from the layer list.  You can select one or multiple layers.

Use Filter Layer name box to filter the list.
Tick Hide MBS Layers to remove all MBS specific layer names from the list.
The layer list displays only the layers that do NOT have any material assigned to. This works as a safety checking to know which layers have been left with no materials.

  • Select a material from the list of materials on the right side. A predefined list of materials is available.
    The reflectance and transmittance values are taken from BS 8206 Part 2 2008 Table A.1.These are grouped in four categories of Ground, Internal, External, Paint Colours. You can create custom materials and group. The procedure is explained further down.
  • Press Add Selection to assign the selected material to the selection of layers. New rows are created on the Material table.
    On adding the rows to the Material table the selected layer names will be removed from the top layer list.
    So that for the layer list, as mentioned above, to display only the layers that do NOT have any material assigned to.

 

Changing a Layer Material

  1. Select one or multiple rows from the material table for which you want to change the material.
  2. Select the desired material from the top Material list and press Edit Material for Selected items.
    The assigned material for each selected row will change to new material.

Creating custom Material in Material Library

It is possible to create new material definitions other than the predefined ones.

  1. Open the Project Settings dialogue and navigate to Material Library tab.
  2. Insert the new Material Name.
  3. Select the Group from the list. You can write new group name and it will be added to the group names.
  4. Select Material type from the box. Supported materials are:
  • Diffuse surface reflects light uniformly over the entire reflecting hemisphere. A Lambertian(or diffuse) surface appears equally bright from all viewing directions.
    The reflectance parameter represents the fraction of the incident energy that is reflected at a surface. The parameter has three components which varies from 0 to 1.
  • Mirror (specular reflection) surface only reflects light in one specific direction.
  • ThinGlass is a special case of dielectric, infinitely thin and therefore does not change the transmitted ray direction. It is modeled as a single surface. The default refractive index is 1.52.
    Transmittance is the ratio of the total transmitted light to the incident light which includes multiple inter-reflections in a layer of glass.
    The parameter is a single value from 0 to 1- Reflectance field is disabled as it is a function of angle, refractive index of the material and transmissivity.
    Transmissivity applies to a single pass of light through a layer of glass and excludes multiple interreflections within the medium.
    ThinGlass is translated to Radiance glass material. Transmittance value is converted to transmissivity for the Radiance rad file.
  • Dielectric: it assumes the surface to have a volume (ex. Solid). The ray refracts on entering/existing the material.
    Roughness value(available on Path tracing option only) greater than zero results in a glossy reflection and transmission.
    Zero corresponds to a perfectly smooth surface, and value 1 to a very rough surface.
  • Translucent material is a mix of diffuse reflectance/transmittance and perfect/glossy specular reflectance and transmittance. It describes diffuse and glossy specular reflection and transmission through the surface.
    Translucent parameters are well described in this link: http://www.schorsch.com/en/software/rayfront/manual/transdef.html
  • BSDFRadiance material, only valid on Radiance method, is to define material for complex glazing system.
    The input is an xml file containing BSDF matrix data. This file can be generated using WINDOW 6.0 BERKELEY LAB application.
    Please follow instruction on BSDF Files for Radiance Renderings page.
  • TransTree is a mix of Diffuse Reflection(representing leaves) and  Specular Transmission(the gaps). See How to assign the Materials for Trees? for more details.

How to assign the Materials for Trees?

TransTree is a mix of Diffuse Reflection(representing leaves) and  Specular Transmission(the gaps). This material is suitable for simulating trees on BRE (ADF, VSC, APSH) or Daylight Factor calculations. The Reflectance value on VSC, ADF calculations only reflects in terms of  the colour as no reflected light is accounted for. The Transmittance value is the overall transparency of tree crown as the ray enters and exists the tree volume. Follow the below steps to assign tree material to a layer:

  • Put the tree objects with same transparency to a layer.
  • Then go to Project Settings – Materials tab and assign one of the predefined BRE tree materials.
  • The trees mentioned BRE Site Layout for Daylight & Sunlight Appendix H Table H1 are included in the material library.
  • It is also possible to define a custom tree material.
    • Go to Project Settings – Material Library section
    • Create a new TransTree type material
    • The reflectance values are used for the colour of the tree.
    • The transmittance is converted automatically to consider the overall transparency of the tree crown as the ray enters and exits the tree volume.
    • For example 50% transparency should be input as 0.5 which will then be converted to 0.707 (√0.5). This can also be seen on material preview area.

How to assign the Materials for Balconies?

  • Balconies are supported for all calculations including Ray-traced based (Daylight Factor and Climate) and BRE (VSC, APSH and ADF).
  • Put the balcony objects with same transparency to a layer.
    • Region or objects with single face should be used.
    • Using objects with multiple faces may result in the transparency being applied multiple times.
  • Then Go to Project Settings – Material Library section
    • Create a new ThinGlass type material
    • The transmittance value should be in put as unit value e.g. 0.8 for 80%
    • Refractive index of 1.52 is define as default.
    • Press Apply to save the changes.
  • Then Assign the material to the layer with balcony objects on the Materials tab. Refer to Assigning Material By Layer topic for details.

How to setup up a model for Assigning the Materials?

Put objects in the model to their corresponding layers. Normally for indoor calculations like Climate or Daylight Factor the scene is divided into two groups of objects, external obstructions and room internal surfaces.

 

and What happens to registered Windows Glazing Transmittance?

 

The detection of room indoor surfaces on Revit edition of the software is done automatically and can be visualized by Highlight Room interior command.

For AutoCAD edition separating floors, walls and ceilings objects and put them in their layers(e.g. all walls objects to “wall” layer) can be a challenge.
Any solid object has to first get exploded to access the individual surfaces. Care must be taken to put back the exploded objects back into their original ClassicGroup.

The ExtractRoomSurfaces command is a utility command in AutoCAD that automatically extracts floors, walls and ceilings and put them in corresponding layers.

Raytracing Settings

Two Monte Carlo backward ray tracer are provided: Path tracing and Radiance software.

  • Iterations N: “The error in the Monte Carlo calculation of indirect illuminance will be inversely proportional to the square root of this number:four times more samples are required to decrease the error by half.
    • In Radiance option: This value corresponds to ambient divisions “–ad” parameter:
      number of rays casted from the surface point to its hemisphere about the normal to estimate the radiance values. Each ray if not absorbed or terminated spawns to N more rays.
    • In Path tracing: Since no branching happens on each bounce this value determines the total number of indirect paths initiated from the sensor.
  • Indirect Bounces:
    • In Radiance: This is the maximum number of diffuse bounces computed by the indirect calculation. A value of zero implies no indirect calculation.
    • In path tracing: This is the minimum number of bounces. Russian Roulette probability is applied after reaching this number.

Gradient Legend

Gradient legend has five different colour options. All options except MBS and Rainbow allow users to change the colour. The minimum and maximum values are pre-defined for all the calculation types which support legend creation. The values can be changed by user if required. All options except Rainbow create 21 colours in total. Rainbow creates 25 colours in total. Intermediate colours are added to avoid colour contrast between values in two intervals. The breakdown of intermediate colours is as below:

  • Two colour: 2 for the given colours and 19 interpolated colours between them.
  • Three colour:  3 for the given colours and 9 interpolated colours between first and second and second and third colour.
  • MBS colour: 11 for the given colours and 10 for the mid colour between them except the last one.
  • Custom colour: 11 for the given colours and 10 for the mid colour between them except the last one.
  • Rainbow colour:  7 for the given colours and 18 for the intermediate colours between them. (3 interpolated colours between each consecutive colour except the last one)

 

Legend interval

The interval for legend values is created by dividing the min and max values equally to the legend colours.
Interval values for legend colours are calculated using the formula (Max value – Min value) / (total colours in legend – 1). The last colour  is for all values greater than max  therefore (total colours – 1) is used.

For example, The interval of values per MBS legend colour for VSC legend with min of 0 and max of 27 will be calculated as below.
(27-0) / (21-1) = 1.35

Non-Gradient Legend

There are no default values for non-gradient legend mode. Users must  define the range for each calculation type before running the calculation. If non-gradient legend values are not defined for the calculation, the default gradient mode is used.

Select the calculation type on the combo box to define a non-gradient values. Then choose a colour and enter a value. The values must be in ascending order. The first value will be the minimum value and last value will be maximum value for any calculation.  The ratio colour and values fields can be left empty if the calculation is only being run for Proposed scheme.

BRE Non-Gradient Legend

If BRE option on Non-Gradient mode is ticked, VSC and APSH legends will be customised according to the BRE criteria. The legend will be created with just three colours for Pass, Nearly Pass and Fail. The colours can be changed by the users. The pass values for VSC and APSH is taken from Project settings Assessment criteria section.

For Example, for VSC calculation if the result >= 27 (or) loss < 20 % then it passes, if the result >= 26 (or) loss < 21 % (Tolerance = 1) the it is Nearly Passed, otherwise it will fail. The legend will show Pass, Nearly Pass and Fail results. If the calculation is run for neighbour scheme only one legend is created.

Minimum recommendation

This is to be checked in the reference point at the centre of the window width and at the
inner surface of the aperture (façade and/or roof). For multiple apertures in different façades it is
possible to cumulate the time of sunlight availability if not occurring at the same time. The reference
point is minimum 1,2 m above the floor and 0,3 m above the window sill if present.

NOTE 1 If the sill height of the window is higher than 1,2 m above the floor, the reference point is located 0,3 m
above the window sill. If window is without sill the reference point is located 1,2 m above the floor, Figure D.3.

NOTE 2 To allow flexibility for rooms orientation the angle of window normal αwn,s = 120° measured from
South and the minimum sun height γs,min are applied. Solar altitudes below those stated in Table D.1 are neglected in the evaluation.

Minimum recommendation for exposure to sunlight

The minimum recommendation is that the room should receive possible sunlight for a duration
higher than 1,5 h (supposed to be cloudless) on March 21.

Table A.5 proposes three levels for exposure to sunlight.

Sunlight Exposure
Recommendation for minimum exposure to sunlight 1.5 h
Recommendation for medium exposure to sunlight 3.0 h
Recommendation for high exposure to sunlight > 4.0 h

Run calculation

The test date can be changed on Project Settings > Climate Daylighting tab. The default date is set for March 21.

Open Run dialogue and select Sunlight Exposure to run the calculation.

 

Cutback dialogue steps

  1.  Open cutback dialogue by entering CUTBACKMBS command.
  2. Select group
  3. Select Sky type. For ROL cutback Sky should be set to Uniform.
  4. Orientation is the surface orientation where the calculation point lies on.
    Set the Orientation to Vertical for Windows, and Horizontal for ROL
    Although ROL calculation is for a point on a horizontal surface(working plane), the rendered image for points deep in the room might come in low resolution.
    You may pick Vertical orientation in this case for ROL to get a higher resolution Waldram image. 
  5. Select Room or Window from the box and press Select.
    If Room option is selected, a point within the room needs to be selected too.
  6. Press “Create Diagram” to render Waldram image.
    To start drawing shape press button. There are three tools available to draw shape:

    •  Horizontal mode: draws droop line on the diagram. The result is straight horizontal line in 3d.
    •  Vertical mode: draws vertical line.
    • Freehand mode: draws polyline on the diagram with any number of segments.

    To close the shape press the start polyline
    To close the shape at specified high, press and pick a point on the image. The shape will be closed by adding three perpendicular segments as in the image below.
    [optional] You may press “Cut diagram” button to cut the drawn shape on the image and update Sky Component value. This does not create/cut the 3d model. Instead it can be used to check whether the resulting Sky Component is close to the desired value.
    [optional] To draw new shape it is suffice to press Erase button.

  7. Pressing “Create 3D Object” will create the 3d object(s) in the model from the shapes on the diagram (The user can later subtract the created object from proposed objects).[optional] Tick “Subtract from Proposed” to automatically subtract the shape on the diagram from the 3d proposed objects. The subtracted object is put into “CutbackInterference” layer in red colour.
    [optional] Tick “Re-Create diagram” to automaticaly reconvert and create the new diagram. In case of room new contours are calculated.

Register By Model

  • List of layer names
    1. Room: Room_Polylines
    2. Window: Window_Polylines
    3. Building Outline: Building_Polylines
    4. Building Detail Block: Building_Polylines
    5. Extra Building Outline: Building_Sub_Polylines
  • Building Detail Block
    1. Run –insert command on Autocad command line and type BuildingDetail.dwg
    2. Specify the base point, scale factor and rotation angle.
    3. Add the building name and modify starting floor if necessary
    4. Move it inside the respective building polyline (The base point of the block should be inside). It should be on the Building_Polylines Layer
  • Combine Pre Reg check box
    This disables the buttons for pre reg Step 1 and Step 2. The register by model will be performed in one go with Step 3 directly. The pre reg rooms and windows step are done in background and can be enabled by unticking the Combine Pre Reg option if necessary for debugging. This option will also work when Without Rooms option is checked.
  • Step 1: PreReg Rooms
    1. Updates building names from blocks with building and starting floor names.
    2. Determines Building and Floor for Rooms based on Building_Polylines and Z of room.
    3. If current Room is higher than 0.5m(this value can be changed if rooms in same floor are in various height) than the previous Room then it is put on a new floor.
  • Step 2: PreReg Windows
    1. Determines Building and Floor for Windows based on Building_Polylines and average height of Pre-Registered Room_Polylines in a floor.
    2. If the centre of a window is higher than or equal to the average height of rooms in the current floor and smaller than the floor above then it is put on current floor.
    3. All windows whose centre is higher than or equal to average height of the rooms in the last floor they are put that last floor.
    4. If Without Rooms is ticked, the window floors are determined using a fixed height of 2.5m. If current window’s centre is higher than 2.5m of previous window’s centre, current window wiill be put on new floor.
  • Step 3:Registration
    1. Registers windows and rooms to the floors and building determined during pre-reg steps
    2. Attaches windows which are within the search tolerance (default: 1m) range of rooms to them.
    3. Rooflight windows will be attached to rooms if they are within the room even if they are further away than the search tolerance.
    4. If any window is not correctly attached to room, it can be manually attached from Register dialog /Update Mode /Room. Update
    5. Summary will show count ofroom/window polyline which are not registeredwindows which are facing inside room windows, which are not attached to rooms and windows which are slightly inclined
  • Changes to building polyline
    In prior version, the window and room numbering used to be out of order if the window are located in gaps.
    The solution was to draw the building polyline close to the window.


    The building polyline can now be drawn in much simpler way. Building polyline doesn’t have to follow the window polyline too closely as long as it is closest to the window centre in any directions. The distance used to be on window normal direction in the past.
  • Notes
    • The building polyline determines start and order of window and room names.
    • Floor name combo box must have enough entries for all floors to be registered and must be on correct order
    • Room and window names will be automaticaly added using the current naming convention if the list does not have enough entries.
    • There is no need to add building names to the BuildingList.txt file as they are automatically added from the building detail blocks.
    • Each step can be undone using single Undo as a new Undo group is created for every step

Renumbering

Renumbering can be useful if windows and rooms are added or removed from the model after the initial registration.
It can also be useful if the numbering of the windows needs to start from a different position.
Renumbering can be done for Partial Floor, Single Floor or All Floors in a building. Single and All Floor renumbering need the building polyline and building name block (Both of them must be on the building_polylines layer).

  • All Floors
    Once Re-Number button is pressed on Register dialog Update mode and All floors option is selected, promt is given to select a building polyline. Then the rooms and windows in all floors above the starting floor (building detail block) will be renumbered based on the selected building polyline. This doesn’t alter the floor references of rooms and windows. Also if there are any window/room within the building polyline but have different building address to one in building detail block, they will not be included in the renumbering process.
  • Single Floor
    Once Re-Number button is pressed on Register dialog Update mode and and Single floor option is selected, promt is given to User is prompted to select a building polyline. Then, prompt is given to Select one registered window in the floor to Re-Number. Then the rooms and windows in the floor of the selected window will be renumbered based on the selected building polyline. This process considers windows/rooms which are already registered in the floor and building address only. If there is a window with in the building polyline and in the same height as other windows in the floor but is registered with a different floor or building name, then it will not be part of the renumbering process.
  • Partial Floor
    Once Re-Number button is pressed on Register dialog Update mode and and Partial floor option is selected, promt is given to select a reference polyline. Then, prompt is given to Select the windows to be renumbered. Then, Starting window number can be entered without the prefix e.g. 10 for W10. Once window renumbering is complete, prompt is given to confirm if rooms should be renumbered too and starting room number can be entered if affirmed.
    This option is useful if windows need to be renumbered in noncontinuous manner for flats within the same building as shown in below image.

    The partial renumbering cannot automatically handle duplicates if existing window which is not being renumbered uses the same number. In order to avoid duplicate issue, partial renumbering should be done for higher window numbers. For example, Let’s say Flat 1 window need to start from 10, Flat 2 windows from 20 and Flat 3 windows from 30. If Flat 1 is to be renumbered first and window numbers will conflict with W10 on Flat 2 and W11,W12 on flat 3. However, if Flat 3 is renumbered first, followed by Flat 2 and then Flat 1 the conflict can be completely avoided as shown on the image below.