Calculation at cut-planes

Batch calculation of daylight levels at cut-planes

This is a feature of the Radiance Pro module.  Please ensure you have this module from the "downloads" page.

ODS Studio is aimed primarily at carrying out rapid Radiance simulations of multiple zones and cut-planes efficiently and quickly.  This tutorial outlines the method for calculating the daylight factor at multiple cut-planes in a large multi-zone model using stencils.

A final .blend Blender file for this workflow is included at the bottom of this tutorial.  The .blend file includes a sample of results from levels throughout the multi-storey building.  The workflow is as follows:

  1. A model was created in Blender of a multi-storey office building using array modifiers.  Surrounding buildings were included and material colors and properties were set as per the previous tutorial on Perspective rendering.
  2. The floor of each level was selected and these polygons were duplicated and separated to form a separate object.  These copies of the floor polygons are going to become our "stencils" that we use to calculate the daylight factor at.
  3. Move the stencil object to a fresh layer.  Press 'g' and then type '0.8' to move the stencils up 0.8 meters.  This will position the stencils at a working plane 0.8 meters above the floor level.
  4. Press spacebar in the 3D viewport and start typing "Explode Linked Flat Faces" to use this operator to explode the polygons into separate individual cut-plane objects. 
    • Note: All these cut-plane objects must be flat in the z-direction otherwise the calculation will not proceed at step 7 below.
  5. In the ODS Studio Scene Properties panel select the "Radiance -> Stencil" menu.  Set the properties for resolution, ambient accuracy and ambient bounces.
  6. Select all layers except the layer with your stencils on it (or any other layer you don't want to include in the base-octree which will be used for the calculation) then press 'a' to select all objects and then press the "Write Case File" button and then the "Generate Octree" button.  Check the ODS Studio Terminal Window to check that everything exported corrected with no errors.
  7. Move to the layer that has your stencils in it.  Press 'a' to select all the stencil objects and then press the "Trace at Stencils" button to start calculating the daylight factors at each cut-plane.
    • Note: If you are on a Linux or Mac machine and you have set the number of CPUs in the top-right corner then you will make use of all processors to do the calculation.  This speeds up the calculation significantly.
  8. Post-process the HDR images in the UV/Image Editor window to generate false-color plots or batch-process results into a spreadsheet as outlined in a later tutorial.
Icon Cutplane Render Tutorial ODSv1.1 (5.9 MB)