Report: 3D Design Workflow starting from 3D CAD

I released the report, “3D Design Workflow starting from 3D CAD --Simulation and Presentation using Renderers.”
Introduction: Many corporations have compared and evaluated product design by the finished drawings of proposals during the design phase using computer graphics from the 1990s, such as architectural competitions in general contractors and evaluating automobile body shapes in carmakers. Now, open-source software has made it possible for individuals and NPOs with small budgets to conduct these evaluations. It means that individuals can opinion on the design stage, the upstream product manufacturing process. Individuals specifically might be opinion leaders to agree on their desirability by comparing the proposals, while feasibility and viability studies with the finished drawings. Therefore, the 3D design workflow should start from 3D CAD, not the 3D modeling functions of computer graphics software. Also, the computer graphics may be a simulation tool, not only a presentation tool, for the feasibility studies. I want to show the workflow from FreeCAD as a 3D CAD to Radiance as an optical simulation program and POV-Ray and Blender as presentation tools, especially for the beginners in computer graphics and digital art. In this report, I use mesh data as the CAD data for the adaptivity to the product design since the meshes adapt to all of the product’s shapes and are available for exporting and importing. However, the mesh data have some surface smoothing technique difficulties. Therefore, I want to mention some solutions to the issues while describing the workflow procedure.
*Downloads of project files in the report are available on the following site:


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I added Chapter 9, “Creating Boundary Conditions,” to the previous report, “3D Design Workflow starting from 3D CAD,” as an appendix from page 28 to page 36. I would be happy if you suggest anything about my report and project.
URL of the Report: BEYOND THE NET: TOOLS - Report09

My website: Experimental Project of Collaboration for Art, Science, and Education beyond the Net: TOOLS BEYOND THE NET: TOOLS

Hi Yoichi,

thank you for sharing this report! Since Radiance is mainly used for building- and room-scale simulations, that are more tailored to answer questions about illuminance, contrast etc., we do not see many such approaches to align lighting simulation with visualisation tasks. In object design, the difference between simulation and visualisation may be more subtle though. I think you arrived at some really convincing results, in particular since you present a complete work-flow starting from 2D sketches.

For the wine glasses, trying out the photon map in Radiance may be interesting since that would account for caustics. Did you try that, or are you planning to?

What I am currently struggling with is the transition from “specularity” to “metalness” parametrisation, that happens with most renderers. Is it correct that you can still use both in Blender / Cycles? In your report you still set specularity in your visualisations, with a similar rationale as in Radiance. Did anyone find a way to directly translate from one to the other?

Best, Lars.

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Hi Lars,

Thank you for the reply. I have not known about photon mapping and caustics before reading your reply. I want to try the photon mapping of Radiance. POV-Ray has a photon mapping function, so I want to compare the real caustics with simulated caustics by Radiance and POV-Ray.

I corrected the glass material values, including the specularity, during trial-and-error rendering independent of real physical properties, as written on page 16 of my report. So, as shown below picture, I have no rationale for the translation rule except for looking at the real coaster’s reflected image on the wine glasses and water.

After starting this wine glass simulation, I was aware of the importance of comparison with real wine glasses. I bought wine glasses and am tracing the shape of the wine glasses. I am also in the process of photographing the wine glasses.

Could you tell me if there is any image of caustics on the glass and water in this picture? I recognize the caustic on the floor, but I still don’t fully understand caustics. I believe that Radiance is worth making case studies for simulations in the workflow. I will post the progress of my experiments in this forum. I am happy to get advice and suggestions.

If you have already posted about the problem of the transition from “specularity” to “metalness” parametrisation, please let me know in the forum thread?

Best regards,
Yoichi Mizomata