Seeking validation for FDS data extraction workflow (Plot3D to Blender via ParaView)

[mandomp]

Hi everyone,

Last year, I attempted to extract fire simulation data from FDS to use external rendering engines and achieve better visual output than Smokeview. Having no prior experience with Houdini, I had to put the project on hold. A year later, I’ve successfully developed an alternative pipeline: FDS → ParaView → PLY Point Cloud → Blender (Geometry Nodes).

My workflow follows the general principles of Ian Fong's tutorial (https://www.youtube.com/watch?v=Kfqr33l2LBI), summarized as follows:

1. FDS Setup: Added the following lines to the source code:
   &DUMP NFRAMES=60, DT_PL3D=0.04, WRITE_XYZ=.TRUE. /
   &PLOT3D_QUANTITY(1:5)='U-VELOCITY','V-VELOCITY','W-VELOCITY','HRRPUA','SOOT DENSITY' /
2. Extraction: Generated .xyz and .q (Plot3D) files for each timeframe.
3. Sequence: Sequentially renamed .q files for ParaView compatibility.
4. ParaView Processing: Used filters to isolate specific data points and exported them as .ply point clouds.
5. Blender Post-processing: Used Geometry Nodes (Points to Volume) to recreate smoke behavior based on the extracted data.

The Issue:

The extracted variables in ParaView have generic CFD labels. Based on a side-by-side comparison between Smokeview and ParaView, here is my current interpretation:

1. IBlank: Values are 0 or 1. I am unclear on its exact representation.
2. Density: I suspect this represents Air Temperature, as it starts at a value of 20 (matching my initial ambient temperature of 20°C).
3. Momentum (0, 1, 2): I assume these represent the Velocity Vectors (U, V, W). When combined via the "Magnitude" filter in ParaView, they seem to represent the smoke flow intensity.
4. StagnationEnergy: Visually resembles the HRRPUV (Heat Release Rate per Unit Volume) parameter.
5. Pressure: Also resembles HRRPUV or another scalar field.
6. Point (0, 1, 2): The XYZ coordinates of the data points.

My Questions:
I am missing the SOOT DENSITY variable in this list. I need it to drive the smoke density/darkness in Blender's shader.
Can anyone expert in FDS confirm if my mapping of these variables is correct?
The FDS manual entry for DT_PL3D is still a bit unclear to me regarding exactly what it maps to each Plot3D slot.

I am attaching the FDS source code, ParaView screenshots, and a demo video of the Momentum field post-processing in Blender. Any feedback or confirmation would be greatly appreciated!

prova_houdini.txt




https://github.com/user-attachments/assets/1eb2cef7-61e7-44cb-abc8-8e539adb7ed9