Add visualization for SDF/Levelset Volume Grids #88599

New Issue

Angelo Tartanian · 2021-05-26T17:31:58+02:00

Angelo Tartanian commented

2021-05-26 17:31:58 +02:00

Problem:
OpenVDB Levelset/SDF grids don't render properly when imported into Blender. This is because Blender considers all volume grids to directly represent some quantity in space such as density, but SDF Level sets instead are a representation of the boundary of a volume.

Solution:
Add a way for Volume Grids to store an alternate grid used for display purposes and use that to store a fog volume version of the original SDF/Levelset.

Alternatives:

Store a mesh of the boundary surface

- Pros
  - SDFs really are a representation of a surface (though, not usually a discrete surface like a mesh, rather a functional implicit surface)
- Cons
  - User loaded a Volume but now sees a Mesh. The data block still shows up as a Volume.
  - More costly to compute the mesh representation of a Volume than the Fog version
  - Adding a volume to mesh modifier results in the same display, since we were already showing a Mesh before we formally converted the data.

Add a new way for the renderers to display SDFs

- Pros
  - Valuable to see the SDF data directly either as a distance field or as an implicit surface
- Cons
  - A much bigger project that would involve research and potentially large changes to Workbench and Eevee

**Problem:** OpenVDB Levelset/SDF grids don't render properly when imported into Blender. This is because Blender considers all volume grids to directly represent some quantity in space such as density, but SDF Level sets instead are a representation of the boundary of a volume. **Solution:** Add a way for Volume Grids to store an alternate grid used for display purposes and use that to store a fog volume version of the original SDF/Levelset. **Alternatives:** # Store a mesh of the boundary surface - Pros - SDFs really are a representation of a surface (though, not usually a discrete surface like a mesh, rather a functional implicit surface) - Cons - User loaded a Volume but now sees a Mesh. The data block still shows up as a Volume. - More costly to compute the mesh representation of a Volume than the Fog version - Adding a volume to mesh modifier results in the same display, since we were already showing a Mesh before we formally converted the data. # Add a new way for the renderers to display SDFs - Pros - Valuable to see the SDF data directly either as a distance field or as an implicit surface - Cons - A much bigger project that would involve research and potentially large changes to Workbench and Eevee

Angelo Tartanian self-assigned this 2021-05-26 17:31:58 +02:00

Angelo Tartanian commented

2021-05-26 17:31:58 +02:00

Added subscriber: @AngeloTartanian

Philipp Oeser commented

2021-05-26 17:51:26 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-05-26 17:51:26 +02:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Philipp Oeser commented

2021-05-26 17:51:26 +02:00

Interesting.
This would need to be confirmed as a TODO of some sort, but this is something the module devs need to do.
It certainly is out of scope of the bug tracker.

Interesting. This would need to be confirmed as a TODO of some sort, but this is something the module devs need to do. It certainly is out of scope of the bug tracker.

Hans Goudey commented

2021-05-26 17:54:48 +02:00

Changed status from 'Needs Developer To Reproduce' to: 'Confirmed'

Amos Manneschmidt commented

2021-10-25 17:54:55 +02:00

Added subscriber: @AmosManneschmidt

Brecht Van Lommel added this to the Render & Cycles project 2023-02-07 19:08:06 +01:00

Philipp Oeser removed the

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Add visualization for SDF/Levelset Volume Grids #88599

Store a mesh of the boundary surface

Add a new way for the renderers to display SDFs