Points Distribution node density attribute field #82376

New Issue

Dalai Felinto · 2020-11-03T18:02:40+01:00

Dalai Felinto commented

2020-11-03 18:02:40 +01:00

The density attribute field works as a mask multiplier relative to the "density".

Change the density field somewhere should not change the distribution elsewhere.

The density attribute field works as a mask multiplier relative to the "density". ![image.png](https://archive.blender.org/developer/F9182921/image.png) Change the density field somewhere should not change the distribution elsewhere.

Dalai Felinto commented

2020-11-03 18:02:40 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Dalai Felinto commented

2020-11-03 18:02:40 +01:00

Added subscriber: @dfelinto

Jacques Lucke commented

2020-11-11 16:41:16 +01:00

Added subscriber: @JacquesLucke

Jacques Lucke self-assigned this 2020-11-11 16:41:16 +01:00

Jacques Lucke commented

2020-11-11 16:41:16 +01:00

I'm working on this node today to make it a bit more usable. Might not implement all the design yet.

Jacques Lucke commented

2020-11-11 17:38:51 +01:00

There is one issue I did not foresee: the vertex group data is stored in the mesh, but the vertex group names are stored on the object (for whatever reason). That means, that currently, the node tree does not know about the vertex group names. Therefore, the node has an index input instead of a name input.
I think we can solve this somehow, but I have to think about it a bit more to find a good solution.

2020-11-11 17-33-13.mp4

There is one issue I did not foresee: the vertex group data is stored in the mesh, but the vertex group names are stored on the object (for whatever reason). That means, that currently, the node tree does not know about the vertex group names. Therefore, the node has an index input instead of a name input. I think we can solve this somehow, but I have to think about it a bit more to find a good solution. [2020-11-11 17-33-13.mp4](https://archive.blender.org/developer/F9261299/2020-11-11_17-33-13.mp4)

Miro Horváth commented

2020-11-11 20:17:00 +01:00

Added subscriber: @MiroHorvath

Miro Horváth commented

2020-11-11 20:17:00 +01:00

Hi @JacquesLucke , I'm just curious, is there a specific reason(performance maybe?) why you have Nodes modifier assigned to PointCloud in this demo? thanks

Jacques Lucke commented

2020-11-11 20:28:18 +01:00

It's a technical limitation right now. To make this work I had to change how modifiers are evaluated internally. Making this change for point clouds first was significantly easier, because I could not break as much existing functionality. Besides instancing, this change also allows a modifier on a point cloud to output a mesh.

Doing the same change for modifier evaluation on mesh objects should be possible, but is more difficult if one wants to avoid regressions of existing functionality.

It's a technical limitation right now. To make this work I had to change how modifiers are evaluated internally. Making this change for point clouds first was significantly easier, because I could not break as much existing functionality. Besides instancing, this change also allows a modifier on a point cloud to output a mesh. Doing the same change for modifier evaluation on mesh objects should be possible, but is more difficult if one wants to avoid regressions of existing functionality.

Dalai Felinto commented

2020-11-11 21:04:36 +01:00

@JacquesLucke fascinating. Indeed in Blender you can duplicate an object, still share the same mesh, yet rename the vertex groups. That said I hope/don't think this is a blocker. We need a lookup table in the geometry from the object it was created from. This problem is particularly interesting when we try to deal with location, rotation, ... as attributes.