Colors from Points to VDB : troubles

[grendizer]

Hi all, I'm trying to transfert colors (Cd) from a point object to a volume VDB object. For that I'm using the vdbfromparticles1 node and in its parameters, I'm using the point attribute "Cd".

However I have 3 problems :

- The shape of the VDB does not look like the shape of the point cloud.

- The colors are not transferred.

- When I play the stop the timeline, the "attribute" menu reverts to "no entry".

I attach a picture and a video to explain what happens. Sorry for my bad english!

Question_Hou_Points_Colors_to_Volume.mp4

[Sean-R]

Hi David,

I have included a simple scene to show how to add and show colours on a volume.

The reason that your volume looks like that is because of how Houdini visualises vector volumes in the viewport. You will need to drop down a volume visualise node, set Density Field to "density" and Diffuse Field to your colour volume. I reccomend "Cd" as this sticks with Houdini's naming conventions and you can name your colour volume on the VDB to Particles node where it says VDB name under the attribute dropdown.

I'm not sure what's causing the other issue unfortunately

Thanks,

Sean

 

coloredPointsToVolume_SeanR.hipnc

[grendizer]

Thanks a lot for your help Sean. It was mostly the volume visualise node that was missing.

- Problem 1 : when I put the display flag on the volume visualise node, the shape is correct.

- Problem 2 : when I put the display flag on the volume visualise node, the colors are correct.

- Problem 3 : the "attribute" menu reverting to "no entry" was due do going back to frame 0. I set the timeline to start at frame 1 and voila!!

Gday

Edited August 26, 2021 by grendizer