vertex color 3dsmax

[Anonymous]

hi, i'm trying to convert my old material (#26) to new Arnold material. its being driven by vertex color node . This wiring doesn't seem to work...can anyone please help? Thanks!

[RGhost77]

In 2019 Max you can use OSL node "UVW Cahnnel" with Map Channel == 0 to get vertex color from object.

[Anonymous]

Care to expand on this explanation? I can't get vertex colors to render at all with Arnold. And there is nothing in the documentation about vertex color support.

If a model only has vertex colors then it likely doesn't have UVW coordinates, which my models do not, which I assume is why "UVW channel" OSL node is not doing anything.

Any ideas on how to fix this problem?

[RGhost77]

Vertex color == vertex uvw coordinate, where R==U, G==V,B==W. So if you have vertex color on object that you have UVW mapping on it.
Vertex color map channel it's just custom name of UVW channel 0.

[madsd]

Made a video, maybe this will help, atleast I show how to paint vertex colors and render them.
You can use the OSL UVW channel map and set it to the channel you export the vertex colors to, which can be any, by default 0 as already mentioned.

https://knowledge.autodesk.com/support/3ds-max/getting-started/caas/screencast/Main/Details/2a01656f...

[Anonymous]

Thanks for the reply. I kind of understand what you're saying, but I don't know if it helps me.

I've got an imported object with vertex colors only. No UVW mapping. It displays the vertex colors fine in the viewport.

I created a shader OSL UVW CHANNEL (map channel 0) piped into the base color of an arnold standard surface.

Render in Arnold 2019 and 2020

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Ideas? Thanks

[madsd]

please upload a section of the wheele with green paint on.
We can check if your data sits in a different channel or quickly narrow down the workflow issue.

[Anonymous]

Awesome, thanks.

Attached is the wheel.

I did watch your video actually. Maybe I'm missing something simple.

Here is additional info on the origin of the mesh:

1) Mesh created from FARO point cloud data in CloudCompare.

2) Exported as a PLY

3) Imported into Meshlab

4) Exported as a DAE

5) Imported into 3DS Max.

I even used the vertex paint modifier and painted on top of my existing vertex colors. I still get a black render. 😞

Thanks!

wheel-fortroubleshoot-01.zip

[RGhost77]

wheel-fortroubleshoot-02.zip

It's works as expected. Please check attached scene.

p.s. In your scene you not assign Material #3 to the wheel, and Base color value must be 1.0 not 0.

[Anonymous]

OMG, thank you.

I guess I mistakenly changed the base color to zero while watching Mads' video, where he actually just changes the reflection to zero.

Thanks!!

[nintenjo64]

Sorry to jump on this old thread but i can get my Vertex colours to show in the viewport and in my renders (i was using the arnold User Data with channel uv_0) but the colors dont seem to match in the viewport (and on the mesh itself the colors are on the left) but in the render the colors seem to be in a different color space? Any idea? 

[nintenjo64]

Great video, but you dont show the vertex colours in the viewport..  As i suspect the colours your painting on the mesh dont match the colors you see in the render (at least thats the issue im having).