Density by texture

[trivisor]

Hello Friends,
I've problems to birth particles based on a texture map which is used in the diffuse slot.

I built a simple Setup:

A box with a base V-Ray Material. The only Map of this material is a checker map in the diffuse channel.

TyFlow:

A simple birth operator.
Next a position object operator (see attachement)

That's it!
But unfortunately no particles are generated.
I changed the checker to a gradient ramp with the same result.

What am I doing wrong?

Thank you for help!

[tyFlow]

It seems VRayMtl exposes the diffuse texture in slot 0 (instead of slot 1)...switch mode to 'ambient' and it should work.

Standard Material, Physical Material, etc...all expose diffuse in slot 1...so this appears to be a VRay idiosyncrasy.

[trivisor]

Hello Admin,
thank you for your reply.
Maybe I'm wrong, but the result of the ambient channel doesn't fit to the map. (see attachments)
As it appears, the particles refer to the density of the mesh since nose, eyes and ears are more dense than the rest of the mesh.

Is there any help?            

[tyFlow]

Can you post your file?

[trivisor]

of course!

[tyFlow]

You enabled "position as UVW" in your Position Object settings - you definitely don't want to have that enabled in your setup.

And in your material editor, the checker material (map #35) has it's mapping source set to 'vertex color channel' instead of 'explicit map channel'.

[trivisor]

You enabled "position as UVW" in your Position Object settings - you definitely don't want to have that enabled in your setup.

And in your material editor, the checker material (map #35) has it's mapping source set to 'vertex color channel' instead of 'explicit map channel'.

Yes it works now.
Thank you for your help!