Matte Objects

[lordpazuzu]

Hi!!

First of all! Amazing work on the plugin, thank you very much for the effort!!

It will be very nice if we can have a matte option that can just hold out the scene; Right now the matte option serves as a shadow catcher, so is not possible to just hold out because my alpha channel will have the shadow information also and there will be some overhead because of the shadow computation over the matte object. So currently my approach is to do two renders, one with the shadow catcher and another with the shadows turn off for my original object to get a clean alpha channel and with the hold out.

Thank you!

[juanjgon]

I hope that these kind features can easily be added once we have the OSL support in place to write our own custom shader nodes.

-Juanjo

[lordpazuzu]

Awesome!!
Thank you!

[abstrax]

You would use the render layers together with shadow passes for exactly that.

[juanjgon]

You would use the render layers together with shadow passes for exactly that.

Yes, true. You can check the docs about this topic:
https://docs.otoy.com/Houdini/?page_id=1161

-Juanjo

[lordpazuzu]

It works perfect! Thank you!

[ptunstall]

I am trying to get this result aswell with volumes so I can just over my smoke on top of my render but I seem to not understand the workflow. How do I just get the alpha of the smoke without the shadow of the other geometry adding anything?

[fantome]

i would be curious to know if there are progress, on this topic ?
are we now able to render a proper matte object inside octane.
so for exemple i have :
- a mesh of a CG ocean
- a volumetric foam
- a particle spray sim of the foam

but i would like to separate them in comp. so is there a way to properly set the ocean geo as a matte object, where it will have absolutely no influence in the scene lighting in direct and indirect illum.
Thus i will be able to get my particles and my foam matted by this ocean geo, but with no visibility of it in the alpha channel.

Cheers

[juanjgon]

I think that the layers rendering is probably the best workflow for this kind of project.

-Juanjo

[fantome]

thanks for your answer Juanjo. direct matte object support like in RS would be great, but it's a standalone limitation, not a pluggin one.