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Can Shadow Matte AOVs be achieved on a per-light basis? Or even by Light Group?

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Message 1 of 12
chadGE3G6
833 Views, 11 Replies

Can Shadow Matte AOVs be achieved on a per-light basis? Or even by Light Group?

 
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11 REPLIES 11
Message 2 of 12
Stephen.Blair
in reply to: chadGE3G6

No, you can't do that with current shadow matte shader. We need to implement a version of the shader that uses closures, so that then you can use LPEs with it.



// Stephen Blair
// Arnold Renderer Support
Message 3 of 12
chadGE3G6
in reply to: chadGE3G6

That would be fantastic and powerful. Thanks!

Message 4 of 12
Anonymous
in reply to: chadGE3G6

Is this still true for version 5.1.0.1 ?

Thank you,

Message 5 of 12
Stephen.Blair
in reply to: Anonymous

@Jim Polk As of Arnold 5.1, you can get the shadow matte for a specific light.

Per-lightgroup shadow mattes: The shadow_matte shader has a new aov_group parameter that when enabled makes the shader sensitive only to lights with a matching aov setting.

In MtoA, shadow matte has a Light Group box that restricts the shadow matte to a single light.

4045-shadow-matte-light-group.jpg



// Stephen Blair
// Arnold Renderer Support
Message 6 of 12
hitecom8172
in reply to: chadGE3G6

so lpe's are theoretically possible.

Message 7 of 12
Stephen.Blair
in reply to: hitecom8172

No, that's not done with LPEs



// Stephen Blair
// Arnold Renderer Support
Message 8 of 12
Anonymous
in reply to: Stephen.Blair

Hi Stephen, Apologies for my late reply,..

We only use Maya for modelling not for lighting or lookdev..

We use Crom, an in-house program that's like Katana,etc., and create our own assfiles

using the Arnold Python API. Would you be so kind as to re-express your answer in

those terms?

Thank you very much,

Jim

Message 9 of 12
Anonymous
in reply to: Anonymous

Just to add...if you have any actual assfiles that show how things are connected that would especially helpful. Ty!

Message 10 of 12
Anonymous
in reply to: chadGE3G6


Just to add..
In Arnold 4, we created an EXR composed of what we call 'castshad' layers, one for each light in the scene.

Each of these layers shows *all* of the shadows for *all* objects for *that* light.

The geometry objects are assigned a grey shader, in A5 it's something like:

standard_surface
{
name TrackManGeom
base 1
base_color 0.5 0.5 0.5
}

Each light's block in the assfile fills the 'aov' param with something like 'key1Light',etc.


From your earlier answer, I understand that the shadow_matte block should be configured like:

shadow_matte
{
name thisMatte
aov_group 'key1Light'
}

But what I'm not getting is the relationship between the standard_surface block and the shadow_matte block.
Thank you,

Message 11 of 12
Stephen.Blair
in reply to: Anonymous

@Jim Polk

You just have to set the shadow_matte.aov_group parameter with a string value that matches the shadow-matte-aov-group-test.ass parameter of one or more lights.

An example ass file is attached.



// Stephen Blair
// Arnold Renderer Support
Message 12 of 12
Anonymous
in reply to: Anonymous

Awesome! I'll study this, Thank you!!

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