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Pedro Martinez Martinez avatar image
Pedro Martinez Martinez asked ·

MAYA. SHADOWS PASS WITH TRACESETS

Hi all, recurrent problem setting shadow pass. I'm breaking my scene into different render setup layers (characters, background, shadows, etc). In the shadow pass I only need characters shadows over background, so:
.- Character geos with CHAR in Trace Sets property (shapes). The Sphere in this case.

.- Background geos with SET in Trace Sets property (shapes). The planes in this case.

.- Shadow matte shader --> TraceSet --> raySwitch assigned to background objects (same network as scene in manual https://docs.arnoldrenderer.com/display/A5AFMUG/Trace+Set).

.- Trace Set node in above network, CHAR inclusive ( to avoid shadow rays from SET geometries). Inverting values (SET exclusive) throws same result.

The result shown is shadow AOV.

In the caption, the shadow marked with "V" is the searched result, shadow from ball (CHAR).

The "Shadow" marked with "X", I dont know what it is, because its not the shadow from top plane into down plane. I SUPPOSE it's the ball shadow projected onto down plane, but ... all planes cast shadows, so I SUPPOSE that's a collateral effect from Trace Set shader.

The big question is, can we stop the shadow marked with "X" to not appear?

Yes, I know that in this scene is easy but, in production scenes where are hundreds of objects and lights, can we setup globally the scene without working objects one by one?

Thanks in advance !!!sombra.png

mtoashadowstraceset
sombra.png (207.5 KiB)
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Pedro Martinez Martinez avatar image
Pedro Martinez Martinez answered ·

Thanks for that quick reply! It's difficult to explain this situation. The problem is not the "by object setup", let me explain it.

The problem is, the shadows are crossing geometric that they shouldn't. In the capture of the original post, for example, the sphere could be a character on a table (the upper plane), and the shadow of the character is being projected on the table but also on the floor, these two objects are inside of the same category (background).

The problem is not to treat each object and assign a traceset to it, but to discern in each case who should receive shadows and who should not within the background.

To get an idea, if in this situation, character on table and table on floor, we configure the traceset so that the ground does not receive the shadow of the character, and the character jumps off the table and falls to the ground, that setup will no longer work.

The question is, I think, why is the shadow going through the upper plane, and if there is any way to fix it, or if I am doing something wrong.

I'm sorry to explain myself so badly ...

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Lee Griggs avatar image
Lee Griggs answered ·

>can we setup globally the scene without working objects one by one?

Have you tried override sets?

1614167954912.png


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