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Davide Bestetti avatar image
Davide Bestetti asked ·

randomizing MASH color node - rendering artifacts

Hi
I'm experimenting a few problems when trying to randomize colors of a MASH network in Maya, Arnold Render.
Trying to set up things with the Repromesh, although with the instancer utilizing an AiUtility instead of a AiUserDataColor everything works fine.

This is the Network i built so far:


Repromash with Aiopaque off (shader has Transmission @1), Export colorvertex on.
MASH color node with random value set to 1

This is what i see in my render view, certain pills render out incorrect, seems like a chromatic aberration on vertex..!!

Seems like this issue is connected to the MASHcolor.randomvalue, if i 0 it out, i get no more scatter of colours of course but i don't get anymore this problem.

Any advice?

renderarnoldmtoa
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Davide Bestetti avatar image
Davide Bestetti answered ·

Hi Lee
Utility is set to Object, it works in combo with the Instancer. I'm experimenting problems with the colors, but meh..

Repromesh with AiUserDataColor create the problem shown above. Noone of the modifications of the shader help fix it.

_____

I'm experimenting another problem (really?):

I added a Dynamic node, animated the number of point to have a linear spawn of pills along time.
The goal is to fill a glass with pills.
Problem is that after first pills simulation slows down (due to the amount of instanced obj i think) but the spawn does not.
The following video shows the problem:


https://youtu.be/o5DY9hyieoU


It is noticeable that the simulation runs in a totally different ways (more and more pills on the screen, but the spawn is linear).
Am i doing something wrong?
This is quite a simple simulation. Should i give up with MASH and jump to Houdini?

David

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Have you tried baking the simulation?

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I was not trying because i was wrongly sure that a stand in which is procedural would not have worked with the Utility node network.
I tested out and it works..it's not time to try the baking process!
Thanks Lee, i will update once done.

1 Like 1 · ·

Hi Lee

https://youtu.be/84hlh05AcQw

Caching the sim solved the main problem of "slowing down" new spawns, but:

I think the utility node is having problems with unique ID's for each new-spawn objects. (in this sim numberOfPoints of the distribute has been animated)
Tested out with a vertical column of 400 pills, problem is solved.




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Lee Griggs avatar image
Lee Griggs answered ·

Which color_mode is the utility set to?

Does changing any of the standard_surface attributes affect it? eg transmission_depth?

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