Variation texture @ component level

Foundry Modo (Developed by stenson, Integrated Plugin developed by Paul Kinnane)

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Dingbat
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in MODO the variation texture can be set up so that individual meshes in the same item can be varied - so e.g. if i have a tree with leaves, i can vary the colour of each leaf.

is there an equivalent Octane node or does the existing Octane variation node support multiple meshes in the same way?

AFAICT the Octane node only supports variation if the meshes are in separate items - is that the case?
Last edited by Dingbat on Fri Oct 23, 2020 4:10 pm, edited 1 time in total.
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face_off
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Hi

For Replicators (and potentially Instances), the plugin will assign an "Id" to each transform, so you should be able to use the Octane textures "Instance Color" and "Instance Range" to vary the texture of each instance/replication. You need to set the . I don't think these nodes will work with single Modo Mesh items.

3.07.0.125
- Added Instance Color and Instance Range textures
- Added an instance id to each Scatter transform (ie. each Replicator particle source will have a unqiue instance id). The Instance ID is sourced from the Modo Replicator source IDs. The new Texture node types Instance Range and Instance Color can be used with these id's. Refer to viewtopic.php?f=33&t=62395 for for details.

Paul
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funk
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The Octane core doesnt support anything like this (yet), so you have to use workarounds.

One way could be to use weight maps, and manually/procedurally/script the assignment of different weights per mesh "island". Then use the "greyscale vertex attribute" node as an input to a gradient for your colors.
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funk
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I have attached an example scene of 1 possible way to assign the random weight map values with meshops. It uses a "falloff operator" which has a confusingly named "Polygon Parts" output, which is actually MESH ISLANDS!

I then used Octanes greyscale vertex attribute node to get the weight map values and input to a gradient for the colors.
funk_random_colors_per_mesh_island.png
EDIT: If this is slow on heavy meshes like trees, you could just FREEZE the meshop, which will apply the weights to the mesh permanently.
Attachments
funk_random_colors_per_mesh_island.zip
(17.67 KiB) Downloaded 169 times
Win10 Pro / Ryzen 5950X / 128GB / RTX 4090 / MODO
"I am the resurrection, and the life: he that believeth in me, though he were dead, yet shall he live" - Jesus Christ
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funk
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Someone posted some questions about this setup on the modo forums:
https://community.foundry.com/discuss/t ... nent-level

Regarding the falloff operator:
Its just a single falloff split into 2 to make the schematic more readable.
In modo, you can add the "Polygon Part" channel by right clicking the falloff operator > add channel > Polygon Part.
You can then right click the Polygon part channel on the node > separate channel
Win10 Pro / Ryzen 5950X / 128GB / RTX 4090 / MODO
"I am the resurrection, and the life: he that believeth in me, though he were dead, yet shall he live" - Jesus Christ
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funk
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Greg made a video about this on Pixelfondue

Win10 Pro / Ryzen 5950X / 128GB / RTX 4090 / MODO
"I am the resurrection, and the life: he that believeth in me, though he were dead, yet shall he live" - Jesus Christ
Dingbat
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fantastic! thanks so much to both of you.

just need to figure out how to save efficiently for repeat use.
Dingbat
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icing on the cake would be a way to output the weight map as a render pass. is this possible?
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funk
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You could do a separate render, plugging the greyscale vertex attribute node into the diffuse channel of a material, then enable render passes > info passes > material diffuse filter.
Win10 Pro / Ryzen 5950X / 128GB / RTX 4090 / MODO
"I am the resurrection, and the life: he that believeth in me, though he were dead, yet shall he live" - Jesus Christ
Dingbat
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thanks - did something similar and it seems to work really well.

it also works on multiple items using the same name for the weight map so only needs one additional render with all the items plugged into the variation set up. easy enough to just unplug them when done.
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