Color by particles/replicator

[Flyx]

Hi,

Is it possible for octane to access the color info of the replicator to color each instance individualy ?

Like this setup in the modo render, as you can see the linear falloff drive the blue color this is what i would like to be able to replicate.
Something like the mograph shader on C4D, wich is usable with octane plugin.

Thanks !

[face_off]

Hi - I think Mograph is using a world space projection to achieve this. So in Modo, add an Image to the Prototype Mesh shader, then add an Octane Override to the same material group and set the Projection of the Image to Box, World Space.

Paul

[Flyx]

Hi ,actually mograph use the real color info on each object, not just a map.
The mograph shader is just a way to use these info in a real shader.

I'm trying to achieve the same thing, to be able to control color directly with modo falloff object (and not map or wathever) using the particles color info.

As you can see in this scene file, the cube's color are driven by the particles modifier and corresponding falloff, wich give more freedom and easier control.
Modo extract the color info of the instance with the shader inputs node.

[face_off]

Hi ,actually mograph use the real color info on each object, not just a map.

Can you pls send me an ORBX exported from the C4D plugin which uses the Mograph shader in the way you want to use it in Modo?

Paul

[Flyx]

Sadly i don't own a C4D octane license, all i know is that it work's this way with redshift and i've seen video of people doing that kind of thing with octane too, controlling the color/emission directly with mograph effector and falloff without the use of map.

Maybe someone here with octane and C4D can make that file for you.

My guess is that it can do this because the cloner (some kind replicator equivalent) or whatever you want in C4D doesn't treat object as instance at first, so he's allowed to adjust parameters on each one independently, and so octane get the color attribute somewhere at render time and then create temporary copy of the material, change the color where there is that mograph shader and then apply it.

All of this of course is purely theoretical, and could be a nightmare to implement....but if they can do this on another software, maybe we can on modo too

[Flyx]

Hi

Any news ?
Were you able to take a look at this problem ?

Thanks !

[face_off]

Sorry - I need an ORBX as requested above to progress this issue.

Paul

[Flyx]

I'm sorry and don't want to sound rude but we are on the modo forum, i'm asking something about a modo functionnality and you are the modo plugin dev.
You can't ask me a file coming from C4D without event having a look at the setup and the way modo handles this kind of thing.

Maybe you could directly ask the C4D dev about this, you have contact between the octane devs no ? It's not my part of the job to do such things.

Don't get me wrong, i respect you and your work, octane is a good renderer and you are doing quite a good job porting it to modo, i'm just tired seeing so much forgotten promise, half implemented things and false information all over the octane world.
And as english is not my langage it's hard to explain things diplomatically !

[face_off]

Modo Replicators translate directly to an Octane Scatter node - so in the situation you have described, there is a single cube which is the source of an Octane Scatter node with 100 transforms (being the cubes in the grid pattern). Octane provides no direct way to change the material of specific instances so all 100 cubes will have the same material. So the only way to change the diffuse color of specific cube instances is to use a texturemap with the UV Projection changed to Box and the project changes to have the projected image cover the extent of the cubes. This is the approach I suggested earlier in this thread.

Paul

[Flyx]

Yes i understand this workaround, but it will work only on simple pattern, if i want to animate the falloff, wich is the point here, on more complex pattern it will become not really viable as we would nedd to bake the color animation each time we change one thing :/
That's why i would like to be able to use this workflow, wich is a legit one not some modo under the hood crazy unstable setup^^

So if there is no way to control color independantly on a scatter node, can we take it the other way, treat the replicator as render time with an option like don't render as instance and make the plugin create real copy, and get the color automaticaly from the shader Inputs node ?
I know for large replicator system it will increase a lot the processing time, but with simplier mesh and reasonnable number of copy it could work without filling all the gpu's memory.

I'm ok if there is a modo or octane limitation, but i just want to know it and why, i'm the kind of guy who like technical precision and not just 'it won't work'

PS: i swear i'm a nice guy don't take my posts too badly !