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didi chen avatar image
didi chen asked ·

How to set the shading mode of rampRGB to 3D Linear?

In Cinema4D's standard materials I can add a gradient and set the type to "3D Linear" which gives a nice colored flow effect when the object is distorted.

In C4DtoA's rampRGB I can't find the 3D projection option. I have tried adding uv projection, uv transform or Triplanar, but it doesn't work.

How can I achieve a 3D Linear gradient in Arnold?

uvramp
screenshot.jpg (150.1 KiB)
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T W avatar image
T W answered ·

my bad, its working now . . thanks

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T W avatar image
T W answered ·

any chance you could re upload this file, please.

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Peter Horvath avatar image
Peter Horvath answered ·

We don't have the 3D modes built in to our ramp shader, but you can build a shader network using the shading point position (Po in state_vector shader) to replicate the 3D gradient.

Here's a setup for 3D Spherical and 3D linear: 3d_gradient.zip

In 3D linear you have to project the shading point to the line defined by the Start and End values of the gradient, which could be a bit complex as a shader network. If you just need to move along one axis (e.g. only X), then you can end up with a much simpler network using a range shader.


3d-gradient.zip (253.1 KiB)
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Thanks for the answer.

But there are some other questions: how to adjust the orientation of the gradient texture itself in this way, and how to change the uv scale, the tiling method, and other parameters?

The uv projection and uv transform nodes don't seem to work.

p.s. The Arnold material node used to implement the 3d linear gradient is just too complicated. I hope the 3d linear projection method could be one of the items on the list of gradient properties, like the gradient effect in Cinema4D standard materials.

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3D gradients depend on the distance not the UVs, that's why UV modifications have no effect. Or is it possible in C4D? Can you show me the setup and look you are looking for?

I agree, it would be nice to have this modes directly in the ramp shader. We have to discuss this internally.

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With your help, I've implemented the 3d linear gradient with some nodes, but the gradient texture is currently not tiled, which is still a problem I can't solve.

Here is download link of relevant files:https://cowtransfer.com/s/4a95fd922ff14b

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