Octane - Scattering Features Tweet

[AaronWestwood]

6. Source proximity color: You can get the instance position in a projection node and use it to sample a procedural 3D texture.

Heya. Just wondering if you could go into further detail re this point? Very curious as if was already possible that would be huge.

[jobigoud]

Based on the original text:

6. Source proximity coloura data. Grass comes to mind, setup a ground diffuse map with various green and brown gradients and have the scattered grass on top be able to read this colour info and adopt that colour variation for a huge step in realism. You can do this through a very slow shader system in C4D but again, having this as an option in the the scatter would be amazing. Would help for blending assets to the ground plane also.

I attach a sample ocs file for Octane standalone 2022 XB1 using the instance position projection.
Using a noise texture to define values, each instance is assigned one and only one value. Then I plug this into a gradient map in constant mode to assign a specific color/texture to each instance. (compare with not using the projection, the 3D texture is applied globally so some instances are crossed by a color boundary).

I don't know if this covers what you wanted to do. Note that the texture has to be procedural as the instance position is an arbitrary point in 3D. If the ground texture is itself a 3D texture and the instances have their origin at the point where they meet the ground this should work for transferring the local ground color to instances.

To make this work with an image, like a biome map for example, we need to use the object selection map (currently limited to 4 objects in standalone).

demo-instance-position.ocs

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