Live 2022.09.04

Solaris Karma MaterialX Surface Shader Blending

Scene File

Download 2022_09_02_karma_particle_basics.hiplc

Summary

To quickly produce a nice looking particle cloud shape, I move points through a noise function. This can be done iteratively, in a for-loop to create detailed wisps. You can also experiment with settings such as roughness or frequency and see the results quickly. This is a nice alternative to simulating particles which can be more time consuming process involving caching many frames to memory or disk. Below is an animation showing the evolution of the particle form as various noise settings are adjusted.

Shader Details

The final shader uses the standard surface with diffuse, specular, SSS, thin-walled and opacity.

The colors are also controlled in the shader. We start with the color attribute, which is the relative bounding box position of the particles before they're shifted through the noise in this case. This attribute is then fed through a noise function and finally a ramp. This allows for quick adjustments to be made all in the shader manipulating distribution of the final color output. This color output is used to drive the diffuse and SSS components of the surface shader. This gives a nice semi-translucent look to the particles.

Video On Demand

• 02:35 Importing the MaterialX Shaderball
• 03:59 MaterialX online viewer https://academysoftwarefoundation.github.io/MaterialX/
• 05:51 Importing the shaderball into Solaris
• 06:38 Viewing the Solaris scene graph tree
• 10:10 Using materials from https://ambientcg.com/
• 23:05 Autodesk Standard Surface Documentation
• 25:45 Duplicating geometry
• 28:00 Editing a material MaterialX graph
• 35:10 Importing the marble material
• 39:17 Edit material properties LOP
• 43:30 Editing the marble shading network
• 53:00 Mixing surface nodes
• 58:00 Using spatial noise to mix surfaces
• 1:11:00 usdz files
• 1:14:00 Wrapping up, stream topics overview

Additional Images