Polymesh objects can be rendered as volumes. This gives many creative opportunities for rendering solid objects in varied and interesting ways. This short 'making of' tutorial shows how to combine a polymesh with a volume by combining their shading using the displacement attribute of a standard_volume shader. We will also cover how to reproduce the above-animated effect using the cell_noise, color_correct, ramp_rgb and range shaders connected to volume_displacement of the standard_volume shader. An example of a free to use head scan model can be found here. The polymesh should be closed and not have anything self-intersecting, otherwise, the volume may not render correctly. More information about volume step_size can be found here.Step Size
Head mesh rendered as volume To animate the effect from top to bottom we will project a ramp through the V direction. Create a camera_projection shader and connect it to the input of the range shader. Remember to select the render camera that you want to use for the camera_projection. Final cell_noise settingsStandard Volume
Range
Camera Projection
Ramp RGB
Color Correct
Cell Noise
Animation
- Keyframe the black color of the ramp_rgb from left to right over time to see the effect move bottom to top across the head volume.
- Keyframe the time attribute of the cell_noise shader to animate the cell_noise effect.
Conclusion
That's it. Remember to increase the volume_samples for any lights in the scene when rendering the final animation. Further example with cell_noise scaled in Y