Table of contents:
To modify the appearance settings of a volume rendered dataset, simply select the object in the scene / scene hierarchy - and you will find the appearance settings under "Volume Rendered Object" in the inspector.
There are 3 render modes:
- Direct Volume Rendering (raymarching, using transfer functions)
- Maximum Intensity Projection (shows the maximum density)
- Isosurface Rendering (raymarching, stops when it hits a surface)
You can enable lighting to get more realistic visualisation.
This comes at a cost, and performance may suffer (both memory and rendering speed).
To apply lighting to the volume rendering, we calculate the gradient at each voxel and use this to calculate a normal, which we use to apply phong lighting.
Improve the rendered image by using shadow volumes. This is expensive, but there are ways to still get good performance with this enabled. See shadow volume documentation
To reduce so-called "staircase artifacts", you can enable cubic interpolation.
This can be quite expensive in terms of performance - especially when lighting is enabled!
To improve performance, the raymarching shader may optionally exit early when enough samples have been accumulated. This is a very simple optimisation that improves performance by avoiding enumeration of invisible voxels.
You usually want to leave this setting enabled, since it improves performance considerably - usually without any noticable visual changes.