Table Of Contents
Redshift supports volumetric rendering. Currently the plugin supports the render OpenVDB files and the direct rendering of the Houdini Volume and VDB primitives. The plugin includes several options related to the volumetric rendering available in the RS OBJ spare parameters and the volume shader VOP node, that is used to control volumes shading.
Rendering OpenVDB Files
The rendering of OpenVDB files is done automatically from the File OBJ node. The plugin will extract the OpenVDB file path from the “file” parameter available in the File OBJ node. Redshift will load the OpenVDB file at render time using its internal OpenVDB loader, so the scene extraction time is really fast at this point.
Rendering Houdini Volume and VDB Primitives
The plugin can extract and render the volumetric data from the Houdini Volume and VDB primitives. You don’t need to convert them to VDB objects or save them to OpenVDB files. The plugin extracts automatically the volume data from Houdini if any volume grid primitive is detected inside the OBJ nodes. No further action is needed.
The volumetric shading is done using the RS Volume VOP node, linked to the ‘Volume’ pin in the RS output VOP. You need to set the grid names used for the density and emission channels, and configure the volume ramps and the other parameters available in this node.
You must set the volume material to be used for each volumetric object in the Material parameter of the OBJ node.
Redshift can instance the volume objects using the same instancing workflow used to instance geometric objects. If the first object to be instanced is a volume, the plugin will use the volume instancing functions automatically. Mix volume and geometry instances in the same instancer is not possible.
Volumetric Motion Blur. Velocity Grids
The plugin supports the extraction of the velocity grids from the Houdini Volume/VDB objects. The options to configure these grids and the velocity scale can be found in the RS OBJ spare parameters, volumes tab.