1. Build cache for OpenVDB
Set the EFX Format of the X-Particles cache tag to “OpenVDB”, open the subparameters, and turn on “Velocity” to build cache.
This is because Velocity data is required when applying motion blur to OpenVDB. Build cache takes a lot of time to calculate, so if you forgot it, it is necessary to be rebuilt, so be careful.
※It is not always necessary to build the cache, but in that case, add a Redshift volume material and assign it to the ExplosiaFX object. Also, the data to assign into each channel of the volume material must be ExplosiaFX.
2. Add Redshift Volume object
Add a Redshift volume object to your scene and set the path of the file for OpenVDB cache. If OpenVDB has animation, open the playback tab and click Detect Frames to load it as an animation.
You can adjust the number of points for the volume preview in the editor.
3. Add Velocity Grid to Motion blur settings
Set Velocity’s XYZ data in motion grid direction in the Redshift volume object. If the OpenVDB cache correctly contains Velocity data, vel_x, vel_y and vel_z are displayed in the Information area.
Next, it has to assgin redshift volume material.
4. Add Redshift volume material
Add Redshift volume material and set channel parameter from OpenVDB data.
5. Start rendering after turn on motion blur
Finally, turn on the Enabled for motion blur in the Render Settings and start rendering, but motion blur doesn’t work IPR rendering, you have to start final rendering (shift + R).