You can in fact control the Motion Blur being applied to particles on a per particle basis.
- Enable after DOF and output Velocities in the material.
- Then inside your Niagar System, change the Motion Blur settings to Approximate:
- Create a vector parameter, in my case I called it ‘MotionBlur’. Set it to Velocity * custom float (in my case a User Parameter).
- Replace the VelocityBinding in your Rendererer with the newly created MotionBlur parameter.
- You can then control the amount of MotionBlur being applied by adjusting the parameter.
However, I have found this give mixed results. Without motion Blur/Velocities being applied, small particles just get lost, visually. It’s a trade-off and just doesn’t quite work perfectly most of the time. It will also depend on your background, e.g. noisy background will give worse results than clear sky.
You can always try to set the MotionBlur to ‘Disable’ as well.
On a side note, the newly ‘After MotionBlur’ pass is useless 99% of the time. As partices draw in weird sorting order compared to the rest of the scene. Not sure what this is meant to be used for in practice.