Motion Blur Fluid Source Particles

[evanrudefx]

Hey!

I am trying to use particles as a source for pyro. For some reason the motion blur (from fluid source node) is not working as it should. I added a trail sop (to see what it would look like) and I am getting weird results. The first photo is with out the trail sop. Next photo is with it on. Clearly something is not right. You can see the same effect by viewing fuel as a slice and blurring it. What am I doing wrong? The particles were cached with velocity attribute. I also included the scene.

thanks

particleblur.zip

[Dam]

If it's still off, I would try to turn on (Geometry Velocity Blur) on the GEO node under the sampling tab and (allow motion blur) under the rendering tab of your mantra node.

Edited August 31, 2017 by Dam

[macj89]

Be sure this two guys are ON before rendering:

 

 

[Sierra62]

The enabling Geometry Velocity blur is only relevant for rendering.   The issue here has more to do with the fluid stamping particles.  Personally I have had inconsistent results with using the fluid source motion blur on particles.  I suspect it has to do with the changing point count and not having control over what attribute to use, such as id.  The motion blur works much better on actual geometry.    There are some issues that are worth noting when using the fluid source motion blur, the main issue is that it doesn't blur the velocity channel as well.  So you can end up with a nice looking density source, but the velocity looks the same as density without motion blur.

Typically when I am doing something fast moving and I won't use the motion blur on the fluid source, I prefer to use a trail with the "preserve original" result.  This gives me more control over the trail look, and I don't have to deal with lack of velocity blur when I use the fluid source node.

 

[evanrudefx]

I didnt realize this thread had re-opened.  I already figured out how to do it. Throw in a timeblend sop before the trail sop. Gives correct particle trails