Greetings,

I want to create a rapid pyro explosion. For this, I modified some normals on a sphere and used them to drive the velocity of my particles. Im then converting the particles to VDB, thereby extracting vel for use in my pyro sim.

The problem is the strange behaviour of the velocity trail in the VDB from particles node. Im not sure if this is a common issue. As you can see in the screenshot the particles are only emitting on one side. This seems to be somehow related to the Velocity Multiplier, but with my limited experience I cant seem to fix it.

Let me know what can be done to fix this.

Thanks!

Yep, that's broken. Submit that file to support@sidefx.com. You have found a bug.

You're visualizing a velocity (vector) field as density, of course it looks like that. Negative values are not normally visible. To visualize a vector field, use a different tool such as a slice or trail.

jsmack
You're visualizing a velocity (vector) field as density, of course it looks like that. Negative values are not normally visible. To visualize a vector field, use a different tool such as a slice or trail.

Thanks for letting me know. So this is displaying correctly? Should I still submit it as a bug as Enivob mentioned?

Icantbecuz

jsmack
You're visualizing a velocity (vector) field as density, of course it looks like that. Negative values are not normally visible. To visualize a vector field, use a different tool such as a slice or trail.

Thanks for letting me know. So this is displaying correctly? Should I still submit it as a bug as Enivob mentioned?

Yes, this is displaying correctly. You could add a primitive sop to make the velocity field invisible if it is getting in the way.