Trouble with Data test operator

#1

Hi everyone,

Today I setup a simple scene that spawns particles from an object’s surface. Then I apply an animated gradient ramp map to object so that I can use Data Test Operator to send particles from white parts of object’ surface to second event.

To render the second event only, I add a Render Operator to the first event and set it to None. Then I play animation on viewport and everything shows exactly what I imagined.

But when I hit render one frame to test, no particle is rendered. I look back to the viewport and see that all particles are disappeared. And they never come back even when I turn off the Render Operator or Data Test Operator or both.

I used only 2 mils of particles while my PC can render up to 65 mils.

Do you guys meet that trouble before? Hope you can help.

Thanks

#2

If you only want to render specific events the best way is to remove the Render Op from the PF Source Event and add a Render Op to all Events you want to render.

As for your particles disappearing in the viewport, that sounds like the yet unresolved first event spawning issue. Just toggle the system off and back on again using the “;” semi-colon key or the Light Bulb Icon in the PF Source, your particles should come back.

#3

Thanks Johny :smiley:

When the particles disappeared, I couldnt make them come back, although I had switch the PFlow on/off many times. I had to cached particles to disk then load them by Krakatoa PRT Loader to solve this. And it takes half of day to cache although I just spawn 3 mils particles.

This problem comes to me in this scene only. So I think it’s because of the calculating of Data Test operator.

#4

Maps and Materials operations are super slow in PFlow. :sad: No real way around it other than not using them.