Jump to content
Sign in to follow this  
haggi

Inherit Velocity With Particles

Recommended Posts

I'm just playing around with the particles.

I emit particles from an movin sphere. I want the particles to inherit the velocity of the sphere.

This works if I set the emission type to points. The effect dissappears immedialty if I switch to

surface(random) emission type.

Can anyone explain why this happens?

Thanks a lot.

Share this post


Link to post
Share on other sites
I'm just playing around with the particles.

I emit particles from an movin sphere. I want the particles to inherit the velocity of the sphere.

This works if I set the emission type to points. The effect dissappears immedialty if I switch to

surface(random) emission type.

Can anyone explain why this happens?

Thanks a lot.

Has the sphere a velocity (v) attribute? It should work.

Share this post


Link to post
Share on other sites

If the sphere doesn't have a velocity, try putting down a Trail SOP right before the sphere goes into the POP Networks. In the Trail SOP, select the trail type to be "Compute Velocity". And presto - your sphere will have a velocity attribute, and by default, your Source POP will (should) inherit the velocity of the sphere.

Share this post


Link to post
Share on other sites
I'm just playing around with the particles.

I emit particles from an movin sphere. I want the particles to inherit the velocity of the sphere.

This works if I set the emission type to points. The effect dissappears immedialty if I switch to

surface(random) emission type.

Can anyone explain why this happens?

Thanks a lot.

What do you mean by disappear? The particles? Or, do they just birth from the surface position without velocity? To reiterate, you are using the trail sop to compute velocity prior to the popnet, right?

Share this post


Link to post
Share on other sites

Okay, thanks for the answeres. Unfortunatly I didnt succeed yet.

This is my setup:

- A sphere with a simple animation in x direction.

- below the sphere a grid

- the sphere emits particles

- the particles have a force for gravity

- the grid is a collision object for the particles

Then I added a trail sop to my sphere before feeding into the popnet. With the default settings of the particle source emission type "Points (random)" everything works fine, the velocity is inherited. But I want the particeles to be generated from the surface of my sphere. To do so I switch the emission type from "points (random)" to "Surface (random)". Now the velocity is suddently ignored.

I added two images, the first shows the simple scene setup and the other one the particle network. I hope you can see what I mean.

post-3146-1192307978_thumb.jpg

post-3146-1192308000_thumb.jpg

Share this post


Link to post
Share on other sites

here is a quick example that i did and it all seems to work fine. If you post your scene, it would be easier to see what is going on. The only thing I can think of is to make sure your sphere is a poly/mesh/nurbs surface, not a primitive.

inheritTest_001.hip

Edited by SpencerL

Share this post


Link to post
Share on other sites
The only thing I can think of is to make sure your sphere is a poly/mesh/nurbs surface, not a primitive.

That was it! I used a primitive the whole time.

Thank you for sharing your thoughts :)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×