You can bounce a particle stream off either an image or a bouncer. When particles bounce off an image, they bounce off the surface wherever its matte is white or grey. Particles only pass through the areas of the image where its matte is pure black. If a surface's matte is turned off, particles bounce off the entire surface.
When you use a bouncer, it must be the parent of an axis or a light source. A bouncer shows up as a sphere in the Action scene when you use it with a light source. Otherwise, all other types of surfaces create flat bouncers.
Whether you use a bouncer or an image, bouncing particles are controlled using the Particle Bouncer menu.
(a) Bounce Type box
Select: | To: |
---|---|
Bounce | Bounce particles off images or bouncers. All bounce properties work with this type of bounce behaviour. |
Extinct | Make particles disappear when they reach a surface. Only the Max Dist parameter works with this type of bounce. |
Generator | Create an additional particle stream when particles bounce. When using this bouncing behaviour, you must add another particle generator. See Combining Particle Streams. |
Generator+ Extinct | Make particles disappear and create an additional particle stream when particles reach a parented surface. Only the Max Dist parameter works with this type of bounce unless the particles end in another particle stream. See Combining Particle Streams. |
Because an image is only a pixel in width, it is unlikely that fast moving particles will hit the image directly. Max Dist acts like a buffer zone after the surface. If particles fall through the surface, set the Max Dist to -100. Particles that miss the surface by 100 pixels will still bounce.
If particles still fall through the surface, increase the timestep to increase the accuracy of the particle stream.