Controls where particles are visible. For example, particles far away can be set to fade out, simulating fog. Here are also all obscuration settings that can beused to make layers in the composition obscure particles. There is also an option to use a Z buffer from another layer.
Far Vanish
The far distance from the camera when particles become completely invisible.
Far Start Fade
The far distance from the camera when particles start to fade out.
Near Start Fade
The near distance from the camera when particles start to fade out.
Near Vanish
The near distance from the camera when particles become completely invisible.
Near & Far Curves
The curve used to fade particles in the near and far fade zones. Can be linear or smooth.
Z Buffer
Select a 2D comp-sized lightness based linear Z Buffer layer here. A Z Buffer contains per-pixel depth values. It can be useful when particles are to be inserted into a scene from a 3D appliciation (like 3DS Max or Maya). The 3D app can be configured to output a Z Buffer (also know as Depth Buffer). The Z Buffer is not antialiased so it can look a bit rough on the object edges. In many cases this doesn't matter too much because particles are small and move fast.
Z at Black
Controls what depth (=distance to camera) a completely black pixel in the Z Buffer means.
Z at White
Controls what depth (=distance to camera) a completely white pixel in the Z Buffer means.
Obscuration Layer
Any 3D layer in the comp can be used to obscure particles. The obscuration layer cannot be a text layer, instead create the text in a comp and use that comp as obscuration layer. The obscuration layer must have "continous rasterize" switched off.
Place the obscuration layer below the particle-layer in the TLW. This obscuration is not antialiased so it can look a bit rough on the layer edges. In many cases this doesn't matter too much because particles are small and move fast.
View a step-by-step tutorial on using the Obscuration Layer.
Also Obscure With
The Layer Emitter, Wall and Floor can also be set up to obscure particles with this control. Make sure to place any layer that shall obscure particles below the particle layer in the TLW. This obscuration is not antialiased so it can look a bit rough on the layer edges. In many cases this doesn't matter too much because particles are small and move fast.