Visibility group

The Visibility group controls where particles are visible in the composition. For example, particles far away can be set to fade out, which is great for simulating fog. There is also an option to use a Z buffer from another layer, which lets you control the match the visibility depth to an animation or image rendered in a 3D program. The Visibility section also holds the Obscuration settings that can be used to make layers obscure the particles.

At left, the full Visibility group. At right, a diagram of how Visibility works in Particular.

Far Vanish

The Far Vanish value set the distance from the camera when particles become completely invisible. Low values mean the particles become invisible relatively close to the camera. High values assure that the particles remain visible even if very distant from the camera.

With Far Vanish set to a low value, the snow particles appear to have little depth.

With Far Vanish set to a high value, the snow particles appear to have a lot of depth.

Far Start Fade

The Fart Start Fade set the distance from the camera when particles start to fade out or become transparent before they disappear at the Far Vanish point. Low values will make the particles start to fade relatively close to the camera. High values keep the particles from fading until they get close to the Far Vanish distance. Note that the Far Start Fade should be less than the Far Vanish value or the particles will not appear to fade out but simply disappear.

With Far Start Fade set to a low value particles look semi-transparent even close to the camera.

With Far Start Fade set to a high value even distant particles are visible in the scene.

Near Start Fade

This control set the near distance from the camera where particles start to fade out. The default value is 10, making only particles very close to the camera become semi-transparent. Higher values make the fade begin farther from the camera likely causing more particles to render with some transparency.

The Near Start Fade set a low value make most particles in the scene visible.

With a high value for Near Start Fade, many particles appear partially transparent.

Near Vanish

This control set the near distance from the camera when particles become completely invisible. The default value is one, making nearly all particles in the scene at least somewhat visible. Higher values mean the particles must be farther away from the camera to be invisible in the scene. Note that Near Vanish should always be less that Near Start Fade, otherwise particles will simply appear to instantly disappear as they approach the camera.

Left to right, Near Vanish set low and high.

Near and Far Curves

This menu lets you set the curve used to fade particles in the Near and Far Fade zones. This option are Linear or Smooth.

Z Buffer

The Z Buffer menu lets you select a 2D, comp-sized, lightness-based, linear layer to use as a Z-buffer.

A Z-buffer contains per-pixel depth values, where black is the farthest point from the camera and white pixels are the closest pixels to the camera. Gray values in between represent intermediate distances. Typically, Z-buffering stores the Z-axis value of each pixel relative to a camera and is generally output from a 3D modeling and animation application like Autodesk 3D Studio Max, Maya or other 3D tools like Cinema 4D or Modo.

Z-buffering can be useful when particles are to be inserted into a scene that has been rendered in a 3D modeling application. The 3D application can be configured to output a Z Buffer (also known as Depth Buffer) when rendering the 3D scene. The Z Buffer image is not anti-aliased so its effect can look a bit rough on the object edges. In many cases, this issue doesn't matter because the particles are small and move relatively quickly compared to the animation or objects in the original 3D content.

Specify a layer for the Z Buffer.

Z at Black

Particular reads the Z buffer contents but it cannot determine how the black pixels in the image correspond to the Far Vanish distance without a user input to give a scale. By default, this value is to 20,000 but you can use values that correspond to real units if you have calculated those in your 3D modeling application.

Z at White

Particular reads the Z buffer contents but it cannot determine how the white pixels in the image correspond to the Near Vanish distance without a user input to give a scale. By default, this value is to 0 but you can use values that correspond to real units if you have calculated those in your 3D modeling application.

Obscuration Layer, Also Obscure With

Since Trapcode Particular is applied to a 2D layer and the particles live in their own 3D world, other layers in the composition won't automatically obscure the particles. The Obscuration Layer provides a way to insert a 3D layer into the particles' world that will obscure the visibility of the particles. Also Obscures With can additionally tell the Layer Emitter, Wall and Floor to obscure particles. Read more about using the Obscuration Layer.

The two Obscuration layer options in Particular