Camera's Depth Texture

Since Unity 2.6, a Camera can generate a depth or depth+normals texture. This is a minimalistic G-buffer texture that can be used for post-processing effects or to implement custom lighting models (e.g. light pre-pass). Camera actually builds the depth texture using Shader Replacement feature, so it's entirely possible to do that yourself, in case you need a different G-buffer setup.

Camera's depth texture can be turned on using Camera.depthTextureMode variable from script.

There are two possible depth texture modes:

• DepthTextureMode.Depth: a depth texture.
• DepthTextureMode.DepthNormals: depth and view space normals packed into one texture.

DepthTextureMode.Depth texture

This builds a screen-sized depth texture.

DepthTextureMode.DepthNormals texture

This builds a screen-sized 32 bit (8 bit/channel) texture, where view space normals are encoded into R&G channels, and depth is encoded in B&A channels. Normals are encoded using Stereographic projection, and depth is 16 bit value packed into two 8 bit channels.

UnityCG.cginc Cg include file has a helper function DecodeDepthNormal to decode depth and normal from the encoded pixel value. Returned depth is in 0..1 range.

For examples on how to use the depth and normals texture, please refer to the EdgeDetection image effect in the Shader Replacement example project or to the SSAOEffect in Pro Standard Assets.