Depth Peeling

• A way to implement Front to Back Alpha Blending using a Graphics Pipeline .

How it works #

Render the whole scene in multiple rendering passes. As many rendering passes as Depth Complexity .

1. Render normal scene with standard depth test and store frame in RGBA texture

2. In the renderpass, render only the nearest fragments

   

3. At the end use the Alpha Blending computation to composite all the render targets together.

Determining if a fragment is eligible for the next closest layer #

Use two depth buffers, 2 depth tests per render pass.

1. Use the depth buffer from the last render pass, and discard every fragment that is closer than the last render pass.
2. Write all fragments in the current depth buffer and do normal depth buffering for all fragments that pass the first depth test.
3. Between render passes swap the buffers (“Ping-Pong Texture”).

Evaluation #

Con:

• As many rendering passes as Depth Complexity