How do I clear a specific render target when more than one are set? Or how do I keep the depth but clear the color?

Question

Let's say I set two render targets

GraphicsDevice.SetRenderTargets(rt0, rt1);

If I call

GraphicsDevice.Clear(Color.Transparent);

both render targets will be cleared.

Therefore, how can I clear a render target at a specific index? For example just 'rt1' and not 'rt0'.

I would like to avoid texture baking the contents of 'rt0' to another render target and copying them back to 'rt0'. This is because PreserveContents on the XBOX 360 can only hold one render target in memory.

EDIT:

Is there any way just clear the color for a render target? I would like to keep the depth for depth reading.

Answer 1

To clear a specific render target you can either call SetRenderTarget() with only the one you want to clear, or use a pixel shader that outputs an opaque colour to one target and transparent to the other.

To avoid clearing depth use GraphicsDevice.Clear(ClearOptions.Target, Color.Transparent, 0.0f, 0);