Render To Texture

Render To Texture let you render scene to a texture, then reuse the texture for complex rendering like water, reflection, etc. 

Workflow:

1. Create a render target
Right-Click in the Texture Browse Window, select "Add Render Target" from the context menu. Then select a image file in Open File Dialog, the image size decide render resolution.

2. Select render target
There are two places where you can select render target: Shot Panel and Portal Panel.

For Shot, first set camera by shot's parameters, then rendering; if Shot has 'Not Affect Camera' style, use current camera for rendering.

For Portal, use current camera, then render scene contents that only can see through portal. If select render target in RTT(mirror), then first mirror scene by portal plane.

In the 'Render To Texture' rollout of the two panels:

you can:
1. Select render target from the top long button.
2. Assign whether draw overlays when rendering to texture.
3. Set a border for render target, border drawing use scene background color (see Viewport Options Dialog). 
4. Assign whether keep aspect ratio consistent with back buffer.
5. Do something before rendering / after rendering by setting actions.

3. Use render target as normal texture
Render target can be used as normal texture, for example,  you can assign it to a Image2D for test.