2 cameras running the same time

http://forum.unity3d.com/threads/44911-2-cameras-running-the-same-time

1： 2个camera同时显示在一个屏幕里

It is certainly possible to have multiple cameras at once. There are a couple things to know that will help with this:

- Cameras have a "depth" property. This determines which order the cameras will draw. The camera with the highest depth will draw on top of the camera with the lowest.

- Clear Flags are important when dealing with multiple cameras. This basically says what to do with the empty space around whatever the camera is drawing. The foreground camera should be set to Depth Only. This will allow you to see the contents of the background camera.

- Culling masks are also useful. These allow you to control what content gets rendered with which camera via layers.

I hope that helps. Check out the camera page in the documentation for more info.

 

2： 做一个雷达类型的map，带小红点的用来显示自己和敌人的位置

I've done what you want on the iPhone like this....

1. With the gameobjects you want to appear on the "radar", each one needs to have a child gameobject that is something like a simple sphere. No colliders or physics on the sphere.

2. These spheres need to be assigned a unique tag... maybe name it "RadarViewOnly".

3. On the Main Camera (the camera that is used for your regular game play), change the culling property to NOT include "RadarViewOnly".

4. Now position a new Camera (the radar camera) up high, directly above the Main Camera, and have it looking straight down. Set this camera's culling property to ONLY include "RadarViewOnly". And set the clear flag to Depth Only.

5. If you want the radar view to seem to appear in a window. You should place a 2d plane, with the a texture that you want to use as the window, as a child of the radar camera, set it's tag to "RadarViewOnly", and have it positioned facing the radar camera and far away.

3：多个camera view在分上下在同一个windows下现在

http://answers.unity3d.com/questions/10206/how-can-i-show-split-screen-or-multiple-camera-vie.html

 

RenderTexture looks like a powerful tool, but can't this just be done with an extra camera limited to the top right corner of the screen?

Create another camera. In the inspector take a look at "Normalized View Port Rect", and change the values to this:
X: 0.7 Y:0.7 W:0.3 H:0.3 This will place the new camera window on the top right of the screen.

Make sure you remove the component Audio Listener from the new camera, as there should be only one in a scene.

Correct me if I'm wrong, I'm still a beginner with this Unity stuff