How to keep showing 2D UI when doing 3D camera transition

[4everlove]

Hi,

I'm doing a cross fade transition between two 3D cameras, using RenderToTexture technique and change the alpha of texture. Meanwhile I need to keep showing an HUD no matter which 3D camera is active and whether under transition. However, I found 2D UI will also has a fade in effect when I do the cross fade. In my case, is there any way to not fade in 2D UI when transition happens?

Thanks!

[ArenMook]

Just do your render to texture before you draw your UI, like so:

3D camera -> renders to texture
2D camera -> draws the texture
2D camera -> draws the UI

[4everlove]

Thanks, Aren. I'm still little confused. I will do the RenderToTexture work in the middle of the game. How can I control the abovementioned sequence in my case?

[ArenMook]

Camera's depth controls the draw order.

[4everlove]

Thanks, I see. So according to your description, I need to use NGUI's 2D camera to draw the texture, am I right? Because right now, the 3D camera and 2D camera are in the right sequence, and I use Unity's own OnGUI function to do the fade in, such as

1. GUI.depth = -1; // 3D -2, 2D 0
2. GUI.color = new Color(…);
3. GUI.drawTexture(…);
4.  

And it does not work.

[ArenMook]

OnGUI is not NGUI. Don't confuse or mix the two. I also can't help you if you use Unity's GUI as it's not in any way related to NGUI.

Depth is specified on the Camera, not GUI.

[4everlove]

Hi, Aren. I'm sorry that I might not state the problems clearly. I do use NGUI except that I use OnGUI function only for the transition effect because I saw a code snippet showing this way. I use 3D cameras (with UICamera attached) for showing both 3D objects and 3D UI(pure NGUI widgets), while a 2D camera (with UICamera attached) shows persistent HUD(pure NGUI widgets as well). Now according to what you said, it seems I should use a 2D camera to draw the texture in between 3D camera and 2D camera and use the depth of camera to maintain the render sequence. Does that mean I need another 2D camera (with UICamera attached or not?)? And will you please show me some simple snippets to achieve this?

Thanks!

[ArenMook]

To display a texture on the screen (and this can be a RenderTexture as well), use UITexture (using the widget tool it's called "Simple Texture").