Texture UV

UI
1

Hi guys,

I’m currently working on my first Unity project, but not my first game, and I’m figuring out how to do 2D interface. So far I find it quite easy even thought its kinda different from others engine I’ve used.

In other project, we used Texture Atlas to optimize performance, using less video memory, etc. I want to do the same here but I found out there is no quick and simple UseTexture(Texture myTex,Rect uvs).

Of course I was able to get this to work by doing this :

mSliderBack = new Texture2D(192, 40, TextureFormat.ARGB32, false);
        mSliderBack.SetPixels(mAtlas.GetPixels(0, 216, 192, 40));
        mSliderBack.Apply();

        mSliderStyle.normal.background = mSliderBack;

It’s working but how efficient is it and it’s clearly data duplication. I could probably release mAtlas after getting all my “subTexture” from the atlas but I wonder how unity handles the Texture2D. Does it pad the data to keep texture in power of 2 ? Is it the best way to do so ?

Plus doing so give me a lot of Texture2D object where I wanted only to handle 1 and use coordinates.

So is there an alternative or am I doing like its supposed to be ?

I also notices the PackTextures function but no function to actually use the packed texture or something. Unity is the third engine I use to build a professionnal game but the first one to not expose texture UV for 2D stuff. Needless to say the method I used in the code snippet above is not very intuitive to build interfaces.

Am I missing something ?

Thanks in advance !

2

There’s no direct way to use texture atlasing with Unity, but you can get around it by drawing the texture inside a group. Set the size of the group to the desired size of the onscreen image and then use negative XY placement of the texture in the group to position the visible part.

If you are using Photoshop, then another option is to use the slicing tool to isolate GUI elements from the image and then use Save For Web to export the separate images. This should work well unless you have reason to believe multiple images are a severe performance hit.