How do I generate mipmaps at runtime?

Question

How do I generate mipmaps at runtime for a texture which is loaded using the WWW class? I can load this texture at runtime and apply it to a material, but mipmaps aren't automatically generated. Does Unity have a runtime function to do this, or will I have to create my own script to generate mipmaps using SetPixels?

Answer 1

Best Answer

Answer by duck · Jan 17, 2010 at 09:40 PM

Having skimmed the docs, I can't see a built in method to do this. Perhaps you could make use of the fact that "Apply()" auto-generates mipmaps by default.

Try myTexture.Apply(); on its own after getting the texture first. If that doesn't work you could venture into 'ugly hack' territory by trying this to force a draw using SetPixels which would then hopefully make 'apply' do its thing (just a guess, untested & may not work!):

myTexture.SetPixels( myTexture.GetPixels(0,0,myTexture.width,myTexture.height) );
myTexture.Apply();

If that doesn't work, it may be that there's something different about WWW.texture, and perhaps you have to use WWW.LoadImageIntoTexture to load the image into an existing Texture2D rather than just using WWW.texture directly (and perhaps even try the above things on the texture afterwards).

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capnbishop · Jan 17, 2010 at 11:58 PM 1

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Using Texture2D.SetPixels(Texture2D.GetPixels()) works great. Thank you.

capnbishop · Jan 18, 2010 at 12:01 AM 1

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Specifically, this must be done on a fresh texture, so the actual code will end up looking a little more like this:

var tex1 = www.texture; var tex2 = new Texture2D(tex1.width, tex1.height); tex2.SetPixels(tex1.GetPixels()); tex2.Apply(true);

bcsanches · May 06, 2011 at 01:37 AM 0

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Also here it only works when creating a new texture.

pld · Aug 27, 2016 at 01:39 AM 0

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Eric5h5's answer is now the best answer.

Answer 2

Answer by Eric5h5 · Jan 17, 2010 at 09:42 PM

Create a texture first that has mipmaps, then use WWW.LoadImageIntoTexture.

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pld · Aug 27, 2016 at 01:52 AM 0

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Note that the texture you create must have mipmapCount >= 2. So if you create a 1x1 dummy texture with mips and pass it to WWW.LoadImageIntoTexture, you will be sad.

Answer 3

Answer by gwfuserPS · Sep 14, 2015 at 11:41 PM

Set the 4th parameter to true it will enable the mipmap.

Texture2D(int width, int height, TextureFormat format, bool mipmap, bool linear)

http://docs.unity3d.com/ScriptReference/Texture2D-ctor.html

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How do I generate mipmaps at runtime?

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