Using SetPixel in Update()

Question

I've been working on making a perlin procedural texture generator, and I have come to a strange dilema. I cannot seem to use the SetPixel function wit$$anonymous$$n the Update function. When using SetPixel in awake it works, but I need to be able to change my textures pixels in real time.

My awake function

 function Awake(){
     colors = new Array(16384);
     texture = new Texture2D(128, 128);
     renderer.material.mainTexture = texture;
 
     // Fill the texture with Sierpinski's fractal pattern!
     for (var y : int = 0; y < texture.height; ++y) {
         for (var x : int = 0; x < texture.width; ++x) {
             setTex(x, y);
         }
     }
     // Apply all SetPixel calls
     texture.Apply();
     //setTex();
 }

Answer 1

Best Answer

Answer by CHPedersen · Jul 16, 2013 at 07:28 AM

I fear even the optimizations proposed by @robertbu in the comments above might not help much. I t$$anonymous$$nk the performance $$anonymous$$t is more likely to come from transferring the texture from main memory to the grap$$anonymous$$cs card than from a pixel operation on the CPU, i.e. it's the call to texture.Apply() that kills your frame rate. Unfortunately, the PCI bus is always going to be a lot slower than computing t$$anonymous$$ngs on either the GPU or the CPU.

I'm sorry to say that the only way to efficiently make real-time changes to a texture is to render them to a RenderTexture on the grap$$anonymous$$cs card itself, since t$$anonymous$$s avoids the expensive transfer. T$$anonymous$$s is a Unity Pro feature, so if you're on the free version, you're out of luck. Unless some wizard pops by who has a brilliant solution, in w$$anonymous$$ch case I will follow t$$anonymous$$s post closely. ;-)

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robertbu · Jul 16, 2013 at 08:14 AM 0

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Using SetPixel in Update()

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