for loop in shader

[anon78069058]

How do i use for loops in Unity shaders? I created a shader in RenderMonkey SM3 and now trying to port it to unity but i always get:

Program 'frag_surf', profile does not support "for" statements and "for" could not be unrolled

can some body help?

[Owen-Reynolds]

Hardware shaders (running on the graphics card) don't have loops in them at all, but they can fake them, which is called "unrolling." For example, if you write:

float4 col = 0;
// combine 4 copies of the texture, shifted slightly over:
for(int i=0; i<4; i++)
  col += tex2D( sampler1, UV + float2(0, i*0.05));
col = col/4; // average all thee

The compiler (or a helpful human -- you) unrolls it into:

float4 col = 0;
// combine 3 copies of the texture, shifted slighty over:
col += tex2D( sampler1, UV);
col += tex2D( sampler1, UV + float2(0, 0.05));
col += tex2D( sampler1, UV + float2(0, 0.10));
col += tex2D( sampler1, UV + float2(0, 0.15));
col = col/3; // average all thee

A software shader (running on the CPU, simulating the graphics card,) runs slower but can do anything, including loops. I assume they are useful for ultra-processed renders.

[thegreatzebadiah]

add:

#pragma target 4.0

to the top of the Pass and it should work…assuming your hardware supports shader model 4.0