Hello, Aras.I'm a Chinese Developer.Maybe my English is poor,Please forgive me. -qusetion : In the Unity Shader Official Document. target 2.0 support 8 interpolators. What's the mean of interpolators. How do i understand it??

"interpolators" is a DirectX term, for example in OpenGL they are called "varyings" sometimes. It's basically the "things" you pass from the vertex shader into the pixel/fragment shader. In shaders these typically have "TEXCOORDn" semantics on them.

Platforms like OpenGL ES 2.0 are often limited to 8 four-component vectors (so in total up to 32 numbers) that can be written to from the vertex shader and read by the fragment shader. DirectX9 shader model 2 (SM2.0) is slightly more complicated, as it allows up to 8 TEXCOORDn interpolators (each being float, float2, float3 or float4), and additionally two low-precision COLORn interpolators (again each being float..float4).

Later shader models/APIs do away with that split between "texcoord vs color" interpolators, and e.g. DirectX9 shader model 3 says "up to 10 float..float4 interpolators". OpenGL ES 3.0 and DirectX10 says "up to 16" etc.

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About Aras Pranckevičius:

Graphics programmer and code plumber at Unity

Kaunas, Lithuania

http://aras-p.info/

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