1. @agatestudio
Shaders in Unity
Zoel
Knight
Agate Studio

4. Geometry Deformation.
Pixels processing.
Math intensive calculations.
GPGPU.

5. • D3D / OpenGL Render Pipeline Stages
Vertex Shader
Fragment Shader
Geometry ShaderTessellation
Primitive
Assembly
Rasterization
Raster
Operations
Pixels
Vertex
Assembly
Screen
Hull DomainTessellator Stage

7. • Runs per input vertex.
• Transform 3D into 2D (screen space) position.
• Can perform vertex position, color ,UV
(texture coordinates) manipulation.
• Cannot create new vertices.
• Cannot “see” other vertices.

9. • Runs per fragment.
• Computes fragment’s color.
• With fragment shader you can create: bump
mapping, shadows, lights, post processing
effects and other cool shit.
• See http://glsl.heroku.com/

11. Shaders before Cg/HLSL/GLSL:
TEX H0, f[TEX0], TEX4, 2D;
TEX H1, f[TEX2], TEX5, CUBE;
DP3X H1.xyz, H1, LUMINANCE;
MULX H0.w, H0.w, LUMINANCE.w;
MULX H1.w, H1.x, H1.x;
MOVH H2, f[TEX3].wxyz;
MULX H1.w, H1.x, H1.w;
DP3X H0.xyz, H2.xzyw, H0;
MULX H0.xyz, H0, H1.w;
TEX H1, f[TEX0], TEX1, 2D;
TEX H3, f[TEX0], TEX3, 2D;
MULX H0.xyz, H0, H3;
Bla… Bla… Bla…

12. CG Shader
• “C for graphics”
• High Level language.
Cg != C
• No classes, pointers, malloc , IO etc.
• Cg has loops, conditionals, functions/overloads.
• Member variables, local (temporary) variables constants.
• Data types: numeric primitives, vectors, matrices, arrays, structs,
and interfaces.
• Built-in trig and other math methods.
• Static & Dynamic compilation.

13. Cg and Graphics APIs interop scheme:

15. 3 Ways of writing shaders in Unity:
Surface shaders.
Vertex and fragment shaders.
Fixed function shaders.

16. Simple Custom shader:

17. Passing vertex attributes and uniforms
• Programmable setup (via scripts):
- SetFloat()
- SetVector()
- SetMatrix()
- SetColor()
- SetBuffer()
- SetTexture()
• Shader lab properties:
[UniformName+(*“Uniform property panel name“+, *Data Type+) =
[Default value]

18. Accessing uniforms:
Very simple!!!
Declare uniforms in the shader header with exactly the same names and data
types as they have in Shader Lab prop block.

19. Thank you!!!
http://aras-p.info/blog/
http://docs.unity3d.com/Documentation/Manual/Shaders.html
http://http.developer.nvidia.com/CgTutorial/cg_tutorial_chapter01.html
https://developer.nvidia.com/shader-library
http://wiki.unity3d.com/index.php/Shaders
zoelbastianbach@agategames.com