Unity 内建数据索引

看到多少补多少

顶点输入类型

UnityCG.cginc Line:58 

struct appdata_base {
    float4 vertex : POSITION;
    float3 normal : NORMAL;
    float4 texcoord : TEXCOORD0;
    UNITY_VERTEX_INPUT_INSTANCE_ID
};

struct appdata_tan {
    float4 vertex : POSITION;
    float4 tangent : TANGENT;
    float3 normal : NORMAL;
    float4 texcoord : TEXCOORD0;
    UNITY_VERTEX_INPUT_INSTANCE_ID
};

struct appdata_full {
    float4 vertex : POSITION;
    float4 tangent : TANGENT;
    float3 normal : NORMAL;
    float4 texcoord : TEXCOORD0;
    float4 texcoord1 : TEXCOORD1;
    float4 texcoord2 : TEXCOORD2;
    float4 texcoord3 : TEXCOORD3;
    fixed4 color : COLOR;
    UNITY_VERTEX_INPUT_INSTANCE_ID
};

内建一些变量

Transformations

All these matrices are float4x4 type.

Name	Value
UNITY_MATRIX_MVP	Current model * view * projection matrix.
UNITY_MATRIX_MV	Current model * view matrix.
UNITY_MATRIX_V	Current view matrix.
UNITY_MATRIX_P	Current projection matrix.
UNITY_MATRIX_VP	Current view * projection matrix.
UNITY_MATRIX_T_MV	Transpose of model * view matrix.
UNITY_MATRIX_IT_MV	Inverse transpose of model * view matrix.
unity_ObjectToWorld	Current model matrix.
unity_WorldToObject	Inverse of current world matrix.

Camera and screen

These variables will correspond to the Camera that is rendering. For example during shadowmap rendering, they will still refer to the Camera component values, and not the “virtual camera” that is used for the shadowmap projection.

Name	Type	Value
_WorldSpaceCameraPos	float3	World space position of the camera.
_ProjectionParams	float4	x is 1.0 (or –1.0 if currently rendering with a flipped projection matrix), y is the camera’s near plane, z is the camera’s far plane and w is 1/FarPlane.
_ScreenParams	float4	x is the width of the camera’s target texture in pixels, y is the height of the camera’s target texture in pixels, z is 1.0 + 1.0/width and w is 1.0 + 1.0/height.
_ZBufferParams	float4	Used to linearize Z buffer values. x is (1-far/near), y is (far/near), z is (x/far) and w is (y/far).
unity_OrthoParams	float4	x is orthographic camera’s width, y is orthographic camera’s height, z is unused and w is 1.0 when camera is orthographic, 0.0 when perspective.
unity_CameraProjection	float4x4	Camera’s projection matrix.
unity_CameraInvProjection	float4x4	Inverse of camera’s projection matrix.
unity_CameraWorldClipPlanes[6]	float4	Camera frustum plane world space equations, in this order: left, right, bottom, top, near, far.

Time

Name	Type	Value
_Time	float4	Time since level load (t/20, t, t*2, t*3), use to animate things inside the shaders.
_SinTime	float4	Sine of time: (t/8, t/4, t/2, t).
_CosTime	float4	Cosine of time: (t/8, t/4, t/2, t).
unity_DeltaTime	float4	Delta time: (dt, 1/dt, smoothDt, 1/smoothDt).

Lighting

灯光部分 根据LightMode 不同可用的内建数据也是不同的

Light parameters are passed to shaders in different ways depending on which Rendering Path is used, and which LightMode Pass Tag is used in the shader.

Forward rendering (ForwardBase and ForwardAdd pass types):

Name	Type	Value
_LightColor0 (declared in Lighting.cginc)	fixed4	Light color.
_WorldSpaceLightPos0	float4	Directional lights: (world space direction, 0). Other lights: (world space position, 1).
_LightMatrix0 (declared in AutoLight.cginc)	float4x4	World-to-light matrix. Used to sample cookie & attenuation textures.
unity_4LightPosX0, unity_4LightPosY0, unity_4LightPosZ0	float4	(ForwardBase pass only) world space positions of first four non-important point lights.
unity_4LightAtten0	float4	(ForwardBase pass only) attenuation factors of first four non-important point lights.
unity_LightColor	half4[4]	(ForwardBase pass only) colors of of first four non-important point lights.
unity_WorldToShadow	float4x4[4]	World-to-shadow matrices. One matrix for spot lights, up to four for directional light cascades.

Deferred shading and deferred lighting, used in the lighting pass shader (all declared in UnityDeferredLibrary.cginc):

Name	Type	Value
_LightColor	float4	Light color.
_LightMatrix0	float4x4	World-to-light matrix. Used to sample cookie & attenuation textures.
unity_WorldToShadow	float4x4[4]	World-to-shadow matrices. One matrix for spot lights, up to four for directional light cascades.

Spherical harmonics coefficients (used by ambient and light probes) are set up for ForwardBase, PrePassFinal and Deferred pass types. They contain 3rd order SH to be evaluated by world space normal (see ShadeSH9 from UnityCG.cginc). The variables are all half4 type, unity_SHAr and similar names.

Vertex-lit rendering (Vertex pass type):

Up to 8 lights are set up for a Vertex pass type; always sorted starting from the brightest one. So if you want to render objects affected by two lights at once, you can just take first two entries in the arrays. If there are less lights affecting the object than 8, the rest will have their color set to black.

Name	Type	Value
unity_LightColor	half4[8]	Light colors.
unity_LightPosition	float4[8]	View-space light positions. (-direction,0) for directional lights; (position,1) for point/spot lights.
unity_LightAtten	half4[8]	Light attenuation factors. x is cos(spotAngle/2) or –1 for non-spot lights; y is 1/cos(spotAngle/4) or 1 for non-spot lights; z is quadratic attenuation; w is squared light range.
unity_SpotDirection	float4[8]	View-space spot light positions; (0,0,1,0) for non-spot lights.

Fog and Ambient

Name	Type	Value
unity_AmbientSky	fixed4	Sky ambient lighting color in gradient ambient lighting case.
unity_AmbientEquator	fixed4	Equator ambient lighting color in gradient ambient lighting case.
unity_AmbientGround	fixed4	Ground ambient lighting color in gradient ambient lighting case.
UNITY_LIGHTMODEL_AMBIENT	fixed4	Ambient lighting color (sky color in gradient ambient case). Legacy variable.
unity_FogColor	fixed4	Fog color.
unity_FogParams	float4	Parameters for fog calculation: (density / sqrt(ln(2)), density / ln(2), –1/(end-start), end/(end-start)). x is useful for Exp2 fog mode, y for Exp mode, z and w for Linear mode.

Various

Name	Type	Value
unity_LODFade	float4	Level-of-detail fade when using LODGroup. x is fade (0..1), y is fade quantized to 16 levels, z and w unused.

 内建函数

Vertex transformation functions in UnityCG.cginc

Function:	Description:
float4 UnityObjectToClipPos(float3 pos)	Transforms a point from object space to the camera’s clip space in homogeneous coordinates. This is the equivalent of mul(UNITY_MATRIX_MVP, float4(pos, 1.0)), and should be used in its place.
float3 UnityObjectToViewPos(float3 pos)	Transforms a point from object space to view space. This is the equivalent of mul(UNITY_MATRIX_MV, float4(pos, 1.0)).xyz, and should be used in its place.

Generic helper functions in UnityCG.cginc

Function:	Description:
float3 WorldSpaceViewDir (float4 v)	Returns world space direction (not normalized) from given object space vertex position towards the camera.
float3 ObjSpaceViewDir (float4 v)	Returns object space direction (not normalized) from given object space vertex position towards the camera.
float2 ParallaxOffset (half h, half height, half3 viewDir)	calculates UV offset for parallax normal mapping.
fixed Luminance (fixed3 c)	Converts color to luminance (grayscale).
fixed3 DecodeLightmap (fixed4 color)	Decodes color from Unity lightmap (RGBM or dLDR depending on platform).
float4 EncodeFloatRGBA (float v)	Encodes [0..1) range float into RGBA color, for storage in low precision render target.
float DecodeFloatRGBA (float4 enc)	Decodes RGBA color into a float.
float2 EncodeFloatRG (float v)	Encodes [0..1) range float into a float2.
float DecodeFloatRG (float2 enc)	Decodes a previously-encoded RG float.
float2 EncodeViewNormalStereo (float3 n)	Encodes view space normal into two numbers in 0..1 range.
float3 DecodeViewNormalStereo (float4 enc4)	Decodes view space normal from enc4.xy.

Forward rendering helper functions in UnityCG.cginc

These functions are only useful when using forward rendering (ForwardBase or ForwardAdd pass types).

Function:	Description:
float3 WorldSpaceLightDir (float4 v)	Computes world space direction (not normalized) to light, given object space vertex position.
float3 ObjSpaceLightDir (float4 v)	Computes object space direction (not normalized) to light, given object space vertex position.
float3 Shade4PointLights (...)	Computes illumination from four point lights, with light data tightly packed into vectors. Forward rendering uses this to compute per-vertex lighting.

Screen-space helper functions in UnityCG.cginc

The following functions are helpers to compute coordinates used for sampling screen-space textures. They return float4 where the final coordinate to sample texture with can be computed via perspective division (for example xy/w).

The functions also take care of platform differences in render texture coordinates.

Function:	Description:
float4 ComputeScreenPos (float4 clipPos)	Computes texture coordinate for doing a screenspace-mapped texture sample. Input is clip space position.
float4 ComputeGrabScreenPos (float4 clipPos)	Computes texture coordinate for sampling a GrabPass texure. Input is clip space position.

Vertex-lit helper functions in UnityCG.cginc

These functions are only useful when using per-vertex lit shaders (“Vertex” pass type).

Function:	Description:
float3 ShadeVertexLights (float4 vertex, float3 normal)	Computes illumination from four per-vertex lights and ambient, given object space position & normal.