一、变换矩阵
UNITY_MATRIX_MVP 从object space转到 projection space（投影）
UNITY_MATRIX_MV 从object space转到camera space
UNITY_MATRIX_V 从world space转到camera space
UNITY_MATRIX_P 从camera space转到projection space
UNITY_MATRIX_VP 从world space转到projection space
UNITY_MATRIX_T_MV UNITY_MATRIX_MV 的转置矩阵
UNITY_MATRIX_IT_MV UNITY_MATRIX_MV的逆转置矩阵，法线的矩阵转换需要用变换矩阵的逆转置矩阵.
_Object2World 从object space转到world space
_World2Object _Object2World的逆矩阵，从world space 到object space
二、Camera and screen
|
Name |
Type |
Value |
|
_WorldSpaceCameraPos |
float3 |
World space position of the camera. 相机的世界坐标 |
|
_ProjectionParams |
float4 |
Xis 1.0 (or –1.0 if currently rendering with aflipped projection matrix),yis the camera’s near plane,zis the camera’s far plane andwis 1/FarPlane.
x 值是1.0或-1.0（当为反转的投影矩阵时） y 近截面，z远截面，w 1/远截面 |
|
_ScreenParams |
float4 |
xis the camera’s render target width in pixels,yis the camera’s render target height in pixels,zis 1.0 + 1.0/width andwis 1.0 + 1.0/height.
屏幕尺寸x宽，y高，z 1+1.0/width,w 1+1.0/height |
|
_ZBufferParams |
float4 |
Used to linearize Z buffer values. xis (1-far/near),yis (far/near),zis (x/far) andwis (y/far).
用于线性化zbuffer |
|
unity_OrthoParams |
float4 |
xis orthographic camera’s width,yis orthographic camera’s height,zis unused andwis 1.0 when camera is orthographic, 0.0 when perspective.
正交摄像机的相关参数,w值1时是正交投影，0时是透视投影 |
|
unity_CameraProjection |
float4x4 |
Camera’s projection matrix. 摄像机的投影矩阵 |
|
unity_CameraInvProjection |
float4x4 |
Inverse of camera’s projection matrix. 摄像机的投影矩阵的逆矩阵 |
|
unity_CameraWorldClipPlanes[6] |
float4 |
Camera frustum plane world space equations, in this order: left, right, bottom, top, near, far. 视锥体的左右下上远近 |
三、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). 帧间隔时间 |
四、forward渲染的光照变量
|
Name |
Type |
Value |
|
_LightColor0(declared in Lighting.cginc) |
fixed4 |
Light color. 光线颜色 |
|
_WorldSpaceLightPos0 |
float4 |
Directional lights: (world space direction, 0). Other lights: (world space position, 1). World space 光照位置,平行光的w值为0，其他光源的w值为1 |
|
_LightMatrix0(declared in AutoLight.cginc) |
float4x4 |
World-to-light matrix. Used to sample cookie & attenuation textures. World space转到light space矩阵 |
|
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. |
五、延迟光照相关变量
|
Name |
Type |
Value |
|
_LightColor |
float4 |
Light color.光照颜色 |
|
_LightMatrix0 |
float4x4 |
World-to-light matrix. Used to sample cookie & attenuation textures. World space转到light space矩阵 |
六、顶点光照相关变量
|
Name |
Type |
Value |
|
unity_LightColor |
half4[8] |
Light colors. 光照颜色 |
|
unity_LightPosition |
float4[8] |
View-space light positions. (-direction,0) for directional lights; (position,1) for point/spot lights. View space光照位置，平行光的w值为0，其他光源的w值为1 |
|
unity_LightAtten |
half4[8] |
Light attenuation factors.xis cos(spotAngle/2) or –1 for non-spot lights;yis 1/cos(spotAngle/4) or 1 for non-spot lights;zis quadratic attenuation;wis squared light range. 光照衰减值 |
|
unity_SpotDirection |
float4[8] |
View-space spot light positions; (0,0,1,0) for non-spot lights. View space聚光灯位置 |