shader内置变量
内置变量都在UnityShaderVariables.cginc
文件中声明
变换矩阵
All these matrices arefloat4x4 type.
Name |
Value |
UNITY_MATRIX_MVP |
Current model * view * projection matrix. 从object space转到 projection space |
UNITY_MATRIX_MV |
Current model * view matrix. 从object space转到camera space |
UNITY_MATRIX_V |
Current view matrix. 从world space转到camera space |
UNITY_MATRIX_P |
Current projection matrix. 从camera space转到projection space |
UNITY_MATRIX_VP |
Current view * projection matrix. 从world space转到projection space |
UNITY_MATRIX_T_MV |
Transpose of model * view matrix. UNITY_MATRIX_MV 的转置矩阵 |
UNITY_MATRIX_IT_MV |
Inverse transpose of model * view matrix. 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 |
Current model matrix. 从object space转到world space |
_World2Object |
Inverse of current world matrix. _Object2World的逆矩阵,从world space 到object space |
Camera and screen
These variables will correspond to the Camerathat 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. 相机的世界坐标 |
_ProjectionParams |
float4 |
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 |
float4 |
屏幕尺寸x宽,y高,z 1+1.0/width,w 1+1.0/height |
|
float4 |
Used to linearize Z buffer values. 用于线性化zbuffer |
|
unity_OrthoParams |
float4 |
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 |
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 |
Lighting
Light parameters are passed to shaders in differentways depending on which Rendering Pathis used, and which LightModePass Tag is used in the shader.
Forward rendering (ForwardBase
andForwardAdd
passtypes):
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. |
在正向渲染中,影响物体的最亮的几个光源使用逐像素光照模式。接下来,最多有4个点光源会以逐顶点渲染的方式被计算。其他光源将以球面调和(Spherical Harmonics)的方式进行计算,球面调和技术计算很快但只能得到近似值。
Deferred shading and deferred lighting, usedin the lighting pass shader (all declared in UnityDeferredLibrary.cginc):
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 |
Spherical harmonics coefficients (used by ambientand light probes) are set up forForwardBase
,PrePassFinal
andDeferred
passtypes. They contain 3rd order SH to be evaluated by world space normal (seeShadeSH9
fromUnityCG.cginc).The variables are all half4 type,unity_SHAr
andsimilar names.
Vertex-lit rendering (Vertex
pass type):
Up to 8 lights are set up for aVertex
pass type; always sorted starting from the brightest one. So if you wantto render objects affected by two lights at once, you can just take first two entriesin the arrays. If there are less lights affecting the object than 8, the rest willhave their color set to black.
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 |
Fog and Ambient
Window > Lighting> Scene 里设置的相应的颜色
Name |
Type |
Value |
UNITY_LIGHTMODEL_AMBIENT |
fixed4 |
Ambient lighting color (Equator ambient in three-color lighting case). |
unity_AmbientSky |
fixed4 |
Sky ambient lighting color in three-color lighting case. |
unity_AmbientGround |
fixed4 |
Ground ambient lighting color in three-color lighting case. |
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. |
Built-in shader helper functions
其他一些杂七杂八的变量
#pragmatarget 3.0 定义Shader模型为Shader Model 3.0,
Image Effect取到depthTexture相关的步骤
GetComponent<Camera>().depthTextureMode=DepthTextureMode.Depth//设置摄像机模式
Shader中声明 sampler2D _CameraDepthTexture;//深度纹理的声明
取样float d = SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture,uv) , //0-1越远越大
生成一个深度+法线纹理
GetComponent<Camera>().depthTextureMode=DepthTextureMode.DepthNormals;
Shader中声明
sampler2D _CameraDepthTexture;//深度纹理的声明
sampler2D _CameraNormalsTexture;//法线纹理的声明
用tex2d方法进行法线取样
或者声明
sampler2D _CameraDepthNormalsTexture.//
用DecodeDepthNormal(tex2D(_CameraDepthNormalsTexture,i.screen.xy), depthValue, normalValues);取得法线跟深度值
DecodeDepthNormal
to decode depth and normalfrom the encoded pixel value. Returned depth is in 0.1 range.
_CameraDepthTexture
always refers to the camera’sprimary depth texture. By contrast, you can use_LastCameraDepthTexture
to refer to the last depthtexture rendered by any camera.This couldbe useful for example if you render a half-resolution depth texture in script usinga secondary camera and want to make it available to a post-process shader.
_LastCameraDepthTexture
取得最后渲染的深度纹理
Texturesize 纹理尺寸获得
{TextureName}_TexelSize
- a float4 property contains texture size information:
x
contains1.0/width
y
contains1.0/height
z
containswidth
w
containsheight
例子
uniform float4 _MainTex_TexelSize分别对应Vector4(1 / width, 1 / height, width, height),
Texturetiling & offset 纹理偏移
Materialsoften have Tiling and Offset fields for their texture properties.This information is passed into shaders in a float4 {TextureName}_ST
property:
x
containsX tiling value
y
containsY tiling value
z
containsX offset value
w
containsY offset value
例:
o.uv =TRANSFORM_TEX(v.texcoord,_MainTex);
相当于
o.uv = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;