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Unity Engine

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Script Reference

Unity Engine

Shader methods in the Built-In Render Pipeline reference

Use built-in functions to transform positions and other values.
読み終わるまでの所要時間 5 分最終更新 11日前
重要
The Built-In Render Pipeline is deprecated and will be made obsolete in a future release.
It remains supported, including bug fixes and maintenance, through the full Unity 6.7 LTS lifecycle.
For more information on migration, refer to Migrating from the Built-In Render Pipeline to the Universal Render Pipeline and Render pipeline feature comparison.
Unity has a number of built-in utility functions in UnityCG.cginc designed to make writing shaders simpler and easier.

Transform positions

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.

Transform other values

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.
half Luminance (half3 c)
Converts color to luminance (grayscale).
half3 DecodeLightmap (half4 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

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

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

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.

Texture and sampler macros

Macro:

Use:

UNITY_DECLARE_TEX2D(name)
Declares a Texture and Sampler pair.
UNITY_DECLARE_TEX2D_NOSAMPLER(name)
Declares a Texture without a Sampler.
UNITY_DECLARE_TEX2DARRAY(name)
Declares a Texture array Sampler variable.
UNITY_SAMPLE_TEX2D(name,uv)
Sample from a Texture and Sampler pair, using given Texture coordinate.
UNITY_SAMPLE_TEX2D_SAMPLER( name,samplername,uv)
Sample from Texture (name), using a Sampler from another Texture (samplername).
UNITY_SAMPLE_TEX2DARRAY(name,uv)
Sample from a Texture array with a float3 UV; the z component of the coordinate is array element index.
UNITY_SAMPLE_TEX2DARRAY_LOD(name,uv,lod)
Sample from a Texture array with an explicit mipmap level.

Shadow mapping macros

Declaring and sampling shadow maps can be very different depending on the platform. Unity has several macros to help with this:

Macro:

Use:

UNITY_DECLARE_SHADOWMAP(tex)
Declares a shadowmap Texture variable with name "tex".
UNITY_SAMPLE_SHADOW(tex,uv)
Samples shadowmap Texture "tex" at given "uv" coordinate (XY components are Texture location, Z component is depth to compare with). Returns single float value with the shadow term in 0..1 range.
UNITY_SAMPLE_SHADOW_PROJ(tex,uv)
Similar to above, but does a projective shadowmap read. "uv" is a float4, all other components are divided by .w for doing the lookup.
The format of 
tex
must be RenderTextureFormat.Shadowmap.
注
Not all graphics cards support shadowmaps. Use SystemInfo.SupportsRenderTextureFormat to check for support.

Depth Texture helper macros

Most of the time, Depth Texture are used to render Depth from the Camera. The UnityCG.cginc include file contains some macros to deal with the above complexity in this case:
  • COMPUTE_EYEDEPTH(i): computes eye space depth of the vertex and outputs it in o. Use it in a vertex program when not rendering into a depth texture.
  • DECODE_EYEDEPTH(i)/LinearEyeDepth(i): given high precision value from depth texture i, returns corresponding eye space depth.
  • Linear01Depth(i): given high precision value from depth texture i, returns corresponding linear depth in range between 0 and 1.
  • UNITY_TRANSFER_DEPTH(o): Deprecated. Computes the eye space depth of the vertex and outputs it in o (which must be a float2). On platforms with native depth textures this macro does nothing, because the Z buffer value is rendered implicitly.
  • UNITY_OUTPUT_DEPTH(i): Deprecated. Returns eye space depth from i (which must be a float2). On platforms with native depth textures this macro always returns zero, because the Z buffer value is rendered implicitly.
注
On DX11/12 and Metal, the Z buffer range is 1-0 and UNITY_REVERSED_Z is defined. On other platforms, the range is 0-1.
For example, this shader would render depth of its GameObjects:
Shader "Render Depth" {	SubShader {	    Tags { "RenderType"="Opaque" }	    Pass {			HLSLPROGRAM			#pragma vertex vert			#pragma fragment frag			#include "UnityCG.cginc"			struct v2f {			    float4 pos : SV_POSITION;			    float2 depth : TEXCOORD0;			};			v2f vert (appdata_base v) {			    v2f o;			    o.pos = UnityObjectToClipPos(v.vertex);			    UNITY_TRANSFER_DEPTH(o.depth);			    return o;			}			half4 frag(v2f i) : SV_Target {			    UNITY_OUTPUT_DEPTH(i.depth);			}			ENDHLSL	    }	}}