引擎内置的ShaderAPI参考

类型

虽然可以直接使用GLSL类型(vec4或mat4)，但我们建议使用以下类型别名:

Name	GLSL type	Description
bool2	bvec2	A vector of 2 booleans
bool3	bvec3	A vector of 3 booleans
bool4	bvec4	A vector of 4 booleans
int2	ivec2	A vector of 2 integers
int3	ivec3	A vector of 3 integers
int4	ivec4	A vector of 4 integers
uint2	uvec2	A vector of 2 unsigned integers
uint3	uvec3	A vector of 3 unsigned integers
uint4	uvec4	A vector of 4 unsigned integers
float2	float2	A vector of 2 floats
float3	float3	A vector of 3 floats
float4	float4	A vector of 4 floats
float4x4	mat4	A 4x4 float matrix
float3x3	mat3	A 3x3 float matrix

数学相关

Name	Type	Description
PI	float	A constant that represent $\pi$
HALF_PI	float	A constant that represent $\frac{\pi}{2}$
saturate(float x)	float	Clamps the specified value between 0.0 and 1.0
pow5(float x)	float	Computes $x^5$
sq(float x)	float	Computes $x^2$
max3(float3 v)	float	Returns the maximum value of the specified float3
mulMat4x4Float3(float4x4 m, float3 v)	float4	Returns $m * v$
mulMat3x3Float3(float4x4 m, float3 v)	float4	Returns $m * v$

矩阵相关

Name	Type	Description
getViewFromWorldMatrix()	float4x4	Matrix that converts from world space to view/eye space
getWorldFromViewMatrix()	float4x4	Matrix that converts from view/eye space to world space
getClipFromViewMatrix()	float4x4	Matrix that converts from view/eye space to clip (NDC) space
getViewFromClipMatrix()	float4x4	Matrix that converts from clip (NDC) space to view/eye space
getClipFromWorldMatrix()	float4x4	Matrix that converts from world to clip (NDC) space
getWorldFromClipMatrix()	float4x4	Matrix that converts from clip

帧数据常量

Name	Type	Description
getResolution()	float4	Dimensions of the view's effective (physical) viewport in pixels: width, height, 1 / width, 1 / height. This might be different from View::getViewport() for instance because of added rendering guard-bands.
getWorldCameraPosition()	float3	Position of the camera/eye in world space (see note below)
getWorldOffset()	float3	[deprecated] The shift required to obtain API-level world space. Use getUserWorldPosition() instead
getUserWorldFromWorldMatrix()	float4x4	Matrix that converts from world space to API-level (user) world space.
getTime()	float	Current time as a remainder of 1 second. Yields a value between 0 and 1
getUserTime()	float4	Current time in seconds: time, (double)time - time, 0, 0
getUserTimeMod(float m)	float	Current time modulo m in seconds
getExposure()	float	Photometric exposure of the camera
getEV100()	float	Exposure value at ISO 100 of the camera

仅顶点着色器可访问

Name	Type	Description
getPosition()	float4	Vertex position in the domain defined by the material (default: object/model space)
getCustom0() to getCustom7()	float4	Custom vertex attribute
getWorldFromModelMatrix()	float4x4	Matrix that converts from model (object) space to world space
getWorldFromModelNormalMatrix()	float3x3	Matrix that converts normals from model (object) space to world space
getVertexIndex()	int	Index of the current vertex

仅像素着色器可访问

Name	Type	Description
getWorldTangentFrame()	float3x3	Matrix containing in each column the tangent (frame[0]), bi-tangent (frame[1]) and normal (frame[2]) of the vertex in world space. If the material does not compute a tangent space normal for bump mapping or if the shading is not anisotropic, only the normal is valid in this matrix.
getWorldPosition()	float3	Position of the fragment in world space (see note below about world-space)
getUserWorldPosition()	float3	Position of the fragment in API-level (user) world-space (see note below about world-space)
getWorldViewVector()	float3	Normalized vector in world space from the fragment position to the eye
getWorldNormalVector()	float3	Normalized normal in world space, after bump mapping (must be used after prepareMaterial())
getWorldGeometricNormalVector()	float3	Normalized normal in world space, before bump mapping (can be used before prepareMaterial())
getWorldReflectedVector()	float3	Reflection of the view vector about the normal (must be used after prepareMaterial())
getNormalizedViewportCoord()	float3	Normalized user viewport position (i.e. NDC coordinates normalized to [0, 1] for the position, [1, 0] for the depth), can be used before prepareMaterial()). Because the user viewport is smaller than the actual physical viewport, these coordinates can be negative or superior to 1 in the non-visible area of the physical viewport.
getNdotV()	float	The result of dot(normal, view), always strictly greater than 0 (must be used after prepareMaterial())
getColor()	float4	Interpolated color of the fragment, if the color attribute is required
getUV0()	float2	First interpolated set of UV coordinates, only available if the uv0 attribute is required
getUV1()	float2	First interpolated set of UV coordinates, only available if the uv1 attribute is required
getMaskThreshold()	float	Returns the mask threshold, only available when blending is set to masked
inverseTonemap(float3)	float3	Applies the inverse tone mapping operator to the specified linear sRGB color and returns a linear sRGB color. This operation may be an approximation and works best with the "Filmic" tone mapping operator
inverseTonemapSRGB(float3)	float3	Applies the inverse tone mapping operator to the specified non-linear sRGB color and returns a linear sRGB color. This operation may be an approximation and works best with the "Filmic" tone mapping operator
luminance(float3)	float	Computes the luminance of the specified linear sRGB color
ycbcrToRgb(float, float2)	float3	Converts a luminance and CbCr pair to a sRGB color
uvToRenderTargetUV(float2)	float2	Transforms a UV coordinate to allow sampling from a RenderTarget attachment