Parameter Evaluation API

Parameter value querying from shaders. More...

Parameter Evaluation Macros
These macros evaluate a shader parameter of a specific type. There is a different macro for each supported parameter data type. This is the version that users will want to invoke most often since it passes the current shader globals and node by default. For example: enum LambertParams { p_Kd, p_Kd_color }; node_parameters { AiParameterFlt("Kd", 0.7f); AiParameterRgb("Kd_color", 1, 1, 1); // note that parameter ordering must match the enum above } shader_evaluate { float kd = AiShaderEvalParamFlt(p_Kd); ... } Please refer to ai_shader_parameval.h for a description of the functions called by these macros. Parameters pid Index in the shader's parameter enum list Returns Parameter value of the corresponding type. If the requested type doesn't match the parameter's true type, but the types are "link compatible", this query will silently perform the appropiate conversion; otherwise if the types are not compatible a value of zero (or the closest thing to 0 for the requested type, such as NULL or black) will be returned.
AI_API uint8_t	AiShaderEvalParamFuncByte (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API int	AiShaderEvalParamFuncInt (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API unsigned int	AiShaderEvalParamFuncUInt (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API bool	AiShaderEvalParamFuncBool (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API float	AiShaderEvalParamFuncFlt (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtRGB	AiShaderEvalParamFuncRGB (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtRGBA	AiShaderEvalParamFuncRGBA (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtVector	AiShaderEvalParamFuncVec (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtVector2	AiShaderEvalParamFuncVec2 (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtString	AiShaderEvalParamFuncStr (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API void *	AiShaderEvalParamFuncPtr (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtArray *	AiShaderEvalParamFuncArray (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtMatrix *	AiShaderEvalParamFuncMtx (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API int	AiShaderEvalParamFuncEnum (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtClosureList	AiShaderEvalParamFuncClosure (AtShaderGlobals *sg, const AtNode *node, int pid)
AI_API AtRGB	AiShaderEvalParamFuncOpacity (AtShaderGlobals *sg, const AtNode *node, int pid)
#define	AiShaderEvalParamByte(pid)   AiShaderEvalParamFuncByte (sg,node,pid)
#define	AiShaderEvalParamInt(pid)   AiShaderEvalParamFuncInt (sg,node,pid)
#define	AiShaderEvalParamUInt(pid)   AiShaderEvalParamFuncUInt (sg,node,pid)
#define	AiShaderEvalParamBool(pid)   AiShaderEvalParamFuncBool (sg,node,pid)
#define	AiShaderEvalParamFlt(pid)   AiShaderEvalParamFuncFlt (sg,node,pid)
#define	AiShaderEvalParamRGB(pid)   AiShaderEvalParamFuncRGB (sg,node,pid)
#define	AiShaderEvalParamRGBA(pid)   AiShaderEvalParamFuncRGBA (sg,node,pid)
#define	AiShaderEvalParamVec(pid)   AiShaderEvalParamFuncVec (sg,node,pid)
#define	AiShaderEvalParamVec2(pid)   AiShaderEvalParamFuncVec2 (sg,node,pid)
#define	AiShaderEvalParamStr(pid)   AiShaderEvalParamFuncStr (sg,node,pid)
#define	AiShaderEvalParamPtr(pid)   AiShaderEvalParamFuncPtr (sg,node,pid)
#define	AiShaderEvalParamArray(pid)   AiShaderEvalParamFuncArray (sg,node,pid)
#define	AiShaderEvalParamMtx(pid)   AiShaderEvalParamFuncMtx (sg,node,pid)
#define	AiShaderEvalParamEnum(pid)   AiShaderEvalParamFuncEnum (sg,node,pid)
#define	AiShaderEvalParamClosure(pid)   AiShaderEvalParamFuncClosure(sg,node,pid)
#define	AiShaderEvalParamOpacity(pid)   AiShaderEvalParamFuncOpacity(sg,node,pid)

Detailed Description

Parameter value querying from shaders.

If the parameter is linked to another shader, the child shader will be executed and its output will be returned.

This is the recommended mechanism for parameter evaluation inside a shader. Note that, for parameters that are not linked, the AiNodeGet* API (AiNodeGetInt(), etc) also returns the static value of the parameter. For both consistency and optimal performance, it is recommended to always use the AiShaderEvalParam* API described in this module.