Shader globals data structure. More...
#include <ai_shaderglobals.h>
Data Fields | |
| int32_t | x |
| X raster-space coordinate of this ray tree. | |
| int32_t | y |
| Y raster-space coordinate of this ray tree. | |
| float | px |
| subpixel X coordinate of this ray in [0,1) | |
| float | py |
| subpixel Y coordinate of this ray in [0,1) | |
| uint16_t | si |
| subpixel sample index | |
| uint16_t | transp_index |
| transparency index | |
| AtVector | Ro |
| ray origin (typically the camera position) | |
| AtVector | Rd |
| ray direction (normalized) | |
| float | Rl |
| ray length (|Ro-P|) | |
| uint16_t | tid |
| thread ID | |
| uint8_t | Rt |
| ray type | |
| uint8_t | bounces |
| recursion level for the ray that created this hit | |
| uint8_t | bounces_diffuse |
| ray diffuse depth level | |
| uint8_t | bounces_specular |
| ray specular depth level | |
| uint8_t | bounces_reflect |
| ray reflection depth level | |
| uint8_t | bounces_transmit |
| ray transmission depth level | |
| uint8_t | bounces_volume |
| ray volume depth level | |
| bool | fhemi |
| force hemispherical lighting (use only upper hemisphere) | |
| float | time |
| absolute time, between shutter-open and shutter-close | |
| AtNode * | Op |
| pointer to the object being shaded | |
| AtNode * | proc |
| pointer to the procedural object (if exists) | |
| AtNode * | shader |
| pointer to the current shader | |
| const AtShaderGlobals * | psg |
| parent shader globals (last shaded) | |
| AtVector | Po |
| shading point in object-space | |
| AtVector | P |
| shading point in world-space | |
| AtVector | dPdx |
| surface derivative wrt screen X-axis | |
| AtVector | dPdy |
| surface derivative wrt screen Y-axis | |
| AtVector | N |
| shading normal | |
| AtVector | Nf |
| face-forward shading normal | |
| AtVector | Ng |
| geometric normal | |
| AtVector | Ngf |
| face-forward geometric normal | |
| AtVector | Ns |
| smoothed normal (same as N but without bump) | |
| float | bu |
| barycentric coordinate (aka alpha, or u) | |
| float | bv |
| barycentric coordinate (aka beta, or v) | |
| float | u |
| U surface parameter. | |
| float | v |
| V surface parameter. | |
| uint32_t | fi |
| primitive ID (triangle, curve segment, etc) | |
| AtMatrix | M |
| local-to-world matrix transform | |
| AtMatrix | Minv |
| world-to-local matrix transform | |
| AtNode ** | lights |
| array of active lights at this shading context | |
| AtLightSample * | light_filter |
| light sample (for light filter shaders) | |
| uint32_t | nlights |
| number of active lights at this shading context | |
| AtVector | dPdu |
| surface derivative wrt U parameter | |
| AtVector | dPdv |
| surface derivative wrt V parameter | |
| AtVector | dDdx |
| ray direction derivative wrt screen X-axis | |
| AtVector | dDdy |
| ray direction derivative wrt screen Y-axis | |
| AtVector | dNdx |
| surface normal derivative wrt screen X-axis | |
| AtVector | dNdy |
| surface normal derivative wrt screen Y-axis | |
| float | dudx |
| U derivative wrt screen X-axis. | |
| float | dudy |
| U derivative wrt screen Y-axis. | |
| float | dvdx |
| V derivative wrt screen X-axis. | |
| float | dvdy |
| V derivative wrt screen Y-axis. | |
| bool | skip_shadow |
| if true, don't trace shadow rays | |
| uint8_t | sc |
| type of shading context | |
| bool | inclusive_traceset |
| is the trace-set inclusive? | |
| AtString | traceset |
| trace-set to assign to rays made from this SG | |
| AtParamValue | out |
| shader output | |
| AtShaderGlobalsPrivateInfo * | privateinfo |
| extra information for internal use | |
Shader globals data structure.
An AtShaderGlobals structure represents a shading context that holds all the information accesible to the different types of shaders. For example, after a camera ray hits the surface of an object, a shading context of type AI_CONTEXT_SURFACE is created that contains, amongst other things, local geometric properties such as the surface normal, the UV surface parameters, etc.
