rtcGetGeo...FromScene(3)

✨ rtcGetGeo...FromScene(3) ✨

okay bestie, sit down, hydrate, and let me tell you about rtcGetGeometryTransformFromScene from the Embree Ray Tracing Kernels 4 era 💖 (yes the page name is abbreviated, that's just how it is, she's mysterious like that 🎀)

🌸 NAME 🌸

rtcGetGeometryTransformFromScene — returns the interpolated instance transformation for the specified time 🕰️✨

🦋 SYNOPSIS 🦋

#include <embree4/rtcore.h>

void rtcGetGeometryTransformFromScene(
  RTCScene scene,
  unsigned int geomID,
  float time,
  enum RTCFormat format,
  void* xfm
);

💅 DESCRIPTION 💅

so like, the rtcGetGeometryTransformFromScene function returns the interpolated local to world transformation (that's your xfm output parameter, she's the main character here 👑) of an instance geometry. which instance geometry tho? the one specified by its geometry ID — that's the geomID parameter 💖 — inside a scene (the scene parameter, duh) for a particular time (the time parameter, and she lives in the range [0, 1] fr fr) in the specified format (the format parameter ✨).

the possible formats for the returned matrix are, and listen closely because this matters:

• RTC_FORMAT_FLOAT3X4_ROW_MAJOR — the 3×4 float matrix is laid out in row-major form 🌈
• RTC_FORMAT_FLOAT3X4_COLUMN_MAJOR — the 3×4 float matrix is laid out in column-major form 💜
• RTC_FORMAT_FLOAT4X4_COLUMN_MAJOR — the 3×4 float matrix is laid out in column-major form as a 4×4 homogeneous matrix, with the last row equal to (0, 0, 0, 1) 🍓

and now the plot twist that makes her iconic: in contrast to the rtcGetGeometryTransform function, rtcGetGeometryTransformFromScene can get used during rendering inside a SYCL kernel 🔥 that's the whole point of her existence, no cap.

😭 EXIT STATUS 😭

on failure, an error code is set — and you can query it using rtcGetDeviceError 🙈

💀 SEE ALSO 💀

• [RTC_GEOMETRY_TYPE_INSTANCE]
• [rtcSetGeometryTransform]
• [rtcGetGeometryTransform]

go read those too, bestie, they're giving family reunion energy 🫶

Embree Ray Tracing Kernels 4 ✨ page rtcGetGeo...FromScene(3) ✨ and that's the whole tea, thanks for coming to my ted talk, mwah 💖🎀🦋🌸👑