RTCSETGEOMETRYTIMESTEPCOUNT(3)

✨ rtcSetGeometryTimeStepCount ✨

okay so bestie, you're in the Embree Ray Tracing Kernels 4 manual, section 3, and today's main character is rtcSetGeometryTimeStepCount 🎀. yes it's a mouthful. yes it's iconic. let's go 💅

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🌸 NAME 🌸

rtcSetGeometryTimeStepCount — sets the number of time steps of the geometry 🦋

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✨ SYNOPSIS ✨

#include <embree4/rtcore.h>

void rtcSetGeometryTimeStepCount(
  RTCGeometry geometry,
  unsigned int timeStepCount
);

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💖 DESCRIPTION 💖

so rtcSetGeometryTimeStepCount sets the number of time steps for multi-segment motion blur — that's the timeStepCount parameter, bestie — for the geometry you point at with the geometry parameter. it's giving "how many snapshots of this thing exist in time" energy 🕰️✨

now here's where it gets type-dependent, and honestly? the way each geometry type handles this is so different, pay attention 🙈

• for triangle meshes (RTC_GEOMETRY_TYPE_TRIANGLE), quad meshes (RTC_GEOMETRY_TYPE_QUAD), curves (RTC_GEOMETRY_TYPE_CURVE), points (RTC_GEOMETRY_TYPE_POINT), and subdivision geometries (RTC_GEOMETRY_TYPE_SUBDIVISION), the number of time steps directly corresponds to the number of vertex buffer slots available (RTC_BUFFER_TYPE_VERTEX buffer type). so for these ones, you must specify one vertex buffer per time step when you're creating multi-segment motion blur geometries. one buffer per step, no skipping, periodt 💀
• for instance geometries (RTC_GEOMETRY_TYPE_INSTANCE), a transformation must be specified for each time step — go peek at rtcSetGeometryTransform for that 🫶
• for user geometries, the registered bounding callback function must provide a bounding box per primitive and per time step, and the intersection and occlusion callback functions should properly intersect the motion-blurred geometry at the ray time. yes both. yes at the ray time. iykyk 🔥

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💀 EXIT STATUS 💀

on failure an error code is set that can be queried using rtcGetDeviceError. so if something's off, go ask rtcGetDeviceError what happened, she'll tell you 💅

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👑 SEE ALSO 👑

• [rtcNewGeometry]
• [rtcSetGeometryTimeRange]

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and that's the whole page bestie, no notes 💖 you just read the rtcSetGeo...eStepCount(3) page out of the Embree Ray Tracing Kernels 4 manual, so go forth, set those time step counts, and slay 🌈⭐ mwah 🫶