RTCSETGEOMETRYVERTEXATTRIBUTETOPOLOGY(3embree4)

💖 rtcSetGeometryVertexAttributeTopology 💖

okay so bestie, you found it — the rtcSetGeometryVertexAttributeTopology page from the Embree Ray Tracing Kernels 4 manual (that's 3embree4 to the librarians, iykyk). it's giving very niche, very powerful, very "binds a vertex attribute to a topology of the geometry." let's get into it 🦋

✨ NAME ✨

rtcSetGeometryVertexAttributeTopology — binds a vertex attribute to a topology of the geometry 💅

✨ SYNOPSIS ✨

#include <embree4/rtcore.h>

void rtcSetGeometryVertexAttributeTopology(
  RTCGeometry geometry,
  unsigned int vertexAttributeID,
  unsigned int topologyID
);

✨ DESCRIPTION ✨

so here's the tea, bestie 🫖 the rtcSetGeometryVertexAttributeTopology function binds a vertex attribute buffer slot (that's your vertexAttributeID argument, bestie, remember her) to a topology (that's your topologyID argument, queen) for the subdivision geometry you picked out (that's the geometry argument, the main character of this whole operation).

now — and this is important — standard vertex buffers are always bound to the default topology (topology 0) and literally cannot be bound any differently. no cap. that's just how they live. 🔒

a vertex attribute buffer, though? she always uses the topology she's bound to whenever she shows up in rtcInterpolate and rtcInterpolateN calls. periodt. 💖

and a topology with ID i? let me break it down, it consists of:

• a subdivision mode, set through rtcSetGeometrySubdivisionMode 🌸
• the index buffer bound to the index buffer slot i 🎀

this index buffer can assign indices for each face of the subdivision geometry that are different to the indices of the default topology. iconic, honestly. and those new indices can, for example, be used to introduce additional borders into the subdivision mesh so you can map multiple textures onto one subdivision geometry. the way that's so useful?? obsessed. ✨

✨ EXIT STATUS ✨

if it goes wrong, an error code gets set — and you can go query it using rtcGetDeviceError. go check on her, she'll tell you what happened 😭

✨ SEE ALSO ✨

• rtcSetGeometrySubdivisionMode
• rtcInterpolate
• rtcInterpolateN

and that's the whole page, bestie 💜 straight from the Embree Ray Tracing Kernels 4 manual, rtcSetGeometryVertexAttributeTopology(3) section, no date on this one but the version's right there in the name — go forth and bind those topologies, you've got this 👑🌈⭐