rtcAttachGeometry(3)

💖 rtcAttachGeometry(3) — Embree Ray Tracing Kernels 4 💖

okay bestie, gather round, because this one is genuinely so cute and so important. it's rtcAttachGeometry, and yes, it does exactly what it says on the tin: it attaches a geometry to the scene. no cap. let's get into it 🫶

✨ NAME ✨

rtcAttachGeometry — attaches a geometry to the scene

🌸 SYNOPSIS 🌸

#include <embree4/rtcore.h>

unsigned int rtcAttachGeometry(
  RTCScene scene,
  RTCGeometry geometry
);

🦋 DESCRIPTION 🦋

so like, the way that rtcAttachGeometry works is it takes a geometry (that's the geometry argument, bestie, keep up 💅) and attaches it to a scene (that's the scene argument, iconic). and in doing that, it assigns a geometry ID to that geometry. slay.

every single geometry that's attached to a scene is defined to be included inside the scene. and here's the fun part: a geometry can get attached to multiple scenes. she's versatile like that, main character energy fr fr ✨. the geometry ID is unique for the scene, and it's the thing that identifies the geometry when it gets hit by a ray during ray queries. iykyk.

not me about to tell you this function is thread-safe — because it literally is, so multiple threads can attach geometries to a scene in parallel. go off, multithreading 👑

okay so here's the ID lore, because it actually matters:

• geometry IDs get assigned sequentially, starting from 0, as long as no geometry got detached. clean, tidy, gorgeous.
• but if geometries got detached? the implementation will reuse IDs in an implementation dependent way 🙈. so sequential assignment is no longer guaranteed — but you still get a compact range of IDs. so it's not chaos, it's just... vibes.

these rules exist so the application can manage a dynamic array to efficiently map from geometry IDs to its own geometry representation. and if that's not your thing, you can also use per-geometry user data to map to its geometry representation instead. your choice, bestie, both are valid 💜. see rtcSetGeometryUserData and rtcGetGeometryUserData for more info.

💀 EXIT STATUS 💀

on failure, an error code is set that can be queried using rtcGetDeviceError. so if something goes sideways, that's your girl. go ask her what happened 😭

🎀 SEE ALSO 🎀

• [rtcSetGeometryUserData]
• [rtcGetGeometryUserData]

lowkey a reminder: the whole "sequential IDs from 0" thing only holds while nothing's been detached. the second something gets detached, all bets are off and the IDs get recycled in an implementation dependent way. not a bug, just the rules 💅

kisses, and this was rtcAttachGeometry(3) from Embree Ray Tracing Kernels 4 🧚 — now go attach something iconic and have the best day ever, mwah 💖