rtcAttachGeometry(3)

💖 rtcAttachGeometry 💖

okay bestie, so this one's a page from the Embree Ray Tracing Kernels 3 manual, and it's genuinely one of the most iconic little functions you'll ever meet. it's called rtcAttachGeometry and its whole job? attaching a geometry to the scene. that's it. that's the vibe. 🎀

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✨ NAME ✨

rtcAttachGeometry — attaches a geometry to the scene 🫶

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🌸 SYNOPSIS 🌸

#include <embree3/rtcore.h>

unsigned int rtcAttachGeometry(
  RTCScene scene,
  RTCGeometry geometry
);

like, look at that signature. it's giving "short and powerful". 💅

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🦋 DESCRIPTION 🦋

so what does rtcAttachGeometry actually do? it takes a geometry (that's the geometry argument, bestie) and attaches it to a scene (that's the scene argument), and in return it hands that geometry a geometry ID. simple as that. ✨

every geometry you attach to a scene is defined to be included inside the scene. no cap. and here's the fun part: one geometry can get attached to multiple scenes at the same time. she's versatile like that. 💅

the geometry ID is unique for the scene, and it's what you use to identify which geometry got hit by a ray during ray queries. so like, that ID is the whole point — it's how you find out who got hit. 🔥

thread-safe alert!! this function is thread-safe, which means multiple threads can attach geometries to a scene in parallel. go off, multithreading. 👑

now, the ID assignment rules, and you need these because they're lowkey the whole tea:

• geometry IDs are assigned sequentially, starting from 0, as long as no geometry got detached.
• but if geometries did get detached, the implementation will reuse IDs in an implementation dependent way. so consequently, sequential assignment is no longer guaranteed — instead you get a compact range of IDs. still cute, just not in order. 😭

these rules are genuinely there to help you: they allow the application to manage a dynamic array to efficiently map from geometry IDs to its own geometry representation. iconic design, honestly. alternatively, the application can also use per-geometry user data to map to its geometry representation — see rtcSetGeometryUserData and rtcGetGeometryUserData for more info. iykyk. 🌈

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💀 EXIT STATUS 💀

if something goes wrong? on failure an error code is set, and you can go query it using rtcGetDeviceError. so don't just sit there wondering bestie, go check it. 🍓

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⭐ SEE ALSO ⭐

• [rtcSetGeometryUserData]
• [rtcGetGeometryUserData]

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and that's the whole page, fr fr. this was rtcAttachGeometry(3) from the Embree Ray Tracing Kernels 3 manual — go attach something, you're gonna slay. 💖✨🧚

rtcAttachGeometry(3) · Embree Ray Tracing Kernels 3 · mwah, bye bestie 🎀