rtcInterpolateN(3)

💖 rtcInterpolateN 💖

okay bestie, welcome to the rtcInterpolateN(3) page from the Embree Ray Tracing Kernels 3 era, and no, it's not the glow-up twin of rtcInterpolate — it's literally the same energy but it does N of them at once. the way that this function is just out here doing bulk interpolations like it's nothing?? iconic. ✨

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🌸 NAME 🌸

rtcInterpolateN — performs N interpolations of vertex attribute data

like. N. not one. N. slay. 💅

---

🎀 SYNOPSIS 🎀

#include <embree3/rtcore.h>

struct RTCInterpolateNArguments
{
  RTCGeometry geometry;
  const void* valid;
  const unsigned int* primIDs;
  const float* u;
  const float* v;
  unsigned int N;
  enum RTCBufferType bufferType;
  unsigned int bufferSlot;
  float* P;
  float* dPdu;
  float* dPdv;
  float* ddPdudu;
  float* ddPdvdv;
  float* ddPdudv;
  unsigned int valueCount;
};

void rtcInterpolateN(
  const struct RTCInterpolateNArguments* args
);

not me showing you the whole struct like it's a group chat screenshot 🫶 every field is exactly where it's supposed to be, don't touch them.

---

🦋 DESCRIPTION 🦋

so rtcInterpolateN is giving very much "rtcInterpolate but make it a batch". it's similar to rtcInterpolate, but instead of one lil interpolation it does N many interpolations at once. main character efficiency. 👑

and because it's doing the most, it also needs an array of u/v coordinates plus a valid mask (that's the valid parameter) that says which of those coordinates are actually valid. bestie, listen closely:

• the valid mask points to N integers
• a value of -1 means valid ✅
• a value of 0 means invalid ❌
• if the valid pointer is NULL, then all elements are considered valid (no cap)

the destination arrays get filled in structure of array (SOA) layout — so it's all lined up in its little rows, very organized, very demure. 🎀

⚠️ and the rule you CANNOT skip: the value N must be divisible by 4. not "should be". must. do the math before you ship it or it's over for you fr fr 😭

one more thing — if you wanna use rtcInterpolateN on a geometry, all changes to that geometry must be properly committed using rtcCommitGeometry. commit your changes, commit to the bit, commit to the geometry. that's the vibe check. 💅

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💀 EXIT STATUS 💀

for performance reasons this function does not do any error checks, so it will not set any error flags on failure.

🚨 translation: it is not going to hold your hand. no warnings, no error flags, nothing. if something goes wrong you get silence and vibes. check your own inputs, bestie, it's giving self-responsibility. 🙈

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🌈 SEE ALSO 🌈

• [rtcInterpolate]

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and that's the page!! 🎀 this whole thing lives in the Embree Ray Tracing Kernels 3 manual, under the name rtcInterpolateN(3), and yeah that's literally the same title as the header because manpages love symmetry. go interpolate something, but like, N of them. periodt. 💖✨🦋