---
name: "RTCHit"
section: "3"
platform: "linux"
package: "libembree-dev"
version: "4.3.3+dfsg-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/RTCHit"
---

# RTCHit(3)

### NAME

-

  ```
  RTCHit - single hit structure
  ```

### SYNOPSIS

-

  ```
  #include <embree4/rtcore.h>
  struct RTCHit
  {
    float Ng_x;                                        // x coordinate of geometry normal
    float Ng_y;                                        // y coordinate of geometry normal
    float Ng_z;                                        // z coordinate of geometry normal
    float u;                                           // barycentric u coordinate of hit
    float v;                                           // barycentric v coordinate of hit
    unsigned int primID;                               // geometry ID
    unsigned int geomID;                               // primitive ID
    unsigned int instID[RTC_MAX_INSTANCE_LEVEL_COUNT]; // instance ID
  };
  ```

### DESCRIPTION

The `RTCHit` type defines the type of a ray/primitive intersection result. The hit contains the unnormalized geometric normal in object space at the hit location (`Ng_x`, `Ng_y`, `Ng_z` members), the barycentric u/v coordinates of the hit (`u` and `v` members), as well as the primitive ID (`primID` member), geometry ID (`geomID` member), and instance ID stack (`instID` member) of the hit. The parametric intersection distance is not stored inside the hit, but stored inside the `tfar` member of the ray.

The `embree4/rtcore_ray.h` header additionally defines the same hit structure in structure of array (SOA) layout for hit packets of size 4 (`RTCHit4` type), size 8 (`RTCHit8` type), and size 16 (`RTCHit16` type). The header additionally defines an `RTCHitNt` template for hit packets of an arbitrary compile-time size.

### EXIT STATUS

### SEE ALSO

\[RTCRay\], \[Multi-Level Instancing\]