---
name: "rtcSetGeometryTransform"
section: "3embree4"
platform: "linux"
package: "embree"
version: "4.4.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/rtcSetGeometryTransform/3embree4"
---

# rtcSetGeometryTransform(3embree4)

### NAME

-

  ```
  rtcSetGeometryTransform - sets the transformation for a particular
    time step of an instance geometry
  ```

### SYNOPSIS

-

  ```
  #include <embree4/rtcore.h>
  void rtcSetGeometryTransform(
    RTCGeometry geometry,
    unsigned int timeStep,
    enum RTCFormat format,
    const float* xfm
  );
  ```

### DESCRIPTION

The `rtcSetGeometryTransform` function sets the local-to-world affine transformation (`xfm` parameter) of an instance geometry (`geometry` parameter) for a particular time step (`timeStep` parameter). The transformation is specified as a 3×4 matrix (3×3 linear transformation plus translation), for which the following formats (`format` parameter) are supported:

- •

  `RTC_FORMAT_FLOAT3X4_ROW_MAJOR`: The 3×4 float matrix is laid out in row-major form.

- •

  `RTC_FORMAT_FLOAT3X4_COLUMN_MAJOR`: The 3×4 float matrix is laid out in column-major form.

- •

  `RTC_FORMAT_FLOAT4X4_COLUMN_MAJOR`: The 3×4 float matrix is laid out in column-major form as a 4×4 homogeneous matrix with the last row being equal to (0, 0, 0, 1).

### EXIT STATUS

On failure an error code is set that can be queried using `rtcGetDeviceError`.

### SEE ALSO

\[RTC\_GEOMETRY\_TYPE\_INSTANCE\]