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

# rtcGetGeometryTransformEx(3embree4)

### NAME

-

  ```
  rtcGetGeometryTransformEx - returns the interpolated instance
  transformation for an instance of an instance array geometry for the
  specified time.
  ```

### SYNOPSIS

-

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

### DESCRIPTION

The `rtcGetGeometryTransformEx` function returns the interpolated local to world transformation (`xfm` parameter) of the `instPrimID`-th instance of an instance array geometry (`geometry` parameter) for a particular time (`time` parameter in range \[0, 1\]) in the specified format (`format` parameter). The function can also be used when `geometry` refers to a regular instance, but then the `instPrimID` has to be 0.

Possible formats for the returned matrix are:

- •

  `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 last row equal to (0, 0, 0, 1).

### EXIT STATUS

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

### SEE ALSO

\[RTC\_GEOMETRY\_TYPE\_INSTANCE\_ARRAY\]