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

# rtcSetGeometryTimeStepCount(3)

### NAME

-

  ```
  rtcSetGeometryTimeStepCount - sets the number of time steps of the
    geometry
  ```

### SYNOPSIS

-

  ```
  #include <embree4/rtcore.h>
  void rtcSetGeometryTimeStepCount(
    RTCGeometry geometry,
    unsigned int timeStepCount
  );
  ```

### DESCRIPTION

The `rtcSetGeometryTimeStepCount` function sets the number of time steps for multi-segment motion blur (`timeStepCount` parameter) of the specified geometry (`geometry` parameter).

For triangle meshes (`RTC_GEOMETRY_TYPE_TRIANGLE`), quad meshes (`RTC_GEOMETRY_TYPE_QUAD`), curves (`RTC_GEOMETRY_TYPE_CURVE`), points (`RTC_GEOMETRY_TYPE_POINT`), and subdivision geometries (`RTC_GEOMETRY_TYPE_SUBDIVISION`), the number of time steps directly corresponds to the number of vertex buffer slots available (`RTC_BUFFER_TYPE_VERTEX` buffer type). For these geometries, one vertex buffer per time step must be specified when creating multi-segment motion blur geometries.

For instance geometries (`RTC_GEOMETRY_TYPE_INSTANCE`), a transformation must be specified for each time step (see `rtcSetGeometryTransform`).

For user geometries, the registered bounding callback function must provide a bounding box per primitive and time step, and the intersection and occlusion callback functions should properly intersect the motion-blurred geometry at the ray time.

### EXIT STATUS

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

### SEE ALSO

\[rtcNewGeometry\], \[rtcSetGeometryTimeRange\]