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

# rtcSetGeometryOccludedFilterFunction(3)

### NAME

-

  ```
  rtcSetGeometryOccludedFilterFunction - sets the occlusion filter
    for the geometry
  ```

### SYNOPSIS

-

  ```
  #include <embree4/rtcore.h>
  void rtcSetGeometryOccludedFilterFunction(
    RTCGeometry geometry,
    RTCFilterFunctionN filter
  );
  ```

### DESCRIPTION

The `rtcSetGeometryOccludedFilterFunction` function registers an occlusion filter callback function (`filter` argument) for the specified geometry (`geometry` argument).

Only a single callback function can be registered per geometry, and further invocations overwrite the previously set callback function. Passing `NULL` as function pointer disables the registered callback function.

The registered occlusion filter function is invoked for every hit encountered during the `rtcOccluded`-type ray queries and can accept or reject that hit. The feature can be used to define a silhouette for a primitive and reject hits that are outside the silhouette. E.g. a tree leaf could be modeled with an alpha texture that decides whether hit points lie inside or outside the leaf.

Please see the description of the `rtcSetGeometryIntersectFilterFunction` for a description of the filter callback function.

The `rtcOccluded`-type functions terminate traversal when a hit got committed. As filter functions can only set the `tfar` distance of the ray for a committed hit, the occlusion filter cannot influence the `tfar` value of subsequent traversal, as that directly ends. For that reason `rtcOccluded` and occlusion filters cannot get used to gather the next n-hits, and `rtcIntersect` and intersection filters should get used instead.

### EXIT STATUS

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

### SEE ALSO

\[rtcSetGeometryIntersectFilterFunction\]