Frustum Culling is a test, if a position is in front of the camera and within the field of view.
My version of this creates a normal vector for each plane of the frustum and transforms it with the camera.
The dot product of a vector from the camera to a point in space, and each of the normal vectors tells me, if the point is inisde the frustum.
This simple version does not take aspect ratio into account:
Download the blendfile of this setup.
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