Calling volumetric function with cameras from ImplicitRenderer

[YanivHollander]

The method forward in class ImplicitRenderer calls on line 168 the volumetric_function model with cameras as an input argument. The forward of volumetric_function (in class NeuralRadianceFieldm, e.g.) does not have cameras in its API, nor does it need it. Rays are already well defined at this point, and the volumetric function can return opacity and features along the rays, without the need for the camera objects that were used to sample the rays.

Please advise, and if needed I will create an issue on this.

[bottler]

ImplicitRenderer is generic - designed to work with many different raysamplers, volumetric functions, and raymarchers. In general, implementations of these all need to ignore extra keyword arguments. You could imagine a use case where the volumetric function needs the cameras, so we provide it. The NeRF project is just an example of the use of ImplicitRenderer which doesn't use it. This isn't a bug.