In one embodiment, a computing system accesses a three-dimensional (3D) model of an environment, the 3D model comprising a virtual representation of an object in the environment. The computing system accesses an image of the object captured by a camera from a camera pose. The computing system accesses light source parameters associated with a virtual representation of a light source in the environment. The computing system renders, using the 3D model, pixels associated with the virtual representation of the object based on the light source parameters, the pixels being rendered from a virtual perspective corresponding to the camera pose. The computing system determines updated light source parameters based on a comparison of the rendered pixels to corresponding pixels located in the image of the object.