Post-processing in a lidar system may be guided by camera information as described herein. In one embodiment, a camera system has a camera to capture images of the scene. An image processor is configured to classify an object in the images from the camera. A lidar system generates a point cloud of the scene and a modeling processor is configured to correlate the classified object to a plurality of points of the point cloud and to model the plurality of points as the classified object over time in a 3D model of the scene.