Applying filters to custom objects in an image

I would like to create an application that adds image filters (Snapchat-style) to photos of cats or chairs (just for the sake of this question). In order to do that properly, I thought of using Active Shape Modelling algorithms to have a model to apply the filters to.

I trained an object detection model to identify those items in an image (yolov5), so I now have a bounding box around each item, but I still don't know its exact shape of orientation.

How would I continue this work, so that I can attach a precise filter to each cat or chair?