Are both TIFFs and DNG (Apple ProRAW format) currently not supported?
this was just answered for me during the Apple Object Capture developer session so I'll post it here for everyone to see:
The API accepts images with CVPixelBuffer with format kCVPixelFormatType_32BGRA and kCVPixelFormatType_32ARGB. So if you can load the images and convert to the required format, then the engine should be abe to process. see https://developer.apple.com/documentation/realitykit/photogrammetrysample and https://developer.apple.com/documentation/realitykit/photogrammetrysample/3788297-image