Troubleshooting artifacts

I’m encountering a patterned artifact when running a particular batch of photos, roughed up geometry in which the color of these bumps seems to hold a clue what’s causing it. I’m attaching screen captures taken from within various programs that illustrate the problem and provide valuable clues. “3DS01” is from 3DS Max in facet view, shows the bumpiness, “3DS02” is in flat color mode, and shows these bumps on the caver’s green pants, red top, arm, etc. being colored the same as the background rock. It seems the photogrammetry engine is producing features with high residuals and somehow figuring these in throughout the mesh. Though they show up most pronounced in the caver because of contrasting color and our bias knowing what a human should look like, they’re probably peppered throughout the rock as well.

“Remake01” shows a reconstruction from the same photos and without these artifacts. “Remake02” shows the wireframe, clearly with far fewer triangles than the solution from RC, which you see in “3DS03” is largely quite dense. “Orig” is a sample of the source photography. Note, it does feature noticeable grain, this after 50% denoising with NIK D’Fine. I had tried these same photos with sharpening and no noise reduction, saw the bumpiness and figured that sharpening the grain may have been causing the problem. Noise reduction actually made the problem worse. Also to note, “Orig” is a crop from a 52 Mp image, the caver was often a good 3 m away, and to maintain adequate exposure with cross-polarization, I had to bump ISO to 1600. Clearly, I need to get closer to the subject with more photos at lower ISO if I value fidelity in the mesh. That said, the reconstruction in Remake is quite acceptable, at least in terms of not featuring these artifacts, if only in those terms. “RC_scene” shows my setup, my question being 1) if I’m seeing the problem correctly as related to the monochromatic and shadow-free rock not providing RC enough to go on for feature detection, and 2) if there’s not some setting I could change to possibly move RC’s solution in the direction of what Remake was able to deliver.


Hi Benjamin von Cramon

Can you contact me directly on my email and send the whole dataset + RCPROJ data with description to me ?