Gravel - Photogrammetry based Environment Texture
Another gravel surface I turned into PBR material using photogrammetry.
This capture was done as part of the experiment with focal length settings and cameras mounts.
Similar to the previous capture I mounted the camera as high as possible but set the focal length to 24mm. It gave me larger surface coverage per shot compared to the one with 90 degree angled arm. In result I took 58 images in total to cover entire area (just to compare, I took 129 last time to cover similar area but with the focal length set to 35mm). In result the capture took twice less time compared to the previous one but amount and quality of captured data is questionable.
Lessons learned: 35mm focal length and perpendicular to the surface camera mount seems to be the best choice. 24 mm setting for flat surfaces like this one is still an option to consider but at cost of quality loss and I would suggest to avoid it while scanning a bit more complex surface types.
This is my photogrammetry workflow - still experimenting with 'Artomatix' and replaced Photoscan with Metashape (more details regarding to my workflow at: https://www.artstation.com/artwork/K0PYG). Btw. today my ebook received a 33rd update :D
The source - this time to get as much coverage per image as possible without any meaningful distortions I mount the camera as high as possible and set the focal length to 25mm. In result to fully cover the area marked with green I took 58 images.
The Source - surface details with my shoe and ruler used as scale reference.
The reference image with the Color Checker I used to calibrate colors in PhotoLab2
Metashape reconstruction preview - Since I mount the camera higher, to remove tripods legs from the frame view I had to set the angle to be less perpendicular to the surface
Metashape - reconstruction details preview.
ZBrush - lowpoly coverage over highpoly scan - I covered 180x180cm of real space
Artengine Artomatix in action - in 2D view I masked areas I wanted to be skipped by AI during seam removal and texture reconstruction. I also used GRADIENT REMOVAL node to calm down color differences within the surface and make tiling less noticeable
The final PBR material preview in 1k resolution