Correct! Currently i am repeating the same scan several times as you mentioned.
1. First turntable scan with e.g. 8 scans + texture.
Exposure, Gain, Projector optimized for mesh scanning.
But also texture is captured, which will be later replaced with offline created HDR image.
(Optional: If object has light and dark areas it might be needed to perform another turntable scan with higher exposure, gain and projector settings to also capture mesh from dark areas. This time the texture should be disabled. Later this second scan need to be aligned with first round and moved to the first project folder. Unfortunately MAF3 does not have HDR for point cloud capturing as many other structured light scanner have. So this workaround could be used.)
2. Second turntable scan without moving the object. First HDR image (normal exposure).
Exposure, Gain optimized for white/light area (no red indication indicating overexposure).
Projector set to zero, external light switched on.
3. Third turntable scan without moving the object. Second HDR image (overexposed).
Exposure, Gain optimized for black/dark area. Light areas are extremely overexposed.
Projector set to zero, external light switched on.
4. Fourth turntable scan without moving the object. Third HDR image (middle between normal/overexposed).
Exposure, Gain set to the middle of the values normal/overexposed.
Projector set to zero, external light switched on.
Same procedure to be repeated for another set of capture poses. E.g. Top/Bottom or Top/Left/Right
Afterwards exporting the whole project (zip file) and creating HDR images using SNS-HDR Lite (Free Version) with batch processing. Only texture-0 (image from left camera) need to be processed because right image not used for texturing. The created HDR image will be used to replace the normal image from mesh scanning. Finally importing the modified zip file into MAF3 and create texture with new HDR images.
For the moment this is the easiest manual procedure. If scan spray is needed (e.g. glass, clear acrylic, shiny, glossy, black object) then it's better to do first the HDR image capturing, then apply the scan spray and do the mesh scan at the end. Some self-evaporating scanning spray (e.g. AESUB blue) will disappear in 1-2h and next scanning pose can be done. By this best quality for mesh and texture can be achieved especially for objects with challenging surface.
Another (better) procedure would be capture mesh scan, and texture images one after each other for every position. This is faster and more robust for inaccuracy of turntable movement and also better method when doing single short without turntable.
Example from my windows batch file to create HDR images:
REM Set path to SNS-HDR lite!
set SNSHDR="C:\Program Files\SNS-HDR Lite 2\SNS-HDR.exe"
echo Start to generate HDR images! Existing images will be overwritten!
%SNSHDR% -da -dd -x1 -dramatic .\Scan-7\Textures\Texture-0.png .\Scan-13\Textures\Texture-0.png .\Scan-19\Textures\Texture-0.png -o .\Scan-1\Textures\Texture-0.png
%SNSHDR% -da -dd -x1 -dramatic .\Scan-8\Textures\Texture-0.png .\Scan-14\Textures\Texture-0.png .\Scan-20\Textures\Texture-0.png -o .\Scan-2\Textures\Texture-0.png
%SNSHDR% -da -dd -x1 -dramatic .\Scan-9\Textures\Texture-0.png .\Scan-15\Textures\Texture-0.png .\Scan-21\Textures\Texture-0.png -o .\Scan-3\Textures\Texture-0.png
%SNSHDR% -da -dd -x1 -dramatic .\Scan-10\Textures\Texture-0.png .\Scan-16\Textures\Texture-0.png .\Scan-22\Textures\Texture-0.png -o .\Scan-4\Textures\Texture-0.png
%SNSHDR% -da -dd -x1 -dramatic .\Scan-11\Textures\Texture-0.png .\Scan-17\Textures\Texture-0.png .\Scan-23\Textures\Texture-0.png -o .\Scan-5\Textures\Texture-0.png
%SNSHDR% -da -dd -x1 -dramatic .\Scan-12\Textures\Texture-0.png .\Scan-18\Textures\Texture-0.png .\Scan-24\Textures\Texture-0.png -o .\Scan-6\Textures\Texture-0.png
