How to Fix 3D Scan "Blobiness" in postprocess?
polycounter lvl 9
Hello, im playing around with photogrammetry, 3D scans, using agisoft photoscan for scanning various objects for 3D, mostly smaller objects (the size from size of shoe box to size of a chair, nothing bigger so far), but a lot of the scans suffer from blobiness, it doesnt look really realistic, i cannot show my work, but for example this is what i call "blobiness" random from net:
http://postimg.org/image/ivm3d5npb/
http://postimg.org/image/d25vr0wk1/
http://postimg.org/image/42rdds5o5/
How to fix this IN POSTPROCESS, i have a lot of photos already and cannot take them again, so trying to play with depth of field etc. cannot be done, i know that the blobiness has a lot to do with depth of field (im shooting on tripod, F8-F11, 35-55mm Nikon D3200, default lense).
How to fix this when the photos are already taken? I tried to change in photoscan- Depth filtering from agressive to mild, and it helps but really only a BIT. Tried to go from medium dense point cloud detail generation to high, DIDNT help either.
The only thing that pops up in my mind is (how to fix ot at leats help it a little is: Is there some "sharpening" brush in sculpting sofrwares (zbrush)? Which will work like the opposite of "smooth" brush, that means it will "sharpen" the edges instead of smooting them? That might help... Im tired of the blobiness of the scans even when the scan comes out "good" its still blobby...
Is there such "sharpening" brush in zbrush? How to fight the mesh "blobiness" in postprocessing of the scan? (when photos are already taken)?
http://postimg.org/image/ivm3d5npb/
http://postimg.org/image/d25vr0wk1/
http://postimg.org/image/42rdds5o5/
How to fix this IN POSTPROCESS, i have a lot of photos already and cannot take them again, so trying to play with depth of field etc. cannot be done, i know that the blobiness has a lot to do with depth of field (im shooting on tripod, F8-F11, 35-55mm Nikon D3200, default lense).
How to fix this when the photos are already taken? I tried to change in photoscan- Depth filtering from agressive to mild, and it helps but really only a BIT. Tried to go from medium dense point cloud detail generation to high, DIDNT help either.
The only thing that pops up in my mind is (how to fix ot at leats help it a little is: Is there some "sharpening" brush in sculpting sofrwares (zbrush)? Which will work like the opposite of "smooth" brush, that means it will "sharpen" the edges instead of smooting them? That might help... Im tired of the blobiness of the scans even when the scan comes out "good" its still blobby...
Is there such "sharpening" brush in zbrush? How to fight the mesh "blobiness" in postprocessing of the scan? (when photos are already taken)?
Replies
what's the 'blob-ness' you are referring to exactly? are you talking about the general surface noise and lack of definition and rounded corners everywhere? that looks more like the picture quality you are getting or the scan software's processing of it has hit the limits. are you processing at maximum resolution?
try out the flatten and polish brushes in zbrush. pinch might also come in handy to define corners but can introduce it's own flavour of artifacts if used excessively.
perhaps you can find a decent way of masking those corners by using mask by peaks&vallyes from the masking palette, then run the polish function found in the deformation palette.
That blobiness you're seeing could be coming from the photos (maybe) - sometimes if a photo has any noise in it, Photoscan will accidentally track that noise as an actual point in space.
You might also need more photos to overlap around those troubled areas? Just in case it's having trouble working out where certain points are...
Setting your Dense Point cloud generation to "Aggressive" is a nice easy way to create a smooth mesh with the noisiness carved off. Trying a Photo alignment step using the Medium step is another cheap was to smooth your results (doesn't always work, but worth a try).
Trying lower tie point values could help?
Another thing you could try, is once you've done your alignment, go to "Edit>Gradual selection," and play with the values in there - deleting any points that Photoscan flags as being less than acceptable.
After you've done that, make another dense point cloud (aggressive), and see how it looks. You can manually delete any points you feel might be ruining the results.
When you reproject in ZBrush, start with a low poly mesh, reproject, do any smoothing of artifacts that you see, then subdivide, reproject, smooth, and repeat as you go up each level of subdivision.
Once you're happy with the model, you could import your new model back into Photoscan and regenerate the textures onto the new model.
Those are some things I can think of anyway. Let me know how you go ^_^