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You're sort of lost me - I too do work and research in this field, and I have never seen the question "Do we 3D model or 3D scan this?", treating them as comple

by 542458 10y ago

You're sort of lost me - I too do work and research in this field, and I have never seen the question "Do we 3D model or 3D scan this?", treating them as completely interchangeable. Can you give an example of a domain or application where that is true? The point of my examples was that scanning is currently so limited as to make a pure scanning workflow unworkable in almost all situations, including this one. Scanning is incapable of doing what modelling can (good topo, clean results, accurate representations of translucent, reflective, etc surfaces). Likewise, modelling is incapable of doing what scanning can (quick approximate real-world captures). They're different tools that accomplish different things. > In fact photogrammetry and laser scanning is getting to the point of eclipsing hand modeling for pretty much anything that is not a result of a CAD model. Due to differing definitions of what is considered "CAD" I'm not sure what you mean by this. I can think of applications where 3D scans are used, but only either as a reference for hand-modelling, or only after being so heavily hand corrected that it's a really more of a hybrid (model/scan) process. Animation almost always uses hand-modelled or heavily corrected (by hand) scans. Manufacturing uses hand-modelled objects or traced-over scans. Gaming uses hand-modelled objects or traced-over scans. Where are scans eclipsing hand 3D modelling? They're being used but as a different part of a hybrid workflow.

AndrewKemendo 10y ago
Well in our case we use models of furnishings. The space of furnishings is so large that you can't hand model everything manually in polynomial time (that's a joke). As a result we have clients that want 7 million objects in 3D. So we had to figure out how we were going to build a massive model repo quickly and at high enough resolution to be good enough for rendering. Scanning is the only way to do that so we built an entirely new way to do that combining the latest photogrammetry and depth scanning research. Going further, with already built things, that aren't previously built in CAD, like components and old buildings, in solidworks autocad etc... Making those models is much more efficient with structured light or photogrammetry systems. It should be noted that it's not just speed, it's hard to model to micron specificity, whereas we can with scanning. Animation is a little different but I think follows the same principles in the long run. The distinction between the methods in my mind is between digitizing something real versus making something new. I think in the former case scanning will win long term.
- 542458 10y ago
  Okay, so you're creating many approximate representations of opaque and (mostly) rigid real world objects, and don't care about surface topology, rigging or UV layout. Using raw scan data works for that highly specific workflow, but let me assure you that for the overwhelming majority of the various 3D industries this is not the case. > Making those models is much more efficient with structured light or photogrammetry systems Only if you don't care about topology, representing unscannable things, polygon efficiency, UV layout, rigging, etc etc etc. For animation it's nowhere near competitive at present - you basically have to resculpt or retopo everything for anything but static matte background props. Maybe long-run pure scanning workflows will become more competitive, but that's not what my comment was about.
  - AndrewKemendo 10y ago
    and don't care about surface topology, rigging or UV layout Not true. In fact those are important aspects - especially UV layout as texture baking correctly across dynamic finishes with the same underlying polygons is critical for accurate rendering. majority of the various 3D industries Like which? Aside from production level CAD/CAM we cover most other use cases as they are almost strictly rendering/modeling. Only if you don't care about topology, representing unscannable things, polygon efficiency, UV layout, rigging Again, not true. Especially polygon efficiency - our model requires polygon optimization so that our models can be utilized by low-bandwidth areas. It has been a massive challenge but one we cracked big nuts on. "Unscannable things" is an issue, but again, there are solutions including destructive scanning and X-Ray/MRI which give us insight.

by 542458 10y ago

AndrewKemendo 10y ago

Well in our case we use models of furnishings. The space of furnishings is so large that you can't hand model everything manually in polynomial time (that's a joke). As a result we have clients that want 7 million objects in 3D. So we had to figure out how we were going to build a massive model repo quickly and at high enough resolution to be good enough for rendering. Scanning is the only way to do that so we built an entirely new way to do that combining the latest photogrammetry and depth scanning research. Going further, with already built things, that aren't previously built in CAD, like components and old buildings, in solidworks autocad etc... Making those models is much more efficient with structured light or photogrammetry systems. It should be noted that it's not just speed, it's hard to model to micron specificity, whereas we can with scanning. Animation is a little different but I think follows the same principles in the long run. The distinction between the methods in my mind is between digitizing something real versus making something new. I think in the former case scanning will win long term.

542458 10y ago
Okay, so you're creating many approximate representations of opaque and (mostly) rigid real world objects, and don't care about surface topology, rigging or UV layout. Using raw scan data works for that highly specific workflow, but let me assure you that for the overwhelming majority of the various 3D industries this is not the case. > Making those models is much more efficient with structured light or photogrammetry systems Only if you don't care about topology, representing unscannable things, polygon efficiency, UV layout, rigging, etc etc etc. For animation it's nowhere near competitive at present - you basically have to resculpt or retopo everything for anything but static matte background props. Maybe long-run pure scanning workflows will become more competitive, but that's not what my comment was about.
- AndrewKemendo 10y ago
  and don't care about surface topology, rigging or UV layout Not true. In fact those are important aspects - especially UV layout as texture baking correctly across dynamic finishes with the same underlying polygons is critical for accurate rendering. majority of the various 3D industries Like which? Aside from production level CAD/CAM we cover most other use cases as they are almost strictly rendering/modeling. Only if you don't care about topology, representing unscannable things, polygon efficiency, UV layout, rigging Again, not true. Especially polygon efficiency - our model requires polygon optimization so that our models can be utilized by low-bandwidth areas. It has been a massive challenge but one we cracked big nuts on. "Unscannable things" is an issue, but again, there are solutions including destructive scanning and X-Ray/MRI which give us insight.