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And the suddenly widespread availability rather than a select few building. There's something to say for either approach.

by lucb1e 6y ago

rasz 6y ago
Google doesnt use AI/ML for automagic photogrammetry, as a result they are really bad at things like balconies looking more like a glitch than a building feature. They also dont feed 3d models back into their maps. My building stopped existing on Google 2D map sometime 10 years ago despite having fairly accurate 3d model.
- lucb1e 6y ago
  If you're into that sort of thing, OpenStreetMap supports 3D mapping as well. I haven't looked into it but while from my understanding it's fairly basic, at least you're sure that your data will be around in ten years and openly available for people to use and display.
- bitL 6y ago
  Balconies are simply about what the threshold for shape simplification is. It's just way too much data to represent a whole city and download it over Internet so somebody decided that buildings should look pixel-perfect from half a mile away, but getting closer one could see funny edges etc. so common for edge-collapsing 3D shape simplifications.
  - rasz 6y ago
    The problem is its not edge collapsing, its somewhere half in the middle producing triangle shaped protrusions with bad perspective texture on top. In this particular use case photogrammetry algorithm should have some hardcoded common sense to detect boxy building and try to maintain flat surfaces and straight lines. Instead it looks like Google picked one of the open source SLAM implementations and deployed it at scale without fine tuning :( Look at 41 central park west train wreck. You have >20 good photos to work with, but the end result doesnt even maintain straight windows. Balconies look like Lara Croft breast from first Tomb Raider, not to mention they are all different geometry despite high quality source material showing them being all the same shape. The best data saving option would probably be no additional geometry at all, just a texture.

And the suddenly widespread availability rather than a select few building. There's something to say for either approach.

by lucb1e 6y ago

And the suddenly widespread availability rather than a select few building. There's something to say for either approach.

rasz 6y ago

Google doesnt use AI/ML for automagic photogrammetry, as a result they are really bad at things like balconies looking more like a glitch than a building feature. They also dont feed 3d models back into their maps. My building stopped existing on Google 2D map sometime 10 years ago despite having fairly accurate 3d model.

lucb1e 6y ago
If you're into that sort of thing, OpenStreetMap supports 3D mapping as well. I haven't looked into it but while from my understanding it's fairly basic, at least you're sure that your data will be around in ten years and openly available for people to use and display.
bitL 6y ago
Balconies are simply about what the threshold for shape simplification is. It's just way too much data to represent a whole city and download it over Internet so somebody decided that buildings should look pixel-perfect from half a mile away, but getting closer one could see funny edges etc. so common for edge-collapsing 3D shape simplifications.
- rasz 6y ago
  The problem is its not edge collapsing, its somewhere half in the middle producing triangle shaped protrusions with bad perspective texture on top. In this particular use case photogrammetry algorithm should have some hardcoded common sense to detect boxy building and try to maintain flat surfaces and straight lines. Instead it looks like Google picked one of the open source SLAM implementations and deployed it at scale without fine tuning :( Look at 41 central park west train wreck. You have >20 good photos to work with, but the end result doesnt even maintain straight windows. Balconies look like Lara Croft breast from first Tomb Raider, not to mention they are all different geometry despite high quality source material showing them being all the same shape. The best data saving option would probably be no additional geometry at all, just a texture.