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Comment by ubercore | Hacker News Reader

I'm skeptical too, but I could envision a path where this gets a lot of the work done at a tooling level. All these products will have CAD models behind them already, AutoCad and SolidWorks, et al, could introduce tooling to pump out the assets necessary for this at not-terrible levels of effort, couldn't they?

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One of the advisors to Magic Leap is currently the CEO of Onshape (and was also the creator of SolidWorks). There will surely be an Onshape app for Magic Leap at some point.

Back in the 90's when I was doing 3D on the web, we looked at this and the results weren't compelling. The models used for CAD/CAM aren't the same sort of thing you would want a GPU to try and render in a 3D scene. Just as one trivial example, none of them had normals so you'd need to do a lot of model cleanup simply to get them to render as a solid object.

Can't you just calculate the surface normals? What am I missing?

You had to be able to orient the normals correctly. For a hull this might be easy enough but for many objects it was a challenge.

Gouraud shading like it's 1989? :)

CAD data is getting used more often in 3d graphics (although there's still some cleanup). It's used commonly for product shots and starting to be used for games. The most recent GDC had a McLaren pulled from CAD data running real time in Unreal Engine[1]. I honestly don't think much cleanup was done because of the timeline for projects like these (I thought I heard 6 weeks start to finish focusing on custom engine development for interaction and shading).

In my experience, the problem is more in how the model is organized; having ever screw or washer as a separate piece of geometry causes problems (3d tools have trouble with very large geometry counts even if the poly count isn't high). CAD data also doesn't work very well with non-hard materials like upholstery; stitching is likely missing, as well as things that make cloth/leather look normal like pinching or gravity pushing on things.

[1] https://www.youtube.com/watch?v=0oZfvoG6qYQ

Sure, and there are already standards for exporting 3d geometry data.

The process isn't rocket science but the scale is.

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