Fake stone export and 3D Scanning

Started by dorianvan, October 18, 2019, 06:56:10 pm

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dorianvan

Firstly, can TG export an object of a fake stone correctly? I'm having difficulty doing this.
Second, can Terragen do what amounts to a 3D scan around a piece of terrain or object? Like what Quixel does with their photography work/scans (www.quixel.com). Maybe I'm wrong, but I think Terragen can only capture an object straight at whatever camera trajectory you have and not a combination of angles, like if you animated the camera rotating around the desired object/terrain, and created a single mesh object.
-Dorian

Dune

Fake stones can't be exported. Imported objects can, but probably need reassigning textures. Internal objects (like cube) can't.
Have a look at this: export as vedisp map

I think it would indeed be possible to render an animation from a cam going around a (fake stone) terrain, and use those images in a photogrammical (photogrammatical) way in specialized software. Maybe lights need to be very soft non-shadowed.

What's the idea behind your question, I guess having to do with the project we're working on?

dorianvan

Strange that you can export terrain/imported objects but not fake stones/cubes.
Do you know if vector displacement maps export fake stones?
Great idea about capturing image and taking to another program for creating 3d model. It would be great though if TG could do that and cut out the middle man.
-Dorian

Dune

Vdisp export does that indeed. Did you see the tutorial by digitalguru?

Oshyan

You can export Fake Stones using Vector Displacement workflows or Heightfield Export, though of course with heightfield you lose overhanging elements. Fake Stones are just a displacement shader, they're not actual separate geometry. Vector Displacement workflow is probably your best bet to retain as much info and detail as possible.

- Oshyan

digitalguru

Quote from: dorianvan on October 18, 2019, 06:56:10 pmFirstly, can TG export an object of a fake stone correctly? I'm having difficulty doing this.

Dorianvan can correct me if I'm wrong, but I'm assuming he's talking about exporting a Rock object from Terragen?

If that's so, it is possible in a way. You could point an orthographic camera underneath a Rock object in the default scene (with flat terrain underneath) raise the rock so it's not in contact with the ground, and do a micro export of that. Make sure the camera is just above the flat terrain (and there is nothing "behind" the rock) and you have a rock object. Attached a simple example.

If you're talking about the fake stones shader - it's just that - a displacement shader and the rocks are obviously not discrete objects, but you can either micro export the patch of terrain that has the rocks you want, or as Dune mentioned make a vector displacement of the same area. The advantage of the vector displacement is that you can take it into a sculpting program like Mudbox and finesse the rocks by hand.

I do that with any "hero" fake stones that I use as you can fix some of the artifacts the fake stones shader sometimes produces. You can then export that back to TG as geometry or as vector displacement again - you just need to lower the formation a bit in the scene to hide the patch of ground that is attached to the fake stones.

The Photogrammetry idea is interesting, but I think it would be difficult to get right. Photogrammetry software looks for details in the image that it can lock onto and match to calculate a 3d mesh, and shading a terrain in TG might not give it enough unique detail to lock on to.

In any event, you can always make a micro export of anything that renders as a polygon in TG. That includes imported objects and even populations. I guess you might be wanting to capture texture detail as well (as photogrammetry can). If it's just terrain you are capturing you can get away with doing an ortho top-down render to get a color map and that works well in a lot of cases.

Or as an idea, you could set up a bunch of cameras around your section of terrain in TG and render color maps from that, then export the same cameras to a 3d app and do some camera projected textures to recreate your texture detail. I haven't done much texture projection, but I imagine that's possible - probably a lot of work though and there should be easier alternative solutions.

dorianvan

Quote from: Dune on October 19, 2019, 11:39:36 amDid you see the tutorial by digitalguru?
Going to watch now. Thanks.

@ Oshyan and Digitalguru, thanks. I will look into vector displacement for doing this.
-Dorian

Dune

@digitalguru ; that export works really nice. Never knew this was possible, but even a cube with fake stones can be exported an object. Very handy to know.

WAS

Quote from: Dune on October 21, 2019, 02:43:04 am@digitalguru ; that export works really nice. Never knew this was possible, but even a cube with fake stones can be exported an object. Very handy to know.
What about fake stones driving a default shaders opacity and exported? Haven't tried but in theory you'd get a top down of stones cut off on the bottom.
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