What I’ve been doing is turning the terrain into a mesh, importing that into Blender, then punching holes in the terrain and connecting them. That’s incredibly, incredibly time intensive though (I think building the vertex links at the cave entrance from the terrain will take longer than any other part of my project), so I’m curious if there are other relatively simple ways known to create caves in Unity. Can anyone recommend anything?
What about covering gap between the hole in the terrain and the cave with some fake rock action?
I imagine that would be useful.
I was more hoping for just some better way to make the caves themselves. Theoretically some automated (or at least simplified) process compared to creating it in Blender.
I’d love to have a tool that used procedural generation somehow, but I don’t know of any myself.
I was thinking in blender using the ant landscape addon, maybe sculpting and then using the decimate modifier to reduce the poly count. I can’t imagine that to be too tedious, it sounds like you pulling vertices.
The following video looks like a good idea too.
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That looks quite impressive. Thanks.
I spent a morning and made about 20 prefabs just putting rocks together and then using SimpleLOD to merge the meshes and cut down the polycount. I was thinking about selling them on the asset store or just giving them away. It is nice to have simple ones that you can just throw down and decorate. Going back and forth to blender is such a hassle and you still have to deal with the entrance either way.
There are number of voxel engines on the asset store and on the web. Very good, smooth type, not the MC type.
You know, voxels don’t automatically mean fully destructible terrain. Sure, they can and make it extremely easy, but voxel terrain is also useful in making complicated terrain features such as caves or overhangs.
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I’m using TerrainComposer to procedurally generate terrain. The project I’m concerned about at the moment is using a given terrain so I can mess with it, but a future project will involve procedurally generated terrains at runtime.
I suppose it’s a concern in either case, but basically I’m unsure how well voxel terrains work in conjunction with normal systems.
What kind of “normal systems” have you in mind? I can provide more directed response if you say.
But here’s what I can say now: most voxel terrain systems generate appropriate colliders so physics aren’t a problem. Another thing is that you can easily fast iterate on terrain, even with complex shape (overhangs and caves). Finally, the fact that voxels have capability of realtime modification, you won’t have to write much code if you end up kinda wanting it in your game or players request it much. With mesh- and (to a lesser degree, but still) heightmap-based terrain, you’d have most likely reengineer whole system.
I’m not good with art stuff, but if you want to use blender to model caves, maybe you could use sculpting to make the cave system openings and then make a large block and subtract the cave internals from that block.
I don’t know if I’ve got any correct terms there. You know when people poor molten aluminum down an ant hill and pull out a solid structure of what it looked like? Model that and subtract that from a large cube / whatever base shape in blender and you’ll have a nice cave system.
I just mean a typical Unity terrain. As far as I know they aren’t voxels so I don’t know how well the two would interact with one another.
I tried using a system similar to that video posted above to build the cave itself and it worked pretty well. However, I tried to do something like what you suggested with the cave entrances (overlay the entrance and my terrain exported from Unity, then cut them both on the overlapping parts) but I wasn’t able to get it to work. Blender’s main tool for that is rather cumbersome. Thanks for the suggestion, though. I intend to keep working on it.
Do you mean the sculpting tool or subtracting geometry? I think I did something like this to make a hollow sphere once. I don’t recall that part being difficult so I’m guessing that your issue is a combination of blender’s interesting camera and sculpting a cave system.
But again, I have negative art skills and opinions, so my advice will probably be the kind to go against on this subject.
They don’t. Voxel terrain would just replace regular unity terrain. No reason to use both.
A voxel system could be used for building on top of a static terrain. But I’d probably prefer voxel terrain when ever possible. I wonder how long before that’s a standard engine feature - destructible everything on the fly.
I only did it once, but the way I did it is make a cylinder or whatever shape you want (that metaballs trick is nice) then hit noise and randomize button a few times to make it not smooth, and for the spiky stuff from the video I selected random top and bottom faces (I think theres a button for that too, then just deselect the selected wall faces) and dragged them inward, and extruded a bit and got the same result. Then just added some details like crystal stones and stuff. And I connected them to the world the way Skyrim did. If I wanted it all in the same scene I’d use the fake rock action Bridin suggested. 
I’d do it in blender. Seems like a lotta work to do it in unity