Suggestion: Simple Three.js robust Booleans example about manifold

[bhouston]

CSG usually refers to a rendering trick that makes Boolean operations look right, but doesn't actually compute them.

I was refering to actually intersecting the meshes and calculating the mesh result live in the browser. Similar to what we did with Clara.io back in 2013 here - and this isn't a rendering trick, try it in the editor, it is live Boolean mesh result (and completely unreliable on complex meshes):

https://clara.io/view/86e0579a-4dc8-4145-81a8-6ad9f765b30b

[bhouston]

Ah, I understand. CSG often refers to building from primitive shapes using Boolean operations. I guess I've seen CSG misused so many times (e.g. https://evanw.github.io/csg.js ) then I've conflated it with Boolean operations and continued the confusion.

I am interested in Boolean operations only. I've edited the title.

[elalish]

@manthrax Here here! And agreed that CSG and so many other terms in the CAD space tend to be overloaded and confusing. In any case, it sounds like this library is well-aligned with your desires. Of course it isn't JS, but there are a variety of ways we could look at making it web-accessible (WASM, REST API, ...).

[elalish]

CSG usually refers to a rendering trick that makes Boolean operations look right, but doesn't actually compute them. For graphics that is often much simpler. This library is for actually intersecting meshes, so more in the realm of a design tool than a rendering tool.

[manthrax]

imo Constructive solid geometry/CSG is a fine term for geometric boolean operations or for the visual only version. They are not mutually exclusive.
There are already a number of visual/stencil buffer tricks available for rendering only. i.e. Goldfeather and ZBuffer. but they rely on having a well structured graph of operations that isn't always trivial to construct/implement.

Here's a demo of a CSG lib I maintain that is based on evanw's CSG but extended to preserve uvs/normals/colors and materials:
https://manthrax.github.io/THREE-CSGMesh/demos/CSGShinyDemo.html
(you can hit W to see wireframe.. and show that it's actual geometry and not a stencil effect.)

What would be lovely to find is something that can do this but faster! and for more complex objects! :)

Right now it's N squared with the number of polygons involved since there is no search acceleration/culling strategy.

Having something more optimal could unlock a whole host of runtime web procedural generation tools!

[pca006132]

@elalish is this considered finished? Or do we want to extend the three.js example?

[elalish]

I definitely want more, but agreed that we now have a simple three.js booleans example: https://elalish.github.io/manifold/bindings/wasm/examples/index.html