Ask HN: Best Graphics libraries to build CAD solutions?

If you are being pragmatic about things, a game engine is probably the best. For 3D, give Godot a try. Otherwise there are plenty of other commercial solutions (Unity, Unreal, there are quite a few). 2D engines are more common than 3D engines, so simply select one that is most compatible with your preferred tech stack. Game engines will require more upfront work for the GUI part of CAD software, but it will make the actual CAD a lot easier as a large amount of constraints and collision physics already come built in. Modern game engines also come with importers for common CAD file formats, so that will make your life a lot easier too. The modern Unity-style game engine with everything and the kitchen sink included is somewhat of a recent phenomenon. Traditionally game engines are small poorly documented libraries and therefore less than helpful unless you were truly desperate. Also, the CAD field moves slowly when it comes to adoption of new technology and most of the incumbents are still using core in-house technology from decades ago. My above assessment is based on the current state of the art for both fields.

Some helpful links:

http://www.publicworksgroup.com/blog/2012/02/will-gaming-eng...

https://www.unrealengine.com/en-US/spotlights/meshmatic-opti...

https://www.researchgate.net/figure/Unity3D-Game-Engine-and-...

If you're building for the web, konva.js apparently can do that. I recently spent a few days reasarching for libraries to implement simple CAD functionality (similar to what you would use for a gerber file viewer), and finally decided to use that library.

The other options I considered were: - pixi.js (very popular and active, very high performance, too low level for my needs) - fabric.js (also very popular, similar to konva but does not support layers functionality)

Konva seems to be very actively maintained, and has been around for several years. Users in forums seem mostly happy with it. Very simple to use too (I'm just starting with it, so not much experience).

https://konvajs.org/docs/sandbox/index.html

If you're targeting a browser based solution. Three JS and Babylon.js gives you the building blocks.

If you're looking more of a Constructive Solid Geometry based web solution jscad/CSG.js.

If you want something more turnkey with a BREP kernel look at what the folks at https://www.autodrop3d.com/parametric-cad.html and https://buerli.io/ are building. Super interesting.

Not affiliated with the above companies, I just do dev on related software.

Autodesk Fusion 360 uses Qt gui library. Some screenshots of its UI : https://www.google.com/search?q=%22autodesk+fusion+360%22+ui...

Here are some more CAD apps using Qt: https://en.wikipedia.org/wiki/Category:Engineering_software_...

(Although Fusion 360 was launched June 2013, nobody edited the wiki page to include it yet.)

If open source suits you fine then I would recommend Blender. See [1] and [2] as examples of blender plugins for open foam based simulations.

With Blender you get advantages of open source, game engines and a fairly extensible 3d toolkit.

[1] https://github.com/dmsurti/reynolds-blender

[2] https://github.com/dmsurti/reynolds

Disclaimer. I am the author of [1] and [2].

I think your question is very-very related to your development language.

- 1) C++ : I think many, if not most 3D graphic libraries are based on C++ language. I am no specialist here.google it.

- 2) java : I use java3D but I believe there are now other more active 3D apis .Like JMonkey.

- 3) javascript/typeScipt : If you use the web as your target, I think the best-and-easiest 3D API is clearly BabylonJs. I use it and I think it is super easy to begin wih.

Thierry, https://free-visit.net

Since you asked about Java 3D, I assume you want to render 3D in your app.

I’ve built a couple of moderately advanced CAD/CAM/CAE apps with WPF + Direct3D 11. Both me and my clients were happy with the software.

You don’t want C++ for 2D GUI parts, or other higher-level pieces like disk I/O or networking. It’s too low-level, and too unsafe which inevitably gonna cause issues once your code grows complex enough. If you only want to support Win10, UWP might be even better because easier to integrate with Direct3D, for WPF you’ll need to write a page of C++ code to make sense of DXGI surface sharing (WPF renders with DirectX9 not D3D11, but it’s possible to pass frames in VRAM by sharing a texture).

On Windows, you want Direct3D for the GPU API. If you have a good PC with a recent nVidia card all of them gonna work great. However, as your install base grows, you’ll inevitably have to deal with Intel and AMD GPUs (Intel only supports VK since Skylake), GPUs older than a few years, outdated GPU drivers, and other shenanigans. Direct3D is way more reliable than GL or VK in these cases, because supported by MS (GL and VK are only supported by GPU vendors), better integrated into Windows (major parts of D3D are in dxgkrnl.sys kernel mode driver), and used a lot by the OS itself (since Vista, desktop compositor uses D3D to render desktop; in Win10, all UWP apps like calculator render with D3D 11).

You do want C++ in the backend. Not just because D3D (that alone is solvable with SharpDX and others), because too many C++ libraries useful for CAD were written over the course of decades. The 3 most useful for me were DirectXMath, Eigen, and Geometric Tools. Fortunately, interop between C++ and C# in the same process is both simple and efficient. On Windows I usually use COM interfaces created by C functions exported from a native DLL.

Game engines are huge, and designed for different use cases. They are trying to render stuff at refresh rate of the display; you don’t want that in a CAD app, your only want to render frames when things change. They assume most things are immutable once loaded from disk and rely on offline pre-processing for a lot of things, while CAD apps need to import whatever, and many things are user-editable. Game engines often strive for photorealistic rendering. You probably don’t need deferred shading or volumetric lightning in your CAD app, let alone water, vegetation, day/night cycle or character animation. All these features complicate a lot of things in game engines.

If you want to be able to port to non-Windows, look for a GPU abstraction library as opposed to a game engine. For example, I have positive experience (unrelated to CAD) with this library http://diligentgraphics.com/diligent-engine/ It has “engine” in the name but I don’t think that’s an engine, it’s a GPU abstraction library which was exactly what I wanted.

qt

Because someone said game engines, I recommend Bevy engine (Rust, with full web support). Includes good UI solution.