Panda3D VS Bullet

Panda3D (MIT/C++) https://github.com/panda3d/panda3d

For open source 3d engines that use Python check out Panda3D or Ursina. They're both a blast to use and let you write your codd how you want.

[0] https://www.panda3d.org/

[1] https://www.ursinaengine.org/

Panda3D: Let's you make games with c++ and python. I don't think there is an "editor" or anything like that with this engine, but it does look like there have been some decent games made with it. Could be good for smaller games. Modified BSD License.

I know a lot of people recommend Godot because it's super good but if you want a more code oriented and batteries included engine I recommend Panda3D [0] it's open source, super mature (it's actually one of the oldest continously developed game engines), and can be used form Python and C++. Not sure why it's not more popular it's flexiable and super fun to use.

[0] https://www.panda3d.org/

Some of the game engines we have now have photogrammetry technology built-in, meaning that developers can easily integrate it into their games. This allows for even more detailed and realistic environments to be created in 3D games. The most prominent being Unreal, Unity, and Lumberyard -- including new and beginner-friendly ones like Panda3D and Yahaha. All of these game engines have photogrammetry at their core to help developers create realistic 3D models and textures quickly and efficiently.

Make sure to provide your junior developers or any new members with the resources and tools they need to succeed. This could include coding books (The Self-Taught Programmer was my favorite before), online tutorials, or access to development tools and software. There are game engines available that can be a training ground for new devs, some of the game engines I’ve tried are Panda3D, GameMaker and Godot. I’ve also tried newer engines like Yahaha, but this one is pretty easy compared to other engines so there’s really not much of a challenge. The point is, no matter what resources and tools you provide, make sure they are tailored to the skill level of your junior developers.

...and there are some samples in the source https://github.com/panda3d/panda3d/tree/master/samples

It's not my project, but https://www.panda3d.org/ is to my knowledge the next best step after Unity and Unreal game engines. Unlike those, panda is open source and available for C++ and Python.

For typical game physics engines... not that much. Math libraries like Eigen or Blaze use lots of template metaprogramming techniques under the hood that can help when you're doing large batched matrix multiplications (since it can remove temporary allocations at compile-time and can also fuse operations efficiently, as well as applying various SIMD optimizations), but it doesn't really help when you need lots of small operations (with mat3 / mat4 / vec3 / quat / etc.). Typical game physics engines tend to use iterative algorithms for their solvers (Gauss-Seidel, PBD, etc...) instead of batched "matrix"-oriented ones, so you'll get less benefits out of Eigen / Blaze compared to what you typically see in deep learning / scientific computing workloads.

The codebases I've seen in many game physics engines seem to all roll their own math libraries for these stuff, or even just use SIMD (SSE / AVX) intrinsics directly. Examples: PhysX (https://github.com/NVIDIA-Omniverse/PhysX), Box2D (https://github.com/erincatto/box2d), Bullet (https://github.com/bulletphysics/bullet3)...

I suspect most C++ physics libraries like Box2D (https://github.com/erincatto/box2d) or Bullet3 (https://github.com/bulletphysics/bullet3) could really benefit a lot from SIMD.

No, they replaced Bullet with Jolt. That is considerably more than "some adjustment", regardless of what you think of the result.

Vulkan graphics via Intel GVK, and physics via Bullet

The first two have a bunch of great examples, and I’m tying them together by refactoring some of the THREE examples to fit the ECS paradigm defined in AFrame. then upping the ante by adding physics using AMMO, which is more challenging since it’s only a partial implementation of Bullet, and already poorly documented (yet popular) physics engine.

Plus, SM uses a system called bullet physics, I imagine this would be rather complex to rework into a modern engine such as Unreal or Unity (after all, the majority of performance issues come from the physics engine rather than the graphics engine)

The physics in HDT-SMP are actually being calculated outside of Skyrim's engine with Bullet, an open-source physics engine. So this isn't some limitation of Skyrim's engine.