Great comments and tutorials!
I’m a 3d artist and have been exploring the possibilities of using 3d as reference for 2d poses. I want to add a couple of tips and things!
Sketchup is very useful for environment references, and I assume it’s reasonably easy to learn. If you’re interested in going above and beyond, I highly recommend learning a proper 3d modeling program to help with art, especially because you can very easily populate a scene or location with characters!
Using 3ds Max I can pretty quickly construct an environment for reference. But going beyond that, I can also pose a pretty simple ‘CAT’ armature (known in 3d as a rig) straight into the scene, which can be totally customized, from various limbs, tails, wings, whatever, to proportions, and also can be modeled onto and expanded upon (for an example, you could 3d sculpt a head reference for your character and then attach it to the CAT rig, so you have a reference for complex face angles!)
The armature can also be posed incredibly easily. I know programs exist for stuff like this - Manga Studio, Design Doll - but posing characters in these programs is always an exercise in frustration and very fiddly imo. A simple 3d rig is impossibly easy to pose.
By creating an environment and dropping my character rig into it, I have an excellent point of reference when it comes to drawing the scene!
Not only that, but I can also view the scene from whatever angle I could ever want or need, including the character and their pose/position relative to the environment.
We can even quickly and easily expand this scene to include more characters!
Proper 3d modeling software is immensely powerful, and if you wanted to, you could model a complex environment that occurs regularly in your comic or illustration work (say, a castle interior, or an outdoor forest environment) and populate the scene with as many perspective-grounded characters as you need!