2020 Dev Update #02 - Squashy Skin System (Patreon)

I've been making some progress with the poseable rig that will serve a couple purposes - for me to create scenes and animations within the engine, and for the player to pose and play with her in-game.

I dev'd a feature that I think adds a lot to the realism of her body and makes the actual rig a bit easier to handle too - a squash & stretch spine IK system. The concept is that real spines don't really compress or squash much in real girls, but they can have the appearance of doing so based on the curvature of the spine and the amount of soft squishy flesh around it.

In game characters we generally don't have such a high fidelity spine to work with, and the method of skinning vertices to bones without any other factors involved, such as underlying fat, skin flexibility and elasticity can't match such a complex IRL system.

Instead I'm faking it with some trickery -

The diagrams and the actual result above is way exaggerated, but the idea is to try and emulate real skin and bones with a system that instead "fakes it" by unrealistically squashing the bones. The bones squashiness drives morph targets of folded skin and fat, which makes it so that as bone compression happens, the fat underneath causes the skin to fold and crease.

Quite an exaggerated clip, but shows what the actual skeleton looks like as we squash her:

https://twitter.com/NaughtySandbox/status/1218166587548676097?s=20 

The concept of this system is probably going to be used in multiple other places on her body, to try and recreate all the major areas where skin and flesh fold and displace based on what the body part is doing, since I think it adds a ton to the overall look!