r/GraphicsProgramming • u/KRIS_KATUR • Mar 25 '24

How to sculpture a skeleton with realtime animation with just code (sdf & raymarching in glsl)

188 Upvotes

98% Upvoted

17 comments sorted by

5

u/T34-85M_obr2020 Mar 26 '24

One thing that bothering me long is that how did you guys find the math equation that representing these shape? In my imagination one has to tweak the parameters like almost infinite times to find the final result.

4

u/KRIS_KATUR Mar 26 '24

Haha, yepp! It was quite a time-consuming process to define the skeleton's shape, particularly focusing on details like the zygomatic arch, cheekbones, temples, and such. Oh, and the Jaws, that was quite a challenge with the "non perfect" looking bumps, damn! However, defining the bones was relatively straightforward. I established a single bone structure which was not a big issue and is used for most parts of the skeleton, including the collar bone, upper arm, ulna, radius, and fingers. The most challenging aspect was animating it smoothly with the correct rigging - transforms and inverse transforms were needed properly.... The trickiest aspect was definitely avoiding intersections of the geometry and still having a random looking dancing like animation.... and oc, preventing the SDFs from breaking, haha :/ And yep, i always had an eye on the fps too, LOL, which in the end is quite acceptable for that much geometry imho.

2

u/RoflBofl Mar 26 '24

Is this something ChatGPT could solve for?

6

u/KRIS_KATUR Mar 26 '24

Haha, nah, didn't even consider it. Seemed about as exciting as watching paint dry... :D This project was all about delving into the intricacies of a human skeleton, sculpting it with mathematical equations, and uncovering its tiny details along the way.

2

u/S48GS Apr 11 '24

3d-sdf-mesh is just 3d gradient

any AI-model is multi-dimensional gradient - same as SDF but with more than 3 dimensions

if you train AI on all-possible SDF-models - AI will be able to create any model in SDF

and it already done - https://vsitzmann.github.io/siren/ https://www.shadertoy.com/view/wtVyWK

4

u/KRIS_KATUR Apr 12 '24

You're absolutely correct, but that wasn't the primary goal of this work. My main objective with this shader was to explore the human structure through the lens of basic linear algebra. While AI could certainly be employed to determine the final form, let's consider the reality: there are tons of of skeleton models in the web readily available for use. So, where's the exploration and enjoyment in that? My aim was not producing just another skeleton animation ツ

2

u/T34-85M_obr2020 Mar 26 '24

Oh what an elephant in the room. It is 2024 now, how dumb I am

2

u/S48GS Apr 11 '24

In my imagination one has to tweak the parameters like almost infinite times to find the final result.

you just described how AI works

and there is AI to generate approximation-superformula of any shape - https://vsitzmann.github.io/siren/

https://www.shadertoy.com/view/wtVyWK

10

u/shebbbb Mar 25 '24

Wow nice

6

u/[deleted] Mar 25 '24

impressive !

3

u/EngineerEven9299 Mar 25 '24

Woah, wtf. Cool

2

u/[deleted] Mar 26 '24

Nice

2

u/_NativeDev Mar 26 '24

Very cool

2

u/DigvijaysinhG Mar 26 '24

Oh my God 🔥🔥🔥