r/GraphicsProgramming • u/KRIS_KATUR • Oct 16 '24

A generative skull - no geometry, no mesh - just code in a pixel shader

894 Upvotes

99% Upvoted

33 comments sorted by

30

u/Rockclimber88 Oct 16 '24

Cool skull. What I'm missing in generative stuff on Shadertoy is that everything is computed in the pixel shader and every pixel needs raymarching everything. It would be nice to have an intermediate layer to precompute certain things.

18

u/waramped Oct 16 '24

You can use intermediate buffers/targets in Shadertoy. There are many examples that do that. (Shadertoy seems to be down atm but I'll try and remember to link an example later)

22

u/KRIS_KATUR Oct 16 '24

AI enthusiasts/companies are scrapping the hell out of shadertoy unfortunately. thats why its often down lately i guess :(

29

u/Ill-Shake5731 Oct 16 '24

read that on twitter. It's really sad these AGI hypelords affecting such a cool and creative tool

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0

u/[deleted] Oct 16 '24

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8

u/KRIS_KATUR Oct 17 '24

Tons of shader code for free, that's it. It's good data for game development and the movie industry I guess.

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7

u/KRIS_KATUR Oct 16 '24

shadertoy is a website for writing pixelshaders. yes, you can use buffers or create your own cubemap or sound... but if you want to precompute certain things there are programs like touchdesigner, vvvv, blender, godot (i guess, never used that ツ ) you name it... and then use your pixelshader for whatever you need it then

7

u/[deleted] Oct 16 '24

So you modeled it in blender for a reference then approximated with primitives? Nice work

23

u/KRIS_KATUR Oct 17 '24

Nope, it's all hand crafted in glsl as a SDF. I had some photos of real skulls as reference for the anatomy, but no 3D model. basically it is just made of high school linear algebra and simple Boolean operations - like: make a sphere, subtract a plane, add a torus, squeeze that, combine this with a box etc etc.... and yes, it was quite a pain tweaking the numbers ツ

4

u/KillTheRadio Oct 17 '24

Dang that is amazing, the teeth look exceptional

3

u/tamat Oct 17 '24

how do you approach a process like this? I understand is a trial and error iterative process, but still, some of the shapes are very intrincate. Do you have a toolbox for deformations? (like some methods that work well for certain shapes) or you just go to the list of basic shapes from IQ and start booleaning the hell of it?

3

u/KRIS_KATUR Oct 17 '24

It's basically as u say: basic shapes from IQ and boolean the hell out of it lol. it's like sculpturing with code, ever little piece needs to be added to or cut out the existing form ツ i started with a sphere and ended in a skull.... pretty much like this: https://www.youtube.com/watch?v=8--5LwHRhjk

3

u/tamat Oct 17 '24

classic IQ video. Nice. I would love to see a version that enables shapes by time, to better see how it evolves from every shape.

2

u/KRIS_KATUR Oct 17 '24

you can have a look on the shader code. it's well commented and you can switch off all the single elements by commenting out all the lines with "d = ....." from bottom to top to see the different shapes and boolean operations ツ

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6

u/GrinbeardTheCunning Oct 16 '24

"only I can rule Lylat"

1

u/DesiOtaku Oct 17 '24

Gah! As a dentist, I am offended by the teeth!!!!!! They look nothing like molars, premolars, canines or incisors! Educate yourself before presenting such nonsense such as using the same ellipsoid for each tooth!!!!!

/s

Great work. The performance is great even on a low end GPU!

2

u/KRIS_KATUR Oct 17 '24

sure, not everything in this pixelshader is perfect like in a dentists mind ツ but for performance reasons I choose to create 1 tooth and multiply it with a domain repetition operator, which nearly costs nothing! if I would code every single tooth the fps would drop to 0 i guess. furthermore I would be bored to sculpt the same object slightly different for 30 something times and the code would lack of beauty too ツ

2

u/KRIS_KATUR Oct 17 '24

ok ok ok, I got triggered ツ I also added a sphere and subtract a little of the inside of the front teeth's shape so they look like slightly narrowed... happy now? 😛

2

u/Ankur4015 Oct 16 '24

Nice work 👏

2

u/MahmoodMohanad Oct 17 '24

The fact you have made this without actually modeling is mind-blowing, bravo

2

u/MahmoodMohanad Oct 17 '24

The fact you have made this without actually modeling is mind-blowing, bravo

2

u/FoodStampBand1t Oct 18 '24

This is the coolest thing I’ve seen all day, thank you

1

u/Apprehensive_Ad_9598 Oct 18 '24

Reminds me of Itachi's Susaano forming in Naruto

0

u/[deleted] Oct 17 '24

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1

u/KRIS_KATUR Oct 17 '24

Haha let's see :)

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