Volumetric Decal tests

Since UE 4.9 can do volumetric decals (a.k.a, raymarched procedural distance fields), I though I’d render some 3D fractals to test the feature.

The Volumetric Decals feature is only experimental, and so the objects defined this way do not cast shadows or occlusion. Also, when animated, they don’t play nicely with the Temporal Anti Aliasing. But they are good fun.

WOAH! What?! How. How do you generate those. I don’t care how broken that is I want to do it to!

Unbelievable! Did you write the fractal function yourself?

The answer is undoubtedly. There’s one specific Inigo I can think of that would do this sort of thing. What an awesome world this is if there’s more than one!


I added a more complex distance field to see what it would take in the material editor to create a more realistic/useful object. Even after encapsulating the SDF primitives and operators in MaterialFuncions, and taking a modular approach to the modeling (reusing the leg distance field 6 times), still the complexity (ie, amount of nodes) grows too much quickly… I’m not sure a graph-node style UI is the right approach for this task. But other than that, this new Volume Decal feature is pretty awesome!

Yepp, I suspect that’s THE Inigo! :wink:

Sorry to be the token noob here but, what are the use cases for volumetric decals?


One solid, already in use, case is for masking out 3d geometry.

DFs have the ability to quickly and efficiently represent artistic and organic forms, precision parts, high-order functions, and fractals.

DFs also have important processing operations, including rendering, sculpting, level-of-detail management, surface offsetting, collision detection, Boolean operations, blending and filleting, creating offset surfaces, and morphing between shapes.

If you want to play around with them I suggest something like

uho, we have shadertoy bugs in UE4!! (pun intended)

Looks awesome, thanks for posting, Inigo!

And for those curious… Inigo already gave a bunch of great technical feedback to the programmer who made the voldecals and that feedback has already been implemented. Woot!

This is fantastic, inspiring and very relevant to my interests! Thanks for posting :slight_smile:

You could test Custom node so you can just hand write shader code snippet directly.

Very cool! It’s nice to see someone using the feature!

I can’t imagine they’ll be hugely useful in a title anytime soon since their still so expensive, but WTH

Can someone please explain the process to integrate raymarching.
Where would I put the code for a signed distance function?

Can yo share how you did this?

Wow, this is really cool =D I’m impressed!

O yesh, would love to see how to implement this, any screenshoot or tutorial I can follow?