Henry "volumetric colorizers"

Hi everyone !

I was wondering if the volumetric colorizers used in Henry are possible without altering UE code (so only in the material editor with some custom nodes) ?

Thanks !

Well looks like they have changed the engine sources I would say, but you can hack some of the parts with particles or materials in the materials editor as some kind of small fog systems.

You don’t need any engine code to do what they are doing.

The effect is basically what we used to call a “Fog Sphere” in UE4. There are some cool changes that are easy to apply. Its based on the same same way I did things like glows from fires in the kryll level of gears 1 so the player could clearly tell when they were in the light safe zones.

These are all still in engine under Content\EngineVolumetrics\

But they are a bit dated and could use improvements.

One cool part about what they are doing is using an analytical integration of “quadratic falloff”. The words inverse square falloff are a bit of a misnomer IMO as it is used. In my previous testing, you can get something very similar by just using a Power on the fresnel of a sphere. You can use the function “Ray Traced Sphere” in UE4 to get the starting position of the outside of the sphere.

Another good things they are doing is to render using the Inside faces instead of the outside faces. Then you disable depth test on the material, and do “Depth Fade” manually. We have done that in the past for other effects as well, any time you want to control opaque sorting.

The robo recall guys are actually using the same technique from the oculus link for nicer glows now as well, and its all just regular materials. Does not even require the custom node.

Thanks Ryan …
… But you talk a bit too technical for me :slight_smile:

Here what I have now :

When I am outside of the sphere, it looks ok :

But when I am inside the sphere, it’s not really working. (images on the left are what I have, on the right are what I want)

I really don’t know if it’s possible (maybe with the “Ray Traced Sphere” function that I totally don’t understand).

If you need some kind of fog volume, you can check the Kite demo have a sphere function that you can see fog in and outside, give a effect more or less like that, but not sure at all if is that what you need.
You can copy and just change the colors.

Anyway with the manual way you will have leaks cross walls, their demo looks like have it coded.

Hey, for some reason I glanced over your user name.

Here are the basic steps to make it work:

Import a Sphere with inverted faces.
Set the material to “Disable Depth Test” in the shader.

Then you can go inside of the sphere, now just have to make it sort. Will post back in a bit an example using the sphere function. a bit rushed prepping for stream later at 2.

edit good recommendation for kite sphere, I forgot about that fog volume. I set that one up but forgot about it since I have made so many similar ones.

c5b6e7e92296cbfa74306b34012be9da2eeb8862.jpeg

The function on the bottom shouldn’t be necessary, but for some reason the “0-1 sphere density” on raytraced sphere output was broken. That function needs some love as the outputs were inconsistent (ray exit distance, but no ray entry distance? ). In fact with a better sphere function half of this graph would go away.

6c4bd1ed1c48d84b411304a67c2c6bbd18f4b1bb.jpeg

I am doing a super simplified version of the ‘bright core’ in the center here, by basically using a fresnel type falloff to pretend the sphere is thicker facing the viewer. It holds up as you go through but isn’t as accurate as IQ’s true integration.

pretty sure the kite one was just exponential density from linear distance, which wouldn’t have a bright core.

Here is a simple version without a bright core, that uses exponential density and you can go inside. much easier to setup:

9685c7c892e09f286070fd862d9bb7d066b23a3d.jpeg

Also I have a new true inverse square falloff integration version that works with spheres, cones or any shape that is much more accurate and the core sorts properly. The above versions the core will appear to sort a bit too far away once you go inside of it. Look for it in the 4.15 release notes.

Thank you both !

Ryan, I tried your shader but for some reasons, it don’t work as expected.
I finally end up with this, I don’t know if it’s a “correct” way do to it, but it does what I want :slight_smile:

Looks pretty good! is that color fringe coming just from post? you could also try using something like the 0-1 thickness (with power) to blend between two separate colors. Inigo’s article mentioned doing that as well.

*is that color fringe coming just from post?
I’m not sure what you call “color fringe” but it certainly due to post process, as I used exactly the material I posted.

*One little last thing that bover me a little : Is it possible to make the sphere not visible to SSR ?
Left images are without the sphere / Rights are with the sphere
Up images are with SSR / bottoms are without
*
http://tof.canardpc.com/preview2/9068361c-0849-4c22-8115-720e5b2f7b99.jpg

*But it’s a detail, I’m already really happy with it :slight_smile:

Ha, this is cool! Would you mind sharing a slightly bigger pic of your graph? :slight_smile:

Cheers!

Yep, sorry.

Thank you so much man! I am just trying different approaches right now as well and I am not yet satisfied completely :smiley: I like Ryans suggestion, but it seems to change the falloff depending on the sphere size so I wanted to give yours a shot as well^^

Thanks again and cheers! :slight_smile: