Volumetric Fog feedback thread

[II_ADN_II]

Hi, dont know if it was said before, but increasing fog distance crash the volumetric fog when the camera moves and the screen end up completely black. this doesnt happen in small scales. Shouldnt the fog be able to work as expected despite the scale? Is this a bug? Any solutions?

PD: is there any plan to make the light functions work with the volumetric fog?
PD2: It actually work with directional, not with point or other type, have to use the texCoord instead WorldPosition to map the function

[II_ADN_II]

Bump, any workaround or solution?

[II_ADN_II]

@II_ADN_II

Hi, dont know if it was said before, but increasing fog distance crash the volumetric fog when the camera moves and the screen end up completely black. this doesnt happen in small scales. Shouldnt the fog be able to work as expected despite the scale? Is this a bug? Any solutions?

PD: is there any plan to make the light functions work with the volumetric fog?
PD2: It actually work with directional, not with point or other type, have to use the texCoord instead WorldPosition to map the function

Bumping for help

[rosegoldslugs]

Even if that was supported, you wouldn’t really get much back. You’d be stretching the volume texture reeeaaallly far and would lose any/all definition from shadow casters. Only use case of volumetric draw distance of 100,000,000 that I can think of is a planetary-scale game, which UE4 doesn’t really support out of the box anyway so you’d likely be looking at a custom solution.

[II_ADN_II]

@rosegoldslugs

Even if that was supported, you wouldn’t really get much back. You’d be stretching the volume texture reeeaaallly far and would lose any/all definition from shadow casters. Only use case of volumetric draw distance of 100,000,000 that I can think of is a planetary-scale game, which UE4 doesn’t really support out of the box anyway so you’d likely be looking at a custom solution.

The problem is that you can use the volumetric fog to simulate sun rays trough the clouds. It works perfectly but only in really small scales. There isnt a reason why this shoudnt work on a real scale since the resolution of the shadows and the volumetric fog still the same. Also the draw distance of 100,000,000 is just as an example in an empty scene, unfortunately it breaks much earlier in a standard game scene with lots of assets.

[anonymous_user_115f374f]

Volumetric fog and DOF seam to create artefacts with translucent material…The Material: Details panel > Translucency unclick Enable Separate Translucency.doesn’t work well, even for a volumetric fog (with transclucent material) …Where we can find very special but interesting artefacts here: (ue4 chalet -raytrracing - YouTube)

[NilsonLima]

@Citymmer

Volumetric fog and DOF seam to create artefacts with translucent material…The Material: Details panel > Translucency unclick Enable Separate Translucency.doesn’t work well, even for a volumetric fog (with transclucent material) …Where we can find very special but interesting artefacts here: (https://www.youtube.com/watch?v=36Qoq_kB9jk)

It is very important if you could create a small repro project (basically stripping most of the content and using replacements props) and send it using the Bug Submission Form using this link

That is the better way to make the developers aware of the issue.

[anonymous_user_115f374f]

OK, thanks, i will do it…

[AnimatedT (Tarun)]

*When using console coomands

r.VolumetricFog.GridPixelSize*
r.VolumetricFog.GridSizeZ

Are they saved with the level?
Also what are the default values of the commands mentioned above?

Thanks!

[NilsonLima]

@Tisanim

*When using console coomands

r.VolumetricFog.GridPixelSize*
r.VolumetricFog.GridSizeZ

Are they saved with the level?
Also what are the default values of the commands mentioned above?

Thanks!

The values are not saved in the level. You have two choices:

• use an execute command inside level blueprint and set them
• set the variables inside the project’s engine.ini

The default values are the one you receive as return once you type at the console the variable names without specifying a value to change them.

[Arnage]

There seems to be a bug when using world position in a light function in combination with volumetric fog. Notice in the attached images the incorrect masking of the volumetrics. The expected result would be that only the volumetrics below the cube surface are darkened similar to the sides of the cube. The issue is also camera relative, so this masking flies around the scene depending on the camera angle making this combination of features unusable.

To make matters worse there doesn’t seem to be a way of disabling the light function just for the volume fog effect. In my usecase (and I imagine for others as well) I wouldn’t need that anyway so it seem like a useful optimization to offer that option.

Edit: I submitted a bug report with an example project here on answerhub.

[Pesarkki]

I didn´t find any discussion about theatrical lighting, sorry if there is some.

But my question is:
Is there anyway to make volumetric lights with gobos like in this picture?
I already try in lightfunction material and it works in objects and surface. but not in the air.

[PoGo_DaCaT]

Hello,

I just start on ue4 and I’m working on my first project, so i want to apply a local volumetric fog, and I already follow the instructions to do it with the ue4.21 version and it worked very well, so now I wanna do this again in the ue4.23 and it doesn’t, I don’t understand why.

I made the material, I customize it a little, after that I run it through a particle, set the light and the exponentiel fog and it worked. I do all this once again, I read all the volumetric fog ue4 docs, and idon’t what I forget.

So, it will be welcome if someone can help me to solve this problem.

My computer run with
-i7 4770
-16GbRAM
-nvidia GeForce GTX 1060 OC

Thanks for your help!

[II_ADN_II]

@II_ADN_II

The problem is that you can use the volumetric fog to simulate sun rays trough the clouds. It works perfectly but only in really small scales. There isnt a reason why this shoudnt work on a real scale since the resolution of the shadows and the volumetric fog still the same. Also the draw distance of 100,000,000 is just as an example in an empty scene, unfortunately it breaks much earlier in a standard game scene with lots of assets.

Any workarround?

[vbs]

I have a project with Niagara plugin enabled on UE4.22.3 and I am following this tutorial to build a fog particle system. https://www.youtube.com/watch?time_c…ture=emb_title However, I first tried to create the material and apply it to a Niagara particle system, I’ve gotten some errors, so I deleted that particle system from content and project and went back to implementing exactly how it’s done in video with a regular cascade particle system. However, my material is getting errors related to Niagara still, and it’s not rendering properly. I’ve attached a screenshot of the material function and errors. Anything I’m doing wrong? maybe I should disable Niagara? I’m using it with another particle system that works fine, so I’d rather not…

UPDATE: I upgraded the project to 4.231 and I get the error:

[SM5] /Engine/Private/VolumetricFogVoxelization.usf(61,33-110): error X3004: undeclared identifier ‘VertexFactoryGetTranslatedPrimitiveVolumeBounds’

UPDATE 2: I disabled the Niagara plugin and the volumetric material now works… so It’s not possible to use volumetric materials with Niagara? Or should I do something different?

[inedible.red]

@Pixelpirates

Thanks for volumetric fog, it’s great. One thing I miss though is the ability to check with lighting channels affect the fog.
In a project I’m working I’m using a separate lighting channel for a couple of lights that follow and light the main character but nothing else, and as it is now those lights light the fog as well as the character.

Did you ever manage to solve this? I’m getting a similar error when using objects lighted by channels different than 0 - https://youtu.be/-1FZkZJtIvE

[inedible.red]

Is it normal for the fog to react this way for objects using any lighting channel combination other than straight Channel 0?
[video]https://i.imgur.com/ZTe0GR0.mp4[/video]

Fog

This was working in 4.22

2020 01 07 15 40 52

[presto423]

@inedible.red

Are you using static, stationary, or movable skylight or directional light (the light that’s lighting the whole scene)? It appears that using the selection box function, whether to select a character or simply starting to use it, triggers the problem. It could be something in the volumetric fog material’s settings, such as domain or if it’s not set to per-pixel (default is per-vertex). Post this in AnswerHub and see if you get more knowledgeable replies? In here it’s likely to get ignored.

[inedible.red]

@preston42382

@inedible.red

Are you using static, stationary, or movable skylight or directional light (the light that’s lighting the whole scene)? It appears that using the selection box function, whether to select a character or simply starting to use it, triggers the problem. It could be something in the volumetric fog material’s settings, such as domain or if it’s not set to per-pixel (default is per-vertex). Post this in AnswerHub and see if you get more knowledgeable replies? In here it’s likely to get ignored.

All my lights are movable. Selecting makes visible the character “selection ring” (golden circles) that’s using the lighting channel 1. I can replicate the problem by just adding a mesh in-game and switching the lighting channel 1 on and off.

[presto423]

“All my lights are movable. Selecting makes visible the character “selection ring” (golden circles) that’s using the lighting channel 1. I can replicate the problem by just adding a mesh in-game and switching the lighting channel 1 on and off.”

I have encountered a similar issue where viewing the scene from above it, or at a steep angle to it results in the lighting going super bright, at a gradual rate rather than instantaneously. I’m wondering if it has something to do with lighting channel 1. Does it need a specific setup before using it? Why would adding a mesh or using channel 1 or not cause the problem or not, respectively. Or is it another one of those ‘defies simple logic’ problems that UE4 is infamous for.

Is the scene using an LPV (light propagation volume)?