How to get rid of this Fog "HARD" edge?

[IzaFly]

[shot]http://www.itsflybye.com/public/images/games/UT3/Dawnv2/Dawn48.jpg[/shot]

Is there any way to prevent this?

I'm playing with multiple fog layers,and I'd like it to be really dense in the lower canyon, and thinner as it reaches the top. But when I go up in the lower fog layer, you can see the ugly hard line from it.

[ShadeMistress]

add a couple more heightfogs in progressing density closer together between the two?

[Setheran]

For the lower fog it might be better to try the fog static meshes that some of the official maps use (look around Avalanche's caves or Heatray's skyline for examples). I've not used these myself yet so I'm not sure how to get it looking right or how it'll affect performance, but the effect it creates seems in line with what you're looking for.

[IzaFly]

Yeah, I've played with the fog static mesh. Thing is, that entire area is where players go through. The static mesh wouldn't feel like real fog down there.

[DGUnreal]

I would not use multiple Heightfogs to attempt to achieve this. You are going to start impacting framerate due to the fog particle rendering time.
FogVolumes have the ability to show a softer edge, but you have to be careful on their size or performance suffers.
Personally I would stick with a single Heightfog in the map.

[IzaFly]

Oh ok. I'll just leave in one fog volume.

How would I go about softening up the edges?

[DGUnreal]

You are using a HeightFog and not a FogVolume are you not?
HeightFogs always have the distinct edge if they are set to have a thick fog amount.

[IzaFly]

Yes, this is a heightfog. Unless I am mistaken, FogVolumes are only meshes with a semi-transparent material applied to it, right? I played around with a few of these meshes and materials, but I did not achieve the desired result. The fog like appearance would only occur on the edge of the mesh. I need it to be foggy throughout the entire volume in order to simulate real fog.

I tried lookin for information on FogVolumeConstantDensityInfo, FogVolumeLinearHalfSpaceDensityInfo, and FogVolumeSphericalDensityInfo, but I could not find any specific info on how to apply such a device.

[DGUnreal]

A FogVolume uses a bounding mesh to determine the area (volume) that the fog will fill.
You place a closed staticmesh such as one of the simple primitives available in one of the packages, place the desired FogVolume*Info actor, specify the staticmesh as the FogVolumeActor in the FogVolume*Info actor property.

FogVolumeConstantDensityInfo does precisely that, it fills the mesh volume with a constant fog density.

FogVolumeLinearHalfspaceDensityInfo is similar to the HeightFog but can be rotated, plus the fog density increases linearly from the actor origin.

FogVolumeSphericalDensityInfo has max density at the center falling off to the radius extent.

[IzaFly]

Alright. I desperately tried doing this myself with no luck. Here is what I did:

1) Went through this route:
Actor Classes>Info>FogVolumeDensityInfo>FogVolumeConstan tDensityInfo
and placed that actor on the map.
2) Opened the "FogVolumeConstantDensityInfo" Properties box.
3) Under the "FogVolumeDensityInfo" section, I went to the FogVolumeActors.
Next to [0] there was nothing. I currently have a cube mesh selected in the generic browser, and so I clicked on Use Current Selection in Browser.

I see no fog volume. And what is displayed in the line for the fog volume actor is:
FogVolumeConstantDensityInfo'WAR-dawnbeta02-51.TheWorld:PersistentLevel.FogVolumeConstantDensi tyInfo_7'

I thought it would show reference to the simple cube mesh but it does not.

Please let me know what am I doing wrong. I found one of these fogvolumes in a stock map, but it, too, did not seem to even have a fog within a volume. Of course, view fog is turned on.

[ffejnosliw]

You need to place the static mesh in your map. Then, once you have the properties of the FogVolumeConstantDensityInfo open, lock the properties window using the button in the top left of the Properties Window. Then, select the static mesh actor in your map you want to use as the fog volume actor. Go back to the properties and press the Use Current Selection In Browser button for the FogVolumeActors property. That should assign the static mesh as the fog volume actor. Then you can unlock the properties by toggling the button once again.

[IzaFly]

Ahhh!!!

Yeah, I had the mesh in the map before, but didn't see how I could possibly select it.

Thanks!!

[IzaFly]

Alright...is there any reason why the ApproxFogLightColor is not changing the color of the fog, or am I asking for too much now.

[Drimiad]

I had the same problem. The ApproxFogLightColor doesn't seem to affect the color of the fog. Instead I went into the mesh properties and found an override material there called "EngineMaterials.FogVolumeMaterial". This is where the blueish fog comes from.

So I created my own material to use as the override material for the fog volume mesh. I connected a Constant3Vector to the Emissive port, set the material to BLEND_Additive and MLM_Unlit, and checked bUsedWithFogVolumes. Then I could control the color of the fog with the value of the constant.

That seems like a lot of trouble just to change the fog color. I get the impression they expect you to use height fog, since this mesh-based method seems to be used very rarely in the existing levels. I had to load like a dozen levels before I found a fog volume being used.

[DGUnreal]

I had answered this in another thread if search was used.
The FogVolume*Info actual fog color is set by the material, the fog actor's color property should be set similar to the material color as that is used for coloring on translucent objects in the scene touched by fog etc.