Better env fog examples and documentation

[SonyBoy]

Once again I'm utterly confused about the correct methodology for working with fog. Would it be too much to ask for some PRACTICAL examples of how to set up, say, a set of rect lights on a vehicle in a foggy environment. All the examples given in the docs are completely abstract and more or less useless. The language is confusing (e.g. the types of light settings on the fog itself are completely impossible to understand), the attributes are confusing with overlap between things like density and transparency. Fog height seems to have no effect on the appearance of fog in light volumes. What's the difference between a widget and container? The questions are just endless. It's clear that env fog can get some nice results, but every time I use it I have to spend literally hours trying to unravel the intended workflow.

[damaggio]

Hi SonyBoy, Chaos has introduced a few more parameters so it's easier to tweak the look for any specific scenario, I actually find very easy to set it up , I have saved a few presets to start on a new type of environment, that way the parameters might be closer to a certain job and you can refine from there.

Remember to check the docs fully, some of your questions are very visible there and there's even the recorded workflow....here's a very important one not to skip.. " When the fog is added to a gizmo, the Height parameter has no effect. When the fog is added to the environment or in a container, then the Height parameter determines the starting point in scene units."

A key thing to remember in my examples is that it's for film production and we keep in centimeters the Maya default unit so these images are from the default real word scale in Maya, if you like working in other unit size you'll need to experiment with different values.

........but as a well known rule "Never change Maya units to anything else other than Centimeters"

In this example an average building is 3000 units/ centimeters =100 feet tall so I would need at least 4000 units to go past the height of these buildings, if I had high rises like in NYC would have to go beyond 3 times that value for a wide shot, although in that case I would use Aerial Perspective instead for better results.

For lights it is straight forward as long as they are inside the fog height to cast beams or even God rays, you don't need to attach to a gizmo/ cube container, it will work the same way but you can definitely try that, I just find it easier as an infinite fog even if my camera is inside a room (I'm not really sure about rendering times, never made a comparison between the 2 options)....there are more settings that I don't have time to discuss here but is well explained in the docs such as light linking , etc.

In general once you know the most basic settings it will be easy to fine tune the fog to what you desire, don't be distracted by parameters that might do the same thing, some have sliders now and is faster to tweak. I hope that helps you a bit, I'm no expert but I use almost daily for Film concept images " Everything has a bit of haze" and I'm sure the ArchViz users will chime in with their notes sooner or later and maybe both of us will pick up new tips.

Just run your own tests specially now in IPR and new cards feels almost like real time.

The most used settings typically are Color, Fog Distance,Fog height. (Scatter GI if enable will give you more bounces but at a rendering cost)

Take a look at some examples I rendered so you can see some variations and again remember to save a Generic preset as a starting point and save a default Preset as well so you can go back to its original values .

As a final note I still think there's more room for improvement with Environment fog, in Vray 6 ,Chaos made it a bit faster but I'm still on Vray 5 and achieving God Rays like in Unreal engine is just not the same, it's very faint

looking unless you take into compositing, I wish it was as strong as Unreal God rays . Have a good wek.

[damaggio]

No Gizmo for the garage image
This excellent video tutorial by Carlos Alvarez covers in detail some other features including a gizmo https://www.youtube.com/watch?v=TqwPNHIIXgo

[matthew999]

Hi Damaggio, the garage scene looks great. How did u make it so the fog doesn't have any opacity when the light from outside is occluded by the building. Is there some post processing here? When ever I try this the fog has too much effect in the interior that it outside of the volume of the god rays.

[damaggio]

Thanks Matthew, no the fog has nothing special to it ,no physical camera... it's just Environment Fog plus a Maya directional light, fog height 4000 and distance 120000, I did add a render element "Atmospheric Effects" and then I overlayed that onto in Photoshop in screen mode to punch up the god rays that looked a little faint and then tweak levels a bit, I didn't want to blow out the sun glare on the window, ( I wasn't sure if that would happen in a real photo since the sun is not directed at the camera)...I did want to see a little hint of the water tower thru the late afternoon lighting. You just need to do a lot of render tests and fog tweaks. When you crunch the levels a bit it tends to kill a bit the fog inside the room, now looking at it again maybe the garage could have a bit more haze on the inside...oh well.

[matthew999]

fantastic explanation cheers

[intercard]

No Gizmo for the garage image
This excellent video tutorial by Carlos Alvarez covers in detail some other features including a gizmo https://www.youtube.com/watch?v=TqwPNHIIXgo

I’m very happy that you like my video tutorial !! Hihi thanks And many hugs !!!!

[damaggio]

Yes indeed....keep'm coming Carlos.