Does scale matter with Octane Fog Volume ?

[lalalem]

Hi,

I made a landscape with World Machine and I imported it into C4D at close to real world scale (mountains 90 meters high, 500 meters long landscape) because I will model houses as well.

I want to add an Octane Fog Volume, but I realise I will need it to be HUGE in order to cover the entire scene at scale. Will this be an issue ? Should I scale down my project because of the volume ?

Thanks !!

[bepeg4d]

Hi,
which kind of fog effect do you need to obtain?
Better to use Environment Medium fog with landscape scenes.
ciao Beppe

[lalalem]

Hi bepe,

The fog effecft I'm after is something like this : https://imgur.com/a/8Ki0HQk where the landscape kind of fades in the distance.

I tried adding an Octane Texture Environment and hit "add fog" but it's not the same. The fog fills the entire scene instead of being scattered in the distance.

I was following David Ariev's mars environment tutorial in which he uses Octane Fog Volume, but his scene is way smaller than mine, and my C4D keeps crashing because of the size of the fog volume I need.

[frankmci]

I know it's an outdated method, but if I'm not using a Z Depth pass to add fog in post, I like the old "medium applied to a specular material object in front of the camera" trick. I find it quick and easy to control, and gives good visual feedback while blocking out the scene. I know it's overkill, but I apply it to a truncated cone (covering the full FOV) that's a child of the camera so I don't have to worry about positioning the fog object. It's probably not as physically accurate as an Octane Fog Volume object, but this way doesn't really care about scene scale and renders fast. It's a technique from the Octane 2 days, but still works fine.

edit: I should mention that I've got the fog cone visibility turned off in the Editor in these screen shots. It's just a standard cone primitive sized to be slightly bigger than the camera FOV.

[bepeg4d]

If you want to use the Environment Medium, the most important value is the Medium Radius (in meters) that defines the radius of the virtual fog sphere around the camera, try with a very large value greater than the distance to the far mountains, with a very tiny value in the density.
ciao Beppe