Aircraft above the clouds

[kenzor]

I'd really like to use the Vray procedural clouds system to render aircraft above the clouds.

Its frustrating that I can't move the existing clouds below me, though i understand why it can't be too close to the camera height.

Please can we have another cloud layer below the camera ?

[dimitar_panayotov]

Hi, are you talking about the clouds in the VRaySun settings?

[^Lele^]

I'd really like to use the Vray procedural clouds system to render aircraft above the clouds.

Its frustrating that I can't move the existing clouds below me, though i understand why it can't be too close to the camera height.

Please can we have another cloud layer below the camera ?

These clouds are an approximation, it's not guaranteed they can be extended as you'd like.
You can however use any VDB file, however produced, to scatter your own clouds below the plane, and those will render exactly, if slower than the approximated ones.

[kenzor]

Hi, are you talking about the clouds in the VRaySun settings?

yes indeed

[kenzor]

These clouds are an approximation, it's not guaranteed they can be extended as you'd like.
You can however use any VDB file, however produced, to scatter your own clouds below the plane, and those will render exactly, if slower than the approximated ones.

I understand the maths for these kind of approximations... That's what makes them fast . It's also why the clouds are limited to a minimum height above the camera of 500m ( because below 500m the clouds are likely look less convincing) .

However problem is the 'distance' of the cloud plane from the camera, not the height. If the camera gets to close to the clouds the approximation falls apart but, a cloud plane '500m below' the camera will look just as good as clouds '500m above' the camera.

What I'm suggesting is a check box to flip the cloud layer so that its always 'below' the camera but, is still never closer than 500m.

VDB are really really slow compaired to the approximation of the sun sky system. VDBs are slow to render, slow to generate, and time consuming to art direct. They look great when its all set up but, its really time consuming to get there.

For most situations, if I'm high above the clouds, I don't need the rendering detail of VDB volumetrics. I need the speed and adaptablity of an approximation.

[^Lele^]

I had a similar request a while back (ligthing didn't adjust with viewer height in the new sky model), and was told it would be tricky indeed to implement: i am reporting you what i was told by the developer of these.
The wish is noted, but it's unclear if it will be doable (to be read as: it wasn't an oversight. It's a limitation.).

VDBs are eminently usable, and there are a ton of libraries out there with clouds, free and paid.
They are not as quick as the approximation, of course, and won't ever be, but they aren't slow if one needs some background clouds, either.