Do you think you can make it so the clouds can be affected by lighting as well as cast shadows? That way the clouds won't be all completely grayscale.

I think this can be done by having the clouds be two layers, one being $translucent 1 and the other being invisible but still casting a shadow. If $Nocull is in there you could get lighting from the other side of the cloud as well.

The clouds themselves are full-bright as they were intended to be used on gm_black (the go-to scenebuild map where total darkness reigns).

As for casting shadows? I don't have much experience with vmts and such but considering that the clouds are images slapped onto flat planes, I think the game will only account for the plane, not the cloud texture itself (aka big square shadows).

I will experiment around with it and see if I can come up with something though.

I managed something a while back using alphatest on planes in sfm.

$Alphatest would allow for shadow casting on alpha'd textures but the edges would look rough, which is why I would then suggest making that invisible but still casting shadows, while pairing it up with $translucent enabled non-shadow casting plane of the same texture. bump mapping would then make the lighting prettier as clouds are 3d in nature irl.

Whatever you can manage, thanks!

This first image is a rough idea of what I'm trying to accomplish

https://imgur.com/njgzznk

This second image is the three planes split up.

https://imgur.com/BnJQphL

The one on the left needs a bumpmap, $nocull, $phong, and $translucent. Also VertexLitGeneric. Could get prettier with lightwrapping and phongwrapping but those can be worked with later.

The one on the right is the same, but the image is reversed, and the plane is actually facing away from the viewer, so it actually catches light coming from behind it rather than in front like the one on the left is.

The one in the center has the same settings BUT instead of $translucent, it uses $alphatest.

The left one is .1 units in front of the center one, and the one on the right is .1 units behind the one on the right.

If you need the clouds to be fullbright for scenebuilds on dark void maps, then you can do that with a second skin, one for unlitgeneric and vertexlitgeneric

Went around on a discord server asking for help regarding this matter : https://imgur.com/a/3xfE8c0
Basically, it won't work, or at least, it won't look good when making your scenes

There IS an alternative that was suggested by the same person :
You could apply an inverted cloud texture on a lamp to fake the cloud's "shadow".
I'm gonna make some lamp textures like these and see wether it works or not

I agree with the first suggestion on here, it is impossible to make lightning storms with the current clouds because they aren't affected by lighting.