Clouds shadow casting from HDRi

[MANUEL_MOUSIOL]

You know when the sun hits clouds and those cast beautiful shadows on the ground? Now if we use an HDRI for lighting we will never get these shadows but only soft lighting. I was thinking if there was a way to (more or less automatically) create clouds with Phoenix or other methods that are based on the Dome Lights intensity or so so we can get the shadow casting...
Actually I am working on an animation with a timelapse of 585 or so frames and it would probably be a lot of work to hand-create those clouds accordingly to the HDRi... but I would really love to get this last kick of reaslism into my rendering.
Any thoughts?

[urbanite]

just put the plane to block the sun, closer to the ground if you want sharper shadow. that would be my approach if I need this scenario.

[MANUEL_MOUSIOL]

I am not looking for sharper shadows though but for shadows cast by the clouds, that usually more or less subtle patterns.

[pokoy]

Would a simple plane with an noise (animated if needed) in the opacity slot do the trick? The plane should be set to be invisible to camera/reflection/refraction but would still create a shadow. You'll have to play with the noise until it looks good but I think it should work.

[Neilg]

Go with noise in the opacity slot of a plane - simulating accurately dense clouds and scattering light through them just to get some shadows on the ground is like going after a fly with a sledgehammer.

[MANUEL_MOUSIOL]

You are right. I was unde thinking.
coming from photography, I am always striving for the most realistic reault possible . It bothers me a little to fake it with random noise... But it's probably the best solution...
Thanks, guys .

[Neilg]

I am always striving for the most realistic reault possible .

You'd be amazed how realistic noise in the opacity of a plane can look. it's absolutley perfect for it and can be set up in no time, with simulated clouds you'd spend days fucking around trying to get it to look how it does in real life.

[MANUEL_MOUSIOL]

Sure, totally agree .
there are certain constellations, patterns - like stretched clouds - that find a bit hard to create procedurally alongside other patterns. But that's the way to go.