PDA

View Full Version : Seeking advice on casting shadows.



4dartist
01-17-2012, 03:42 PM
I have a sphere inside a sphere. The outer one is a cloud layer. How do I get the outer layer to cast a shadow on the inner layer?

I looked up the VStack in the manual and it makes a little sense but not enough to understand how to do this. The thing is I don't want to make my cloud layer double sided.. Is there a way?

I just made a super simple scene with a gray sphere and a procedural driven cloud layer using transparency. I still can't get these clouds to cast shadows without being double sided...

nickdigital
01-17-2012, 03:52 PM
If the issue is seeing the clouds on the back side you could run a clip map down it. So the polys facing you will render and the polys on the back side won't.

See the attached.

4dartist
01-17-2012, 03:54 PM
Thanks, let me look at this.

Edited: Because I'm an idiot.

safetyman
01-17-2012, 03:55 PM
You may also have to select "double sided" for the cloud texture (at the bottom of the material editor window).

4dartist
01-17-2012, 03:57 PM
You may also have to select "double sided" for the cloud texture (at the bottom of the material editor window).

Do you mean the surface editor? The thing is I don't want the cloud layer double sided, when I make it double sided it keeps causing render errors..


Edit.. ok I finally figured out why using double sided was bring results that were bad. It was because the clouds weren't set to receive a shadow, thus making the backside light up. I was also confused because I had to check 'exclude from VStack' on the atmosphere and clouds or else the dark side edge would render some light. But I think I have it all set correctly now and using double sided isn't so bad. I would rather have it off, but so far it's looking ok.

Thanks for your advice guys.

4dartist
01-17-2012, 04:34 PM
If the issue is seeing the clouds on the back side you could run a clip map down it. So the polys facing you will render and the polys on the back side won't.

See the attached.

As far as I can tell that sort of setup doesn't really hold up if you move the camera around. You'd have to link the clip map to the camera or something. I guess I could always have a double side cloud layer render but unseen by camera and a single sided one just render. It may take longer to render like that, but could effectively solve the problem.