View Full Version : Incidence with nodes

Gary Wales
05-10-2007, 04:40 AM
Hi - I wonder if any of the regular boffins here can help?

I'm trying to cast a *moving* light (the sun) over a model of the earth. When the light shines on the surface I want a daylight image map, and where there is no light I want a night time image map. I can do this easily using the conventional Surface Editor, but I've got myself in knots when it comes to doing it using the Node Editor in 9.2.

I start out methodically and rationally, but then I reconnect an input to experiment and it's all shot (need a footprint feature in here I think!).

Thanks for any help!

05-10-2007, 05:37 AM
Use a material mixer node with two materials plugged into it for the different states, then feed a lambert node into the alpha or into a gradient node (to control the hardness of the terminator) which feeds into the alpha.

Gary Wales
05-10-2007, 05:54 AM
Cheers Dodgy!

I think I've 'stumbled' upon another way too:


05-10-2007, 03:19 PM

You can drive the opacity of the Mixer directly with a Incidence; or to control it better; feed the incidence into a gradient node and feed that node into the opacity of the Mixer node. The two image nodes can feed the mixer node directly.

If you have access to the Beta forums, click this (http://www.newtek.com/forums/showthread.php?t=63517&page=3) link. Scroll down and I have posted my node trees (collasped). It should give you some ideas; mine is pretty complex; but you should get the basic idea on how to do it.


Gary Wales
05-11-2007, 02:43 AM
Good grief man! How did you get your head around that?

05-11-2007, 06:35 AM
That is one sexy node tree.:)

05-11-2007, 08:21 AM
Trust me, I have permanent brain damage as a result. ;) Lets just say that ever since 9 was release, I've been working on that project. Lots and lots of test renders also. About the only thing I dislike about the incidence nodes is that everything works 0-1, instead of 0 to 90 (or 180 now) degrees.

It actually looks a lot more complicated since I have a quick switch in there to turn off the city lights.


05-11-2007, 01:14 PM
I've just purchased LW and of course upgraded to LW 9.2. Is there a way I can get access to the beta forums? I'd like to take a look.

05-11-2007, 01:16 PM
I think you need to sign up in the registration area on the web. Usually takes a few days before you can access the forums.