View Full Version : Shadows from nowhere!

11-04-2009, 10:20 PM
I always thought that Lightwave couldnīt make an object with 100% opacity to receive shadows from other objects in the scene. Stuggled with it in post instead which I consider to be kind of stupid if this really works in LW.

So is there any way I can make a transparent object to receive shadows from other object in the scene in Lightwave I would be glad to hear about it, and a lot happier if someone could tell me how to do it.

I couldnīt find any valuable information about this on Internet and only good knows how many pages of the old Lightwave manuals are left over after the rats had years of excellent meals in the garage. I hesitate of enter the garage nowadays because I heard some roarings and stomps in there lately, must be the killer rats... :D

P.S. I guess that if itīs possible for a 100% transparent object to receive shadows it probably also is possible for this object to cast shades.

11-04-2009, 10:41 PM
What effect exactly are you trying to achieve here?

11-04-2009, 11:36 PM
I suppose you could render the image once without the transparent object, and then render it a second time -but- you now project the previously rendered image/animation onto the "transparent" object (although this time it would be opaque) so then it could receive a shadow.

Just an idea. Let us know how it goes! :thumbsup:

11-05-2009, 12:57 AM
What effect exactly are you trying to achieve here?

Yeah, what look are you after? If it's simply any shadow on a 100% transparent surface, just turn up the spec. E.g., like below.

11-05-2009, 01:14 AM
Something that could be easily achieved with a simple composite too. Again, it depends on what the desired effect is.

11-05-2009, 01:58 AM
What I was asking for is if thereīs a way to make an object receive shadows if the box "hidden for camera" is chosed!

See attached images!

11-05-2009, 02:14 AM
It's not something LW can do for you out-of-the-box, because in order to see shadows on an object, you have to see that object. It would be great if someone wrote a shader or made a node tree to do this, since so many people want it.

In the meantime, the procedure is to set the alpha option in the ground's surface to 'Shadow Density', then composite the render onto another image. Areas with no shadow will have no alpha, and will be transparent in a composite.

11-05-2009, 02:44 AM
Try this - load these nodes and plug the Logic-out into the transparency channel. It's a bit of a hack, it won't work for everything since it's based on shaded color instead of actual shadow information, but it might work for this.

11-05-2009, 05:41 AM
Here's something I came up with to put shadows on a plane. I used occlusion and lambert nodes to drive the transparency of a black (dark shadow) surface. I made this so I could have the shadows and the object in one layer for one-step compositing. You can't have 'unseen by camera' checked for this to work.

11-05-2009, 03:16 PM
Wow... thanks for the help! Iīll take a look at these...