View Full Version : Twisting clip tree shadows

08-12-2004, 03:26 AM
I create quite a few landscape visualisations. I used to create real 3D trees but recently decided that using singly poly clip map trees are far better.

When im animating these scenes I make all trees point at the camera. This works great apart from as the trees near the camera twist the shadows twist as well giving a strange thin-fat-thin shaddow as the singly poly rotates.

These are quite low budget jobs and (I know im asking for the moon on a stick)im seeking a quick and easy solution to this. I may just have to turn the tree shadows off.

Thanks for any help.


08-12-2004, 06:51 AM
use two intersecting polygons for the trees instead of one.

08-12-2004, 06:54 AM
That could be worth a try. Thank you.


08-12-2004, 09:54 PM
Since the trees don't go anywhere you can use faked shadows -

Duplicate your ground plane, turn it white and set it's alpha channel (adv. tab) to 'shadow density'. Remove anything that moves during the animation, set everything else to 'unseen by camera' except the ground plane and save this as a shadow-setup scene. Get your shadows looking really nice, you'll only be rendering 1 frame so you don't have to worry about render times. Place a camera in the sky looking straight down with a field of view that fits the ground plane and render the frame. Tweak this image in Photoshop to improve the shadows even more and use it as a texture layer on the ground in your main scene - this will save a lot of render time and give you better shadows at the same time.

08-13-2004, 08:57 AM
Thanks very much for that.

Its looking like im going to have to do something like that.


08-13-2004, 03:27 PM
I haven't tried this but it might work. Ill try it later at home. Expanding on faulknermano's idea, maybe you can get the second (intersecting polygon) to always point at the light that casts shadow (or any other object/null of your choice) and then make the polygon unseen by camera (invisible). The shadow will still be generated by that invisible polygon and it should be cast the same, no matter where your camera is, and no matter where the first (visible) tree polygon is facing.

Just an idea