CompuServe Messages

>>Am needing to render shadows of modeled text on a background(which I have found to unstable to map to a rectalinear face<< Ian, Heres a solution I used once to create shadows on a non-mapped background image that gives a high degree of control on the shadows appearance, the only trade off is a lot of overhead. Step 1. (create a alpha image for shadow projection) Set up your scene as you normally would and pick a single spotlight that is going to cast your shadow. For speed purposes, turn off the spotlights cast shadows option. Setup a viewport to view your object though the spotlight and render your scene through this viewport with ALPHA on and SPLIT, (the alpha files will become a shadow projector in the next step). Step 2. (create a RGB mask for VPOST) Create a flat panel object behind your logo object that could represent a backdrop or background. Create and assign a material for this panel that has RGB and Lunimance values of 128 across the board for Ambient, Diffuse, and Specular. Do not give the material any transparency values. Once the panel has it's material assigned HIDE your logo object. Now for the tricky part…Create a perfect clone of your spotlight and call it projector. Adjust this new spotlight so that it projects your alpha image created in step 1. by setting the name of your alpha file in the projector option of the Adjust Spotlight dialog. Turn off the original spotlight and any other spots or omni lights in the scene. Render your scene through the camera viewport with the APLHA and SPLIT options off. (What this step should create is a grey skewed projection of your text onto a flat black panel object. The brighter the projection of the alpha image the darker your shadow will appear in the final step, you will have adjust your RGB and Lunimance values to give the shadow a transparency you desire in the final image. The reason for the clone spotlight is that you may wish to dolly the clone's target location closer to your background panel inorder to reduce or control the projection coverage.) Step 3. (final rendering) Now that you have your aplha shadow projection from step 2 you need to UNHIDE your logo object and HIDE the panel object. Turn back on the original spotlight and turn on it's cast shadows option (the cast shadow option is only for shadows that need to be casted onto itself or any other objects in the scene, minus the hidden panel). Turn off the clone spotlight. Enter Video Post in the camera viewport and set up two Queue keyframer entries. Edit the first entry so that it references your desired bitmap background. Also, edit the first entries Alpha column to contain the following: RGB MASK = bitmap created from step 2; Intensity = on; Neg Modifier = on; Opacity threshold = 255 (this value can also be adjusted based on shadow intensity desired.) Leave the second Queue entry as KF scene. Render final animation. Summary: Yes, this is a verly lengthly process with a huge overhead, but it is very diverse in that you can easily use it for animated shadows and it's control over the shadows final appearance is very flexible. If anyone knows of an less complex method that allows for a high level of control please let me know. Roy Baker.