CompuServe Messages

#Need Help for a friend..

    16-Feb-95 10:37:29
Sb: #Need Help for a friend..
Fm: Brendan Gallagher 73004,1033
To: Jonas Ruikis [ADESK] 73172,1351
CC: Compuserve 3DS Forum Jonas, These are 2 questions that a friend of mine needed an answer for. He does'nt have a modem at this time but I was telling him that 'Asoft' forum is worth the price of one itself. If someone could help with this I would appriciate it … 🙂 Brendan G. Hi, there are a couple of problems I have run into using 3DS rel. 3.0 I hope someone can help me with. #1 concerning using alpha channels in video post to composite imagery: When I generate the alpha channel by saving a 32 bit targa file in Adobe Photoshop 2.51 for windows and then using Queue alpha channel to composite the images I find that the image seems to rip or be offset at the edges on one side when I render the images. When I generate the alpha channel in 3DS I dont run into this problem, is there some differance between the way these two applications save this information and is there some way to correct this? #2 concerning the creation of shadow maps in scene: I have a scene inwhich there is a lighting effect of a self illuminated sign that casts a slightly larger shadow map of itself on a wall. In order to create both the glow of the sign and and the shadow of the sign on the wall I have created an object which rests slightly behind the face of the sign that utilizes an opacity map to create a glow around the sign while allowing the building behind to show through. This object is shaped so as to cast a shadow map on the building while still allowing the building to show through, a rectangular spot light being used to generate the shadow map. I noticed that when I merged this project with an airplane taking off behind the building it wreaked havoc on all the shadow maps of the signs in the scene. The airplane while it was in the camera view and only while it was in the camera turned off the shadow maps in the scene at specific frames of the animation I was working on. This effect was repeatable at a specific frame of the animation and when I moved the camera and the keys of the airplane the effect would shift to other frames in the animation. I excluded the airplane from the lights that I used to cast the shadow maps on the building and excluded the lights illuminating the airplane from the building and still ran into the same problem. I could only rectify problem by eliminating the airplane entirely from the scene atwhich point everything behaved as it should. I generated the the two scenes, one of the airplane and the other of the building and signage as separate projects and then merged them and I wonder if the problem lies therein. Thanks, John