CompuServe Thread

#decal question

8 messages in this thread
#187684From: HAROLD KALMUSAug 28, 1995 1:44 PM
I'm creating a perforated ribbon (curved flat plane) which is suspended in a room. I've made a bitmap of the perforation grid consisting of a white background and top and bottom border. When I map this to the ribbon face and render my white perforation pattern renders black, not transparent. The top left pixel is definitely white. I'm missing something obvious here (I've done this successfully before) but can't figure it out today. Any help will be greatly appreciated. Thanks Harold
#187710From: CSA/CAAug 28, 1995 3:02 PM
Harold, Sure your material is set to DECAL? Kevin Krell – Computer Support Associates
#187742From: HAROLD KALMUSAug 28, 1995 5:21 PM
Yes, my material is set to decal, my green and white map is rendering green and black. It is however set to tile and decal. Thanks though, sometimes the most obvious is the most difficult to find. Harold
#187790From: Larry MintonAug 28, 1995 9:48 PM
3ds Reference manual, page 9-49: When you use either "Decal" or "Both". the transparency of the bitmap pixels is determined by the contents of the bitmap. If the file contains an alpha channel, the alpha channel is used for transparency. If the file contains only the RGB color channels, the color of the pixel in the upper-left corner of the bitmap determines the transparent areas, and all pixels in the bitmap containing the some color value are treated as clear. Sound like your situation? LAM
#188048From: HAROLD KALMUSAug 30, 1995 8:02 AM
Larry, Read it and did it (and even understand it). But it still isn't working. I even put a big red box behind the mesh to see if it shows through the black. It doesn't. Again, my bitmap is a green pattern on white, the upper left pixel (and the whole border) is white. The white renders black? Thanks, Harold
#188093From: David J. MarksAug 30, 1995 12:18 PM
>> Again, my bitmap is a green pattern on white, the upper left pixel (and the whole border) is white. The white renders black? << The upper left pixel color (white in your case) becomes transparent in the map, revealing the underlying color (set in the ambient/diffuse boxes). To fix your problem, slightly change the upper-left pixel -OR- set your ambient/diffuse colors to white. – Dave
#188524From: Grahame NaylorSep 1, 1995 9:39 AM
Are you confusing the functions …. Transparency… seeing through to the diffuse colour of the object. with opacity…. seeing through the object to the scene….. ? if so you need to put your map in the opacity slot. Grahame
#188826From: HAROLD KALMUSSep 2, 1995 9:36 PM
Thanks Grahame, that did the trick. I knew it was something really simple, sometimes the things in front of your face are the most difficult to see. Thanks again, Harold