CompuServe Thread

#Opacity map – problem

8 messages in this thread
#105041From: KeyframeJun 1, 1994 4:49 AM
Greg, We have come across a strange problem within 3ds r3 and that is that when using opacity maps to either fade in or out objects or even just to put a logo on an object , the transparent area (black) does not becom fully transparent, it leaves a slightly opaque area as if the colour was dark grey instead of black.. Any ideas would help us greatly Phil
#105059From: Jonas Ruikis [ADESK]Jun 1, 1994 7:58 AM
Keyframe, << …within 3ds r3 and that is that when using opacity maps to either fade in or out objects or even just to put a logo on an object , the transparent area (black) does not becom fully transparent, it leaves a slightly opaque area as if the colour was dark grey instead of black..>> With R3, a ray trace light will make the transparent area clear *and* will properly cast a shadow of the non-transparent area. You'll notice that with a spot, the shadow cast is the outline of your geometry including the transparent area. jonas[adesk]
#105087From: David J. MarksJun 1, 1994 10:04 AM
>> Any ideas would help us greatly PMJI, but try using the same map as a shininess map, so that no highlight appears on the transparent area. Also, I believe you should check the ADD/SUB buttons and try SUB to give you complete transparency. Finally, in your 3ds.set file, make certain you are setting NEW-SUBTRACTIVE-TRANSPARENCY = OFF. (Please check the syntax, because it might be wrong. I just can't get to my 3ds.set file from this workstation.) The new transparency gives richer colors, but won't go fully transparent.
#105106From: KeyframeJun 1, 1994 11:17 AM
Thanks for the soloution, it works a treat, but does anybody know if the problem will be solved in the future?? Cheers. Phil..
#105158From: David J. MarksJun 1, 1994 4:41 PM
>> it works a treat, but does anybody know if the problem will be solved >> in the future?? Which item fixed you up? I don't think it's a "problem" as you suggest, but rather just taking advantage of and understanding the available features of the software.
#105265From: KeyframeJun 2, 1994 3:51 AM
It was a flag in the 3ds.set file that changes from r2 transparency to r3 Phil
#105321From: Yost GroupJun 2, 1994 10:36 AM
The New-Subtractive-Transparency parameter in the 3ds.set file is not an R3 transparency algorithm as opposed to the R2 transparency algorithm. It's simply an _alternative_ system for subtractive transparency. It was developed very late in the development cycle and, as a result, is not in the 3ds interface. Nevertheless, though it has some flaws (as you've noticed), we didn't want to throw it out, so we included it as an option in 3ds.set. You'll notice, however, that it is _not_ the default setting in 3D Studio. We recommend that you use the standard subtractive transparency unless the new system provides an effect you simply can't live without. – Jack
#105356From: KeyframeJun 2, 1994 12:30 PM
Jack, Thanks for the reply. Phil