CompuServe Thread

#Opacity map not Transp.

8 messages in this thread
#193158From: John N. JordanSep 29, 1995 12:17 PM
I'm having some trouble using a opacity map to cut out a flat object, it seems that pure RGB black isn't 100% transparent.. is this a "feature" or an error on my part? I'm using an RGB TGA file for the grayscale transparency map, since I used this successfully before. (I know it doesn't make sense) I got 3DS cutting out shapes before (after many test renders, file formats, etc.) but it's not working now. The maps are high rez (~1k), and are used to cast raytraced shadows.. I have several maps to do, and it'd take too long to recreate them in a vector program, but I would prefer a mesh over opacity raytracing. Any info would be appreciated. JNJ
#193161From: Paul Sanford [LVL5]Sep 29, 1995 12:23 PM
John, Can you see part of the object, or is the light not penetrating correctly? If it's the first, make sure you've copied the opacity map to the shininess slot, perhaps as a negative mask, depending… Paul S.
#193162From: John N. JordanSep 29, 1995 12:32 PM
Paul, The main part is showing correctly (a logo), but there is a transparent (red) area that should be cut out with the map. This highly transparent area continues all through the flat object, revealing that it's mapped on a rectangle. (spoils the effect. <g>) I'll play with the shineness spot, but one regular map and one for the opacity is all I've needed before. Thanks for the quick reply. 🙂 JNJ
#193172From: Jonas Ruikis [ADESK]Sep 29, 1995 1:00 PM
Hi John, << not quite transparent..>> What's you file input gamma set to? You may be shifting 0,0,0 up..
#193181From: John N. JordanSep 29, 1995 2:30 PM
Hi Jonas, >What's you file input gamma set to? You may be shifting 0,0,0 up..< will check. What should it be? <g> JNJ
#193182From: John N. JordanSep 29, 1995 2:31 PM
Jonas, >What's you file input gamma set to? You may be shifting 0,0,0 up.. It's set to 1.8 JNJ
#193198From: Jonas Ruikis [ADESK]Sep 29, 1995 4:19 PM
Hi John, << 1.8 for input file gamma..>> Reread the advanced user guide on Gamma. Try changing file input gamma to 1.0 and rerender. Post your results.. jonas[adesk]
#193592From: John N. JordanOct 2, 1995 5:51 PM
Jonas, >Reread the advanced user guide on Gamma. Try changing file input gamma to 1.0 and rerender. < I ended getting it working using black for the map areas being cut out (instead of red and blue, which they were before) The transparency isn't noticable then. I'll re-read, and try the 1.0 gamma monday, and get back with you on how that works (with a colored map in the cut out areas) That's probably it. (I forgot about the effects of gamma on a opacity map.) Thanks, JNJ