CompuServe Thread

#Impossible Material!

16 messages in this thread
#187984From: REZA DASTMALCHIANAug 29, 1995 7:05 PM
How do you make a transparent material with only a little opacity on the outer edge? I've tried the obvious thing by setting 100% trans. INside but still that gives me to much opacity in the middle. What i must have is mostly full transparent all over with gradual opacity near the edges only and as it stands i cannot do it with 3DS. Any ideas? -Reza
#188004From: Tyler ColwellAug 29, 1995 10:10 PM
Hi Reza, if it were me I would create an opacity map in Photoshop by starting with a black image and airbrushing a soft white border. This enables you to control where the opacity is and how much.
#188037From: Ronald K. LussierAug 30, 1995 6:51 AM
>>How do you make a transparent material with only a little opacity on the outer edge? . . . . What i must have is mostly full transparent all over with gradual opacity near the edges only and as it stands i cannot do it with 3DS. Any ideas?<< Hi Reza, If I understand you correctly, you want the falloff to occur from around the edges of a (rounded) object, no matter which way your looking at it(?) – A change in the surface's opacity according to how parallel or perpendicular that surface is to the view. . . . Just like Trans.Falloff _does_, right? Except that 3DS doesn't make it to completely transparent. Yes, that is the case, unfortunately. I've been wanting exactly the reverse. Completely transparent _edges_ resulting from using falloff. And a Bias control for where the center point (of the fade) occurs. This could produce a great glow effect for many situations. And your "edging" effect. If your not moving around the object, than you could fake it with some tricky mapping (or use MeshPaint 3D . . . paint the edges in white on black, then switch that map to opacity). If it really has to be a 3D effect, I think we're both out of luck, for now. I was never able to come up with a solution. (If anyone has one, I too would love to hear it.) See ya, – Ron P.S. I just copied a portion of the above to Jonas, on the wishlist forum, to make sure.<g>
#188105From: REZA DASTMALCHIANAug 30, 1995 12:51 PM
Ron: Thanks for your reply. Yes, I do need to move around the 3D object and I cannot not fake it. This is for a feathered glow effect simulating the Earth's atmosphere and I'm having a very hard time doing it. It's good that you relayed this to Jonas and perhaps it should also go to Gary Yost as well. I wish they would concentrate on adding these essential features rather than trying to get on the uncertain NT bandwagon. If you think you have a solution for my glow effect please let me know and I will gladly pay for your time. -Reza
#188119From: MARTIN G FOSTERAug 30, 1995 1:22 PM
Reza, >> This is for a feathered glow effect simulating the Earth's atmosphere and I'm having a very hard time doing it. << aurora mapping by Video International and sold by Digimation could do the trick for you. Or you might try a sphere with transparency falloff. You may have to render twice: once with the atmosphere and then the earth composited on top. Martin
#188280From: LEE STEELAug 31, 1995 7:59 AM
Aurora Mapping isn't available yet, but you are right, this would do the trick.
#188315From: MARTIN G FOSTERAug 31, 1995 10:41 AM
Lee, >> Aurora Mapping isn't available yet << any word on availibility? TIA.
#188498From: LEE STEELSep 1, 1995 7:39 AM
You might want to send some mail to Aleksey. We wanted to finish Refraction Mapping first before moving on to Aurora Mapping. Should be very soon.
#188211From: David J. MarksAug 30, 1995 8:05 PM
>> This is for a feathered glow effect simulating the Earth's atmosphere and I'm having a very hard time doing it. << I've been successful using transparency fall-off on a sphere for this effect. Try setting New-Subtractive-Transparency=OFF in the 3DS.SET file for the fullest transparency. >> uncertain NT bandwagon. << I think you may be mistaken here. NT seems to be a solid operating system, complete with multi-tasking, multi-threading, long filenames, networking, etc. – Dave
#188333From: REZA DASTMALCHIANAug 31, 1995 1:30 PM
Dave: Trancparency falloff for a sphere certainly is the most realistic atmospheric effect except for two big problems. 1) Hard outer edge which requires 2-pass rendering and bluring. This has its own problem since bluring should increase as you get closer to your planet. 2) Too much opacity midway between the outer edge to where it fallsoff to totally tranparent. But still this technique is more realistic that the 2D gradiant disk. If you know of any tricks to deal with the above 2 issues i'll appreciate a hint. Sincerely, -Reza
#188230From: Ronald K. LussierAug 30, 1995 9:28 PM
Reza, I have used something else for planets actually. A flat ring around the planet (that has to be animated to always face the camera) can be mapped with a very nice falloff of your choice. Even a nice color transition in the atmosphere. It does take some tweeking though. Also, multiple spheres can help, and increase render time. – Ron
#188258From: REZA DASTMALCHIANAug 31, 1995 2:52 AM
Thank you Ron, I'll give it a try.
#188602From: Tim Krego, [pro.image]Sep 1, 1995 1:58 PM
>I wish they would concentrate on adding these essential features…< Who determines what is essential? There is a wishlist section. >…rather than trying to get on the uncertain NT bandwagon.< There is nothing uncertain about the NT bandwagon. Many DOS, Novell, Mac, and unix guys are going to NT. If I used any OS besides NT or unix I would be feeling some uncertainty at this point. Give NT a try.
#188085From: CSA/CAAug 30, 1995 11:45 AM
Reza, Try creating an opacity map. This lets you specify where (and how much) transparent. Kevin Krell – Computer Support Associates
#188106From: REZA DASTMALCHIANAug 30, 1995 12:54 PM
Kevin: I need to map this tranparent material onto a sphere and move around the object so it cannot be faked. Basically, I need to make a feathered glow effect around a ball that rapidly fades to transparent towrds inside. Any ideas? -Reza
#188182From: CSA/CAAug 30, 1995 6:17 PM
Reza, Opacity map on the material should still work for fly-arounds. Have you tried it? Kevin Krell – Computer Support Associates