CompuServe Thread

#double reflections

7 messages in this thread
#33464From: Rich SchwartzJan 26, 1993 3:49 PM
Another question… I need to render a scene that has two flat mirrors in it, with the reflection of one mirror showing in the other. So far, I have ony gotten a black field where the reflection of the first mirror is supposed to appear in teh second mirror. I assume there is no ray tracing in 3DS, and my best bet is to render teh scene in teh fist mirror, use ANI to make a *.CEL, and apply this as a bitmap to the first mirror, then render the scene looking at the second mirror. This will be a pain. Is there a better way? From bounce shot blues… Rich Schwartz NASA Langley Research Center
#33486From: Larry MintonJan 26, 1993 6:51 PM
On the distribution disk there is a readme file. In the readme file it describes a parameter in the 3ds.set file called (something like) AUTOREFLECT_LEVELS. Default setting is 1. Bounce that up. I think that parameter handles flat mirrors, but I'm not positive. I'm sure Gary will let us know if it doesn't…. LAM
#33529From: Yost GroupJan 26, 1993 11:36 PM
Check out msg. 33528. <g> – G
#33554From: Larry MintonJan 27, 1993 9:37 AM
To paraphrase Angelo, "I do CIS from work and thus was relying on memory (bad move usually)." To save face, I actually looked it up at home, and sent a retraction. Guess I'll just go back to asking the questions… When I skew selected vertices, what the heck is the offset number displayed at the top of the screen mean? Is there any deep philosophical reason why none of the "snaps" work when skewing? A skewed mind wants to know. I'm pretty sure I've already asked for the following to be put on some wish list: For those commands that work off of the global axis (such as skew), have them work off of the construction axis if it is defined. No fun selecting all and moving everything to get the vertex to skew from at 0,0. (As you might be able to tell, I've been mitering corners lately). LAM
#33571From: Yost GroupJan 27, 1993 1:26 PM
The "offset" display when skewing is the world unit offset of the base of the skew operation. Regarding the skew axis… do you know that skew is sensitive to the state of the local axis icon? When it's on, skewing happens around the center of the selected vertices, and when it's off, it happens around the center of the world. – G
#33528From: Yost GroupJan 26, 1993 11:35 PM
Actually (contrary to what LarryM mentioned, the 3DS.SET parameter to handle inter-object reflection is ONLY for cubic environment maps, and it's called NONFLAT-AUTOREFLECT-LEVELS for a reason… it doesn't affect flat mirror reflections. As it says on page 39 of the Installation Guide… "Note: Interobject reflections are not allowed in flat reflection maps." Your technique for faking the second reflection sounds like it's worth a shot. Good luck! – G
#33552From: Larry MintonJan 27, 1993 9:07 AM
Ignore my previous message. The name of the parameter is "NONFLAT-AUTOREFLECTLEVELS". Sort of by definition it doesn't do what you want. Oh well… With the method you mentioned, you can map a TGA to an object, so you won't need to go to ANI to make it a CEL. The problem will be to get the right angle on the camera used to make the TGA to map to the mirror. Have to angle that camera off the mirror object normal the same number of degrees as your "real" camera is, but mirrored. <did that make sense?> -LAM