CompuServe Thread

#Globe Animation Help!

8 messages in this thread
#12669From: KEITH TROMERApr 15, 1992 6:41 PM
list I have been told to send this message to Gary Yost. If this is reading it please feel free to answer in addition to making sure that Gary sees it. I have been asked to do an animation of a rotating globe with "communication lines coming out of the US and wrapping around the globe to many other countries at once (at the same time the globe is rotatin). I see a number of possible ways to do this, in addition to a number of problems with each one. The first thing I thought to do was to make a small cylinder with many segments. Create a number of copies of the cylinders (scaling and bending) to wrap around the globe. Then Morphing. However, The bend feature does not respond with enough accuracy. (i.e. the cylinder could not "hover" close to the globe. When it is small ( the second or third step) it comes out to far before it bends, and the angle i severe to appear to be a small part of a long line. The second Idea was "Dup Links" – But I soon found out that I could not cre new links in the middle of the animation. Finally, I created a circle in Shaper and lofted on a semi-circle path. I positioned the shape in the middle of the globe, linked it to the spinning globe and rotated it so that it appeared to be "growing" out of the globe. I have several problems with this method: First, as it rotates the point the "line" intersects with the globe changes. I was able to fix this by more accurately placing my pivot point. But this is extremely difficult with many lines going in many different directions. My second problem is that it is virtually impossible to get the "line" to land (end) at the appropriate place (country). And so I am asking what you think of the different problems I am having. What solutions, if any, do you have? Is there any methods I am overlooking? A prompt response would help me immensly. Thanks for your time. Sincerely, Keiht Tromer ^th 70711,3217 Oh yeh, One more thought! — What about a flic for a surface material?
#12676From: Yost GroupApr 15, 1992 7:18 PM
There is a dead-easy way to do this with 3DSr2 (and lots of more complex ways to do it in r1). It's a modification of your third method, based on lofter paths with circles being extruded along them. Instead of moving the objects, create the lofted "communication lines" with the new Mapping Coordinates button ON. When asked for repeats, select 1 repeat along the length. This will make the "U" mapping value along the length go from 0 to 1. Then, use an animated opacity map (made in AA or AA Pro) that is simple a black background with a white line growing from left to right, with one pixel per frame of final animation. This flic only has to be one pixel high, and as many pixels wide as you've got total frames of animation. When the animated opacity map is applied to the "communication lines," the lines will appear to grow from one end to the other. This is the same technique that I recently described on the forum for someone who wanted to make text "draw itself". – G
#12735From: doug wolfgramApr 16, 1992 10:34 AM
..nnd the same solution we used for growing comm lines for the movie "Sneakers". But Brett thought it up all by his lonesome, even after all the Yost bugging I did… (grin)
#12797From: Yost GroupApr 16, 1992 10:57 PM
Brett is a genius, that's why! <g> Seriously, I noticed that the picture of his in the Computer Graphics World announcement about 3D Studio didn't credit him. I was seriously bummed about that, and you ought to bother whomever is responsible for the lack of byline. – G
#12836From: KEITH TROMERApr 17, 1992 9:23 AM
To all that replied: I thank everyone for their help. I am in the process of doing this animation. I think the way to go is to create my "lines" and apply a "FLI" Opacity map. the flic is a wipe from a white screen to a black screen. This seems like the best (fastest) way to do this. However, I am very unhappy because I cannot have my "lines" cast shadows. Or can I? As far as I can tell an Opacity mapped object casts a shadow for the entire object, rather than just the opaque section. I am still having great difficulty placing the lines. It seems to be a trial and error process that is very slow on my 386/25. if anyone knows of a shortcut, please reply. thanks again everyone, Keith
#12679From: CSA/CAApr 15, 1992 7:41 PM
Keith, Here's a few thoughts: Could you create your connecting "cylinder" and link to a dummy that moves with the globe? Just get the shape right to go from origin point to destination. Then apply an opacity map (from fully transparent across to fully opaque) to make the connecting line "grow". Kevin Krell – Computer Support Associates
#12685From: MARTIN G FOSTERApr 15, 1992 8:24 PM
I like the animated texture map idea. If you are already using a texture map for the globe, you could draw all your lines on frame 1 in ani pro over the globe map, then insert a frame and remove a bit of the lines, insert a frame remove a bit more etc. until on your last frame all the lines have gone. You could get fancy and create a "drop-shadow's" for your communication lines to add some realism. If you want your lines away from the surface of the globe (3d effect) you could make another version of the flic with white lines on a black background and map this to a sphere a little bigger than your original globe and use this as an animated opacity map and the original with full colour version as the texture map. The maps would probably need to be 2-sided also. Sounds like you have a few ideas to try out. Let us know which you settle on.
#12739From: Yost GroupApr 16, 1992 11:06 AM
The animated map is probably the best solution, but this reminds me of an obscure technique that could also be used whenever you need line geometry. If you wanted to animate circular lines, you can create a cylinder and apply a wireframe material (possibly self-illuminating). The trick is that you can determine which edges of a wireframe object will render by turning them on and off with Modify/Edge/Visible and Modify/Edge/Invisible. This might not work for your current animation, but keep it in mind whenever you want animated lines. You can create interesting wireframe objects by simply selecting the edges you want rendered. – Jack