CompuServe Thread

#Add Key?

6 messages in this thread
#144527From: Jerry C. BensonJan 1, 1995 9:03 PM
I'm confused as to the "add key" in the Keyframer using the "Key Info" key. Let's assume you have a 150 frame animation. At frame 150 you rotate an object 3 turns. Then go to "Key Info" and add a key at frame 100. The book seems to indicate that this will "… have no effect on the animation…" But when you check it out there is no rotation untill frame 100 and only 1 turn from 100 untill 150. The frame at 150 now says only 360 degrees rotation (1 turn). Who changed it? "Inside 3D Studio" seems to indicate the same thing. P. 768… "using the Add button does not adjust anything at that particular frame, instead it records and "locks in" the current animation effect at that frame." Obviously, I've missed something. It seems to me that there should still be 2 complete rotations at 100 when you "add a key." Where have I gone wrong. Thanks a byte. Jerry
#144548From: Mike MorganJan 1, 1995 11:38 PM
>>I'm confused as to the "add key" in the Keyframer using the "Key Info" key.<< I think the confusion here is that you are trying to add a rotation key, if you do not want to add any movement to the animation you need to add a position key. I ran into this problem way back when I was doing allot of manipulation of rotation keys for a animation. The problem you are running into is that 3DS defaults to the last change you did in the Keyframer, which was a rotation of frame 1080!! If you want to have 3 turns from frame 100 to frame 150 just copy your objects first frame to frame 100 and then do your rotation at frame 150 and you will have it. Good Luck and Happy NEW YEAR. Mike Morgan, CAD Forms Inc.
#144970From: Jerry C. BensonJan 4, 1995 12:06 PM
Mike: Thanks for the help. I thought that if I'd added a key at frame 100 that at that point the object had turned 2 turns. Therefore I could delete the rotation key at 150 and be left with 2 turns at 100, but not so… Anyway, as I better understand the whole process it will make animations much easier in the future thanks to help from my fellow users. <g> Hope to see ya on the C-serve again. Jerry
#145003From: Mike MorganJan 4, 1995 2:59 PM
>>Hope to see ya on the C-serve again.<< If this is the Jerry from San Diego, I will see you at the 3DS Multimedia Users Group on Thursday. Glad to see that things worked out for you. Mike Morgan, CAD Forms Inc.
#144897From: Steven ElliottJan 4, 1995 12:29 AM
Hi Jerry, I'm a little rusty on the details but what you've encountered is a special case of how 3D Studio handles rotation in the Keyframer. If I remember correctly, rotations of greater than 360 degrees get reduced get reduced when subdivided with new keys, into separate rotations between 0-360 each. In other words, when you inserted that key at frame 100 3DS compared the angular rotatio between frame 0 and frame 100 and set the key appropriately. Now you know that the object rotated 720 degrees between frame 0 and frame 100 because you defined the process, but 3D Studio can only look at the position of the object at the two key frames. Take a box and place it on a table. Mark its corners and then pick it up, rotate it 720 degrees, and place it back on the table. Looking only at its start position and its end position, what is the angular difference between the two positions? It's 0 degrees. 3DS faces the same dilema when you add keys between rotation greater than 360 degrees. The solution is to plan ahead when keyframing to avoid the need to subdivide rotations greater than 360 degrees. I pretty sure that's how it works. If I missed something or totally dis-remembered the whole thing, I'm sure somone will correct me. Steven
#144971From: Jerry C. BensonJan 4, 1995 12:11 PM
Steven: What a great explanation! Somehow I always want to know why and it sticks in my mind better if I know the details instead of just doing a work around. You've been more than helpful and I'll try to "stump the pro's" again soon. <G> Happy New Year! Jerry