Rotation around a point

Hi there

I'm working on an animation for a friend and it's about to drive me nuts

I've got the avatar in a pose for sliding down a pole (like a fireman) and it works fine as a stationary pose. So what I try to do next is have the avatar rotate around a point where the pole will be. This works fine in Poser rotates around the offset center point. But when I bring the BVH file into Second Life the Vertical axis shifts back to be inline with it's hips. So it looks like she is spinning on a stick that has been shoved up her bum.

I guess My question is is this possible to do in as an animation? and if so what am I doing wrong. Or since this pose goes on an elevator script to move from floor to floor, am I better off also dropping a rotate script into the sitting prim and using that to handle the rotate. I just want a 360 ish spin as they come down the pole.

Thanks so much for any help

Oh yeah using Poser 5.04 for the Mac exported to bvh for upload

It seems to me you'd almost be better off making a static pose, and having the prim handle both the rotation and the dropping down - you can make the animation appear to slide down, but remember as soon as you unsit you're going to end up right back at the top of the pole where you started, since animations don't *really* change the position of the avatar.

If you end up wanting to do an offset spin though, you'll probably need to do some math and offset the hips manually for each keyframe. I think if you break out a calculator you'll find for some rotation in degrees R the hips need to be offset sin(R) on one axis, and cos(R) on the other axis. If that doesn't make sense let me know and I'll explain better in the morning, right now it's late and I'm feeling lazy

You have to rotate the hip joint in Poser and you will need to do it in 3 dimensions and also move your figure left-right, back-forward, up-down to place it in the correct position to the pole. I don't think you will necesarily need to stop frame animate this, but I would expect to need a key frame for every 0.25 seconds of animation. Assuming the hands stay on the pole and the arms don't do anything fancy, it shouldn't be too much of a problem.

Thanks Anti and Deira

I was afraid advanced math would be involved

In poser I had moved center of the hip rotation axis and placed it at 0/x/0 (the same height as the hip when the figure is standing)so that way when I twisted the hips I rotated around the poles y axis and made keyframes every 5 frames with a 45 degrees change each key. Which worked in poser but not SL

Before that I did basically the same but instead of offsetting the hip axis I made a ball at the center of the pole and set it as parent and then did the rotation and keyframes again with the same results but that is where I figures that the rotation script would work as a patch if I couldn't get this to work.

So I guess I'm at a loss when you take of moving the hips in 3 dimensions because I thought that's What I was doing. so if either of you could expand that I'd be greatly appreciative

Thanks

Hi Lyndzay - I'm a bit confused now because I don't understand why this has not worked for you. By rotation in 3 dimensions - I meant you have to have the HIP selected and use all 3 rotation wheels as necessary - the roll left-right and the pitch up-down as well as the spin round in the vertical axis. With hip selected, you will also need to use the x, y and z translate wheels to move your figure to left-right, back -forwards and up-down to go round and down the pole. You can't achieve this in SL by moving the body, even though this works fine in Poser and is much easier than rotating by the hip.

If you have done all that I don't see why the bvh upload isn't seeing the rotation (or at least some of it, as there is a limit to the degrees of rotation SL will recognise.)

I guess you have checked carefully that Frame 1 is the T-pose with zero rotation on all joints and that Frame 2 has moved the HIP rotation parameters by a degree or two?

I can only suggest you check your Poser file, re-save it and export again to bvh, just in case something went awry, and try and upload again. You could also try re-importing your bvh file into Poser and seeing if that shows any differences - apologies if you tried all of this already.

If you still have a problem, feel free to IM me in world and you can email me the bvh and I will take a look at it for you.

Maybe you answered your own question? As you found, SL doesn't see any "offset center point", just hip rotation and movement, so if you remove your offset, you'll see the same thing in Poser I presume?

Either way, wouldn't it be much easier to do this with scripts/prims? Rather than trying to move/position/rotate the pose to enough positions on a circle to appear to rotate around a fixed spot? There also wouldn't be any lag of an animation being sent to the client.

Okies, I take that back, it only took a minute or two to create this in QAvimator, and it came out round enough with keys every 4th frame or so (and no advanced math, LOL)

I just moved the hips back (negative) on the 2nd frame, made the same key on the 30th frame but rotated 360 so it would loop. This provides the rotations for all the other keys too. On frame 16 I moved the hips to the opposite (positive) side. Frames 9 and 23 were moved the same amount to the sides (one positive and one negative). Then I made a circle prop and visually made keys in between on 6, 13, 20 and 27 with the hips moved to line up with the circle instead of mathematically!

My distance moved on the aligned axis was 50 (frames 2, 9, 16 and 23) while my in between frames ended up at 34 and 34 (positives and negatives respectively of course), my reference circle prop was about 100 diameter obviously.

Although it showed in SL fine, wouldn't it still be better to make this with a script and prims, since you'll need those for the vertical movement anyway? So that way it would always by in sync too, rather than the animation playing after they've moved, or looking different the first time from the next after the animation gets cached? (Or worse on a packet loss day, not rotating at all?)