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View Full Version : Setting ease in/out without changing motion path shape.



Mark Borok
01-22-2006, 01:46 PM
I'm sure I was just reading about this somewhere, but I can't remember where. The thing I want to do is animate a camera moving in a straight line, coming to a stop, then moving in a different direction in a straight line. If I set the interpolation to linear in the motion graph I won't have any acceleration/deceleration. If I set the interpolation to TCB or another curve, I can make the camera accelerate and decelerate, but at the same time my motion path will change into a curved path instead of an angled one.

I know I can select "show speed" and "show velocity", but it doesn't look like these lines can be edited independently of the motion path.

Edit: Never mind, figured it out. Change continuity.

Mark Borok
01-29-2006, 07:27 AM
Okay, even though I figured it out, it still sucks. I feel like with the TCB splines I have almost no control over the motion path. I tried the bezier curves, but those don't work that well either. Is there any kind of plug-in or other means of manipulating an object along a motion path without the headaches?

Also, I made a rail extruded object (a hose) and surfaced it, and now I realize that its diameter is too large. I want to make it thinner, but I see no way of doing that except by deleting the object and re-extruding it with a smaller circle for a profile. Just about every other 3D program I've encountered allows you to edit the profile of an object after you have extruded or lathed it.

I am sorely tempted to downgrade to Carrara. I started doing 3D in RayDream and then decided to upgrade to Lightwave as a more professional program, and now I find myself agonizing over things that would be non-issues in a low-end app like Carrara.

Snosrap
01-29-2006, 12:38 PM
Also, I made a rail extruded object (a hose) and surfaced it, and now I realize that its diameter is too large. I want to make it thinner, but I see no way of doing that except by deleting the object and re-extruding it with a smaller circle for a profile. Just about every other 3D program I've encountered allows you to edit the profile of an object after you have extruded or lathed it.

I am sorely tempted to downgrade to Carrara. I started doing 3D in RayDream and then decided to upgrade to Lightwave as a more professional program, and now I find myself agonizing over things that would be non-issues in a low-end app like Carrara.


The tool you want to use is called "Point Normal Move". I use it all the time for sizing rail extruded geometry. Works great! Hang in there, LW hasn't let me down yet and with 9 on the horizon things should only get better.

Cheers Snos

Mark Borok
01-29-2006, 01:51 PM
Thanks. Too many tools to keep track of.

Still might get Carrara just for the ease of use, but I sure don't want to let all the time and money invested in LW go to waste.

Snosrap
01-29-2006, 03:04 PM
Thanks. Too many tools to keep track of.

Still might get Carrara just for the ease of use, but I sure don't want to let all the time and money invested in LW go to waste.


Don't mean to be rude or anything, but you just stated that there were too many tools to keep track of, but you want to buy more? LW is the fourth 3D package that I've learned over the last dozen years, and just the thought of going through that is enough to make me delve into LW more and more to wring out every last ounce of it. Not there yet!

Cheers

SplineGod
01-29-2006, 06:05 PM
Mark,
Create the ending keyframe for your camera so the motion path is in a straight line.
In the graph editor select all the end keys for the translation channels and change the curve to bezier.
Use the alt + LMB to grab the bezier handle on each channel and adjust them so that each handle is horizontal and the control points for those handles are lined up vertically.
Now you can adjust each control handle horizontally while still keeping each control point lined up vertically. This will allow you to adjust the ease in of the camera but still keep its motion path straight.
I think your money would be best spent on just taking the time to learn LW a little better. Theres always ways to get things done with a little more investment of time rather then money on something else. I would imagine you went with LW because Carrera had some deficiencies. Keep poking around some more :)

Also a nice thing about point normal move is that you can select parts of your extruded tube and scale them in and out.

Mark Borok
02-04-2006, 01:50 PM
I'm sorry, I must either be following your advice wrong, or else we're speaking about different things.

I drag the camera some distance along the Z and Y axes. I change the end points to bezier in the graph editor. This results in two diagonal straight lines in the graph editor, and the bezier handles are lined up along those straight lines. If I move the bezier handles to a horizontal position they become tangential to the diagonal lines and cause the lines to become curved (as one would expect) which also causes the motion path to become curved. If I drag the bezier handles so that they become shorter or longer, but remain aligned to the lines they control, absolutely nothing changes. The frame ticks on the motion path in the main window do not move closer together or farther apart as I move the bezier handle in or out.

So far the only way I've found to adjust the ease-in/ease-out and the shape of the motion path independently of each other is by changing the values of the tension and continuity in the TCB splines, and even that is unpredictable. It doesn't help that LW regularly crashes when I'm doing anything in the graph editor.

SplineGod
02-04-2006, 05:56 PM
The motion path should not curve if both curves in the graph are changed proportionally. In other words IF the rate of deceleration for both channels is the same then the motion PATH shouldnt change.
I havent had any problems with the graph editor crashing either. You might try starting off with new configs. Also, try posting up the motion path here. :)

Mark Borok
02-04-2006, 08:37 PM
Okay, I got it finally. Still a very clumsy way to work. When your keyframe is at a midpoint on a curve in the motion path, it looks like you have to keep dragging the bezier handles up and down in the graph editor until you get it right. It doesn't have to be this complicated.

As for the crash, it may be a Mac issue, or it may be what you said about the configs.

SplineGod
02-05-2006, 02:51 AM
I agree, shouldnt be that complicated but it works :)
In earlier versions of LW I believe you could edit the velocity curves and do stuff like rotate motion paths on any keyframe. Dont know why that stuff was removed.

Mark Borok
02-05-2006, 06:56 AM
That's bizarre.

Thanks for your help.

toonafish
02-05-2006, 08:49 AM
Use the alt + LMB to grab the bezier handle on each channel and adjust them so that each handle is horizontal and the control points for those handles are lined up vertically.
Now you can adjust each control handle horizontally while still keeping each control point lined up vertically. This will allow you to adjust the ease in of the camera but still keep its motion path straight..

Hmmm, that's weird. That sounded new to me so I just tried it but it doesn't work. I can make the bezier handles as long as I want but the velocity doesn't change a bit, just the shape of the path changes.

The only way I know to change the velocity of the incoming curve is with TCB and Continuity and Bias.

I've never been able to change the velocity with beziers without changing the shape of the motion, that's one of the reasons I hardly ever use them.

edit: maybe it works for you because you only translated the object in one channel like the X axis. Try it with a motion where you move the object in all 3 axis and you'll see what I mean ;-)