Handles for motion paths?

[fordmar]

I want to make a motion path to form a smooth curve, and found a method that sorta works: Select one parameter of a keyframe (such as the X position) and in the keyframe attributes, click off "Auto Tangent." Handles then appear that will bend the path like a spline. Magical! Only it doesn't work every time or for every keyframe

In the attached sample project, I set up two objects - one has handles, the other doesn't. As far as I can tell, I'm following the exact same procedure on each, but for some reason I was only able to create handles once. Toggling auto tangents on and off doesn't seem to do anything either.

This smacks me as a classic missing tick box - somewhere along the line I'm missing a critical parameter setting.

I'm a little unnerved by the inconsistency - I'm about to launch a big project which will require this kind of control throughout and if it starts glitching out halfway through, I'll be stuck.

My fallback is align to spline, but modifying the keyframes directly seems a simpler approach - if I can get it to work.

Thanks
Motion Path Handles.c4d

[Dr. Sassi]

Hi fordmar,

Thanks for the file.

As far as I can see, each path is set up by a different Attribute Manager> Tangent Preset.
If that is set, for example, to Auto Tangent, then you get no handles.

https://help.maxon.net/c4d/2024/en-us/Default.htm#html/CKVALUE-ID_VKEY_PROPERTIES.html#ID_CKEY_PRESET

While in the timeline, you can select a keyframe and use the T~1 to T~9, and I or O, shortcuts, see image.

Instead of "Align to Spline," explore the "Spline to Position Track" as an alternative, which works in both ways: "Position Track to Spline."
https://help.maxon.net/c4d/2024/en-us/Default.htm#html/10622.html#PLUGIN_CMD_465001063

My best wishes

[fordmar]

I guess I'm not getting it. I have seen tutorials where the motion path can be manipulated in the viewport with handles like a spline. In my case, I can get handles on one keyframe but not on the other, even though they tangent settings are the same.

I may be overthinking it - the requirement is a smooth curve, and I can manipulate the keyframes in the timeline well enough to get what I need. It just seems more direct to be able to do it in the viewport.

[Dr. Sassi]

Hi fordmar,

Please have a look at the file below, based on the file you shared:

CV4_2024_drs_24_ANph_01.c4d

There are no handles when the Auto options are on, and if the Tangents are set to zero, there are also no handles.

All the best