# Unanswered forum question from 2014

This is the exact same question I have. I hope it isn’t impossible.

The most elaborate answer was kind of silly, even thoughtless in a way… If someone doesn’t know (yet) know how to ROTATE AN OBJECT ALONG A SPLINE: They PROBABLY WON’T UNDERSTAND THIS:

*“You need to match the vector, so if your particle effect has for example y forward, break the rotation along spline into the 3 floats and them make a rotation but swap the vectors into the correct order for you.”

oh, Come on man!!!

The guy never said he succeeded, (he probably gave up) After reading the entire thing I too come away, knowing no more about how to do this: ROTATE AN OBJECT as it travels along a spline.

There is obviously some Rotator Multiplier or something that will do this, How about an answer for posterity and pride? (plus it would help me today!)

THANK YOU.

I may as well add my BP as it is:

The problem with doing this is that you will get random flipping, if your spline’s up vector is +z and your spline goes straight up, it will not know how you want it to rotate. It is similar to gimbal lock when using euler rotations. If you can set it manually, you can get the splines forward vector and base rotations of the change in that with respect to the world or the object. The only other way I know of is to fake an offset to get a consistent up or right vector, or to use a technique called Rotation Minimizing Frames.

There is an asset on the marketplace that uses the offset method to correct spline twisting: Spline Twist Correct

A Primer on Bézier Curves - This is a good link for the actual math behind bezier curves (same as a spline segment) and it shows how to use the Rotation Minimizing Frames method, but that cannot be done in one frame since it needs to be reevaluated.

Hi, thanks,. I don’t want the spline to rotate, I have no problem with the spline.
I just want the Object on the spline, to Start in the ‘correct’ orientation. (the way it does in most other other software. ) I have control over every [art of the objects travel along the spline, except the very first frame, (If you tell an object to move along a spline, software like 3ds max, etc. usually starts the object at Vertex 1 right side up ready to travel,. Only usually flipping the object while in travel due to purposeful twisting/curving in the spline or extreme banking,…)

First post? I have been here for years. Years of built up frustration… Really? Not even a tad of a smidge of embarassment that your ‘community’ could just leave a simple question from 2014 with nary a guess, much less an answer?

Considering what I am pointing to, that is a pretty short ‘tirade’. Tirade light? I am compelled to say it as I see it, as any ARTIST should. I hope I wake ONE PERSON up to the petty. If the cost of being direct and honest is: ‘Even LESS Help’, I’m sure I won’t mind or even notice, I have gotten much less help here than I have given. However I remain hopeful there are a few who appreciate honesty and knowing where a person stands rather than always and only get fake polite garbage.
Not surprisingly, I sense very few fellow Artist’ here, I’ve seen the same 3 games get made over and over for 25 years. WELL THIS IS WHY. The bitter irony of people wiling to waste time giving unsolicited, unwanted and unnecessary ‘advice’, while leaving endless questions UNTOUCHED for YEARS… Perhaps you could find a better use for your time than worrying about my way of righting wrongs, or telling me how and who to be. Maybe go answer some old questions! ;~) All answers help somebody…

I was not referring to the spline.