Animate and roll a ball the correct way in blender.

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[@frenkyb123]

Thanks. Very very good explanation.

[@knottt]

This is the best way I could found, solved a big problem for me! Thank you sooooo much!

[@Coastfog]

I found this driver earlier but just couldn't make it work. It was a tiny but essential bit I missed, and you led me in the right direction. Have my gratitude & my sub!

[@robinsquares]

-2*curve_length/diameter*(eval_time/eval_max)

[@abhicool153]

thank you so much

[@RobertShane]

Your expression can be simplified. You're basically doing 2 / diameter but since diameter = 2 * radius the twos can cancel out. The simplified expression is -curve_length / radius * (eval_time / eval_max).

[@lekkerfruit2208]

what is the radius. I got the error F-Curve with path 'eval_time[0]' cannot be keyframed, ensure that it is not locked or sampled, and try removing F-Modifiers.

[@hanneshuber3d]

Thank you so much!! Just discovered your channel, awesome quality content! Love it

[@GlimZee]

Good Teaching and Good Explanation every Details

[@daniel_a.m.]

thanks man!

[@dileeshaabilash5562]

thanks bro best tut ever

[@themoonman8953]

Very nice Video. Thank you 🙏

[@tongenproduction3646]

Thanks for good lesson I got learned something

[@Honey_Tabby]

For anyone trying to use a path and the calculate length isnt working go into edit mode, right click path and select set spline type to bezier, you may need to subdivide it.

[@sandan3]

thank you!!

[@SourceAwareness]

THANKS, Great Tutorial, my Brother, and cute cats you have there. 🙏🏾

[@sarahashemi6521]

Thank you very much for this nice tutorial. I also like your cat ❤

[@sebastianb3345]

Thx.

[@starsky29200]

merci pour ce tuto. ça fonctionne bien ;)

[@sewwandisenevirathna9508]

Thank you very much. This helped me a lot in my university assignment. Although the accent was a bit hard to comprehend at times, it was clear and easy to follow. P.S. that cat behind you is absolutely adorable

[@3Dschool-David]

I didn't know my accent was that thick hahaha!

[@emanak2810]

I have found that a division of 25 as the eval_max makes the ball roll smoother on blender 4.0

[@rypiyx]

bigger balls , 'YEAHYEAH haha

[@Najim_R]

This was exactly what I needed! Thanks!
One question, afther you did all that can I still edit the curve at the end , like make it longer.. or do I need to update the curve length in the code again ?

[@3Dschool-David]

Yeah, just update the curve length and you are set.

[@plcreator483]

I can't even find the Edit button at 7:43 on my blender

[@user-bq7mm9nh7g]

How it works with circle curve?

[@lekkerfruit2208]

F-Curve with path 'eval_time[0]' cannot be keyframed, ensure that it is not locked or sampled, and try removing F-Modifiers."
help!

[@lovelylonerboy7156]

Can you make the curves anything

[@aliensoup2420]

Well presented, but of course, there is no subjectively "correct" way to roll a ball - the correct way is whatever works for your intended animation. But if you want to be anal about it, this is not the physically correct way to animate a rolling ball in any direction, because a ball does not steer itself around a path. There is no forward direction or orientation for a ball, it just changes its apparent rotation axis depending on the forces placed upon it, which is impossible to do in animation without using quaternions (or a physical simulation, which uses quaternions). I am surprised to see a "Curve Length" utility finally made its way into the interface. That is quite helpful.

[@cgmoe8441]

can i use this for a circle path?

[@aliensoup2420]

Yes a circle path will work.

[@Krzyh4]

When I click button to calculate curve lenght nothing changes :( If I make a new curve it can calculate it, but if I convert mesh to curve it cant. Any solutions? :(

[@natasha4695]

how did you get to the formula? Where does -2 come from? Halp!

[@natasha4695]

I managed to get it to work, but would still give you a cookie if you tell me about -2

[@RobertShane]

@@natasha4695 The 2 comes from the fact that he didn't simplify the expression. He's doing 2 / (radius * 2) which simplifies to 1/radius. The negative comes from him using a positive 100 at the end instead of a negative.

[@vyskochill487]

why my ball is bouncing instead of peacefully rolling?

[@juankarlomorales4523]

can't follow I'm distracted by the cute cat in the back

[@maymae2884]

Thanks a lot I was able to make my music video with this video!! th-cam.com/video/WsPf2hbKNpc/w-d-xo.html