how do i reverse a circular movement?

the trains wheels go backwards!
here is the blend file
thanks

PS then I need to make it go from left to right with the wheels staying with it! Parenting?

Attachments

oldtrain2cycle.blend (1.04 MB)

I see your using the Wheel object as the base object to drive the bones with…

but the Wheel object in Object mode needs to have it’s Rotations “Applied” in order for all the Rotations in it’s Rotation Matrix to be read properly by the other bones (or objects) that the Wheel is Driving…

one would think it would not make any difference… but it most certainly does…

so select your Wheel object and hit “Ctrl+A” then “Rotation and Scale”…

you will have to readjust your bones to fit on the wheel … but everything should work from there…

That is the first Major problem… there are others… I will have to work out to fix them…

but I think if you fix that the rest of it will work even if you have to ReRigg…

taking a second look… I think you have the Rigging and Armature paradigm backwards a little bit…
perhaps I’m just not understanding your approach here…

but normally… you parent your objects to the Armature… not the Armature to the objects…

Again I suppose there can be some instances where you would not want to do that…
but in this instance I don’t think that’s what you want…

that is you want the Wheel to be parented to the Crank bone and not the Crank bone parented to the Wheel…
then you animate the Crank bone… and it drives everything else…

IMHO…

also… I appears that none of your objects have there Rotation and Scale applied…

remember Ctrl+A then “Rotation and Scale”…

to on the Right hand tool bar in the 3D window under “Transform” you want Rotation to read all Zeros… and Scale to Read all Ones…
Before… you start animating anything…

if you don’t… all your animations will go wacky…

Remember blender is designed that you need to modify objects in edit mode…
when you do that you never have to apply Rotation and Scale…

But it’s always a good practice to move into edit mode and do a Ctrl+A > Rot & Scl…
anyways just to be safe…

… Also you need to set the chain length on your IK constraint to 3, so it only goes back to the “stroke” bone or you will get problems if you add another IK chain - like the other side for instance.

When it comes to moving the train alone the track and turning the wheels at the same time, you will need a Driver on the rotation based upon the distance the wheel travels. I can help once you get that far, just let me know - remember all rotations in Drivers are in Radians not Degrees and there are 2 * pi radians in a full circle of 360 degrees, I can also help with the maths!

I too have had a quick look at your file and apart from the points made by Novman, you have the red wheels spread across all layers, I don’t think you want this, so select them and key M and select just one layer.

The best way to rotate an object many times is to use a Driver based upon perhaps the frame rate, so your scripted expression might be something like (frame / 50) * pi - this will rotate the object one turn for every 100 frames. Trying to keyframe large rotations often results in the object snapping back the wrong way - I have noticed that your animation does not run smoothly and this will correct that. Don’t be fooled into thinking that your wheel is going the wrong way when it may be due to the “frame motion effect” - this you can see in videos where wheels appear to go backwards or stop depending on the speed of the vehicle relative to the camera frame rate. To check the rotation, just select one or two outer faces and change the colour of them (by adding a new material and assigning some faces to the new material, in Edit Mode) Then when you run your animation, you can see which way they are running. Your large wheel is in fact turning in the correct direction, I checked it…

I agree with everything that Novman has said - put these right first then move to the next phase.

Cheers, Clock.

PS. Scripted Expression will only work if you check the “Auto-run Python Scripts” in User Pref > File Tab

Thanks guys
and all I knew was that the wheels went backwards!

I deleted the movement and put it in again. works fine.
and removed it from all those other layers.
thanks all