Positioning treads along a spline path

Hi guys

I'm trying to orientate and position tank treads along a spline path.  The original tread is positioned perpendicular to(across) the path with the centre on the path.  I am using the Spline Snap tool with the settings as shown in the image.  I also used Rotation Snap Selection to orient the tread to the path before activating the tool.  As the image shows the tread copies are positioned flat on the z axis as required but are not following the path on the x and y axes and are still not oriented properly.  Any clues on how to get the treads to follow the spline path and orient correctly?

Cheers
Mal

Hi Mal,

Use "Instance > Spline".

I have to go to work for an hour or so, I will post info on how I have done that (create tank tracks along a path), when I get back.

When using the snap function, place the object (the tread) with its pivot in the world center. Any deviation will result in an offset from the path.

[Edit]: After that it's a case of trial & error as to orienting the object.

Hi Mal,

OK, first, the reason I put forward using the "Instance > Spline" is because with that Tool, you can make changes with real time feedback (no need to exit the tool to make possible various changes).

So for simple example:-

I created a simple track link. It's bounding box center is at world 0,0,0 as placement on the spline is calculated from world origin (the objects pivot location is ignored). Its current orientation is not really that important, as it can be changed:-


With a simple path added.


Select both the object(link) and the spline, and start the "Instance" tool, select the "Spline" tab in the options window. That will give a result similar as show here, with a default number of instances:-



If you find that the link is not in the correct orientation, select the Object/link(no need to exit the "Instance" tool) and rotate the object(link). Here, although it was correct before, I have rotated the object(link) just for example.



When in correct orientation, change the number of instances to suit.



You may find that the link size is not correct, and does not divide the length of the spline evenly, so you can either select the object(link) and scale with manipulator, or as I prefer, use the scale option in the instance options.



That is a quick method, but is prone to error of alignment due to tangency. It can be done more accurately, but needs extra steps/work. I can post info on the method I use for that if required.

Hi Vaquero and Steve- thanks a lot for your advice.  The key was to place the object at world centre to prevent offsetting.  Thanks also Steve for your detailed explanation - much appreciated.  I knew I could rely on forum members to help me out.

Thanks again guys.

Cheers
Mal