Constraint help

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

Thread Tools Display Modes
  01 January 2013
Constraint help


I have been animating a lot of steam engines lately and have been able to animate the models each time. However, the pistons are horizontal or vertical in orientation and have not been a problem. In those cases, my approach to animate the Y-axis of the piston itself while the piston rod follows the circular motion of the crankshaft has been to use a constraint setup using Cactus Dan's CD PSR Constraint to align a null to a circle and to move on the Y axis only. That circle is made editable and the pivot point moved to the bottom of the circle. That circle is linked to a second circle that I rotate and the null moves up and down. Perfect. I link the piston in the appropriate position and it's perfect.

However, I am now animating a radial engine and the first piston is rotated 22 degrees on the Z axis. I tried linking my null setup to a new null and rotating that 22 degrees to match, but the constraint still sees Y axis as global Y axis. I tried clicking the local coordinates option in the plugin, but that doesn't solve the problem. Any ideas how I can rotate my Y-axis rig 22 degrees (or more since I have 9 pistons to rig) and maintain a local Y-axis to point the null in the correct direction? I hope that makes sense!

Screen shot attached:

Thank you,

  01 January 2013
Btw, here's an example of one of the animations I did recently, if that helps at all:
  02 February 2013

Well, I don't know how you've set up your piston rig, but here is a simple example of an angled piston rig using CD Constraints.

Cactus Dan
Attached Files
File Type: zip (55.8 KB, 11 views)
It doesn't matter what people say about you, just as long as they're talking about you., cactus3d-Plugins, CD Character Plugins forum
  02 February 2013
Thread automatically closed

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.
CGTalk Policy/Legalities
Note that as CGTalk Members, you agree to the terms and conditions of using this website.
Thread Closed share thread

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Society of Digital Artists

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump

All times are GMT. The time now is 11:09 PM.

Powered by vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.