View Full Version : HELP a student finish his final

05-08-2014, 11:44 AM
I'll preface this with the fact that I started working in Lightwave three months ago, and have been enjoying learning basic animation, and want to keep going with Newtek in my future :lwicon:

I'm trying to work through some scenes with simple bullet dynamics (I have a book above a desk with gravity applied to it, and a wind force moving through the room with an open wall), and every time I position an object, key it, and then apply a rigid body to the dynamic object, and a static body to the room/desk, then activate dynamics to run a preview simulation, my object gets inexplicably moved to a different location below. I just need to fix this problem I've been having in a few scenes, tweak my lighting, and I'll be done.

Help a brother out?


Ryan Roye
05-08-2014, 12:27 PM
- I recommend setting the shape of your dynamics objects to "Box", or "Sphere", or "Convex Pieces" (Convex pieces is kind of like an auto-proxy setting; it isn't a silver bullet, but it works most of the time)... only use the default of "mesh" when you *really* need detail suitable for extreme closeup shots. Box and sphere are the fastest of all the options.

- Disable dynamics (the checkbox at the top of the bullet dialogue)

- Move the items in your scene where they need to be, and in the object's activation tab, notice "Initial Activation". Set this to "activate on last key". What this does, is that it takes the very first keyframe in the simulation and uses that as the start point. Alternatively, you can use the "Start Sleeping" option to make the dynamics object only come alive when it interacts with forces, in which you could tap it with a collision bullet dynamics object to nudge it into activation.

- Re-enable dynamics to see your result. Note that for complex simulations, you may need to press the "Update" button when you make changes depending on how heavy the calculations are. In the majority of cases... at least as of LW 11.6.3, you should not have dynamics enabled at all while moving around dynamics objects.

05-08-2014, 12:34 PM
I'd have to see an image or two of what you're talking about. Can you get some screen captures before and after your object "gets inexplicably moved to a different location ...".

05-08-2014, 02:16 PM
Hey Bubbles,

For future reference, if you need help with a scene you will get the best answers if you package your scene and upload it as an attachment. (Sometimes this isn't an option.) This way rather than mere speculation other users can look at specifics and point out errors. Heck, sometimes they will even fix it for you and repost it already corrected. (But you wouldn't learn as much that way.)

And welcome to the Lightwave Community!