Multibody object 2d motion vector/motion blur problem

janne_suhonen
Posts: 10
Joined: Thu Nov 06, 2008 1:12 pm

Multibody object 2d motion vector/motion blur problem

Postby janne_suhonen » Thu Jun 16, 2011 9:02 am

When I simulate multibody stuff in Realflow and bring it back to Maya, my objects pivots are moved to the same place where they are in Realflows multibody. I understand that, because Realflow considers multibody as one object and you really can´t have multiple pivots inside one object and this is fine, until you want to render 2d motion vectors or motion blur out from Mental Ray. Then shit is hitting the fan, and your motion vectors are going all over the place (at least when you have heavy rotation and movement in your scene (for example underground explosion rocks and debree)).

I have this workaround, where you duplicate animated objects (from frame 1, without animation), center those duplicated objects pivots, parent constraint (with maintain offset on) those to animated ones and then bake translate and rotation animation to new objects. Now you are having proper looking animation curves and you can render motion blur just fine.

I was just wondering if anybody knows better and easier way to fix this problem...I´m using Maya and don´t know if this problem exist in other softwares too..


Anaxarchos
Posts: 843
Joined: Wed Mar 19, 2008 4:21 pm
Contact:

Multibody object 2d motion vector/motion blur problem

Postby Anaxarchos » Thu Jun 16, 2011 10:37 am

Are you using the Motion Vectors from Maya Mental Ray Passes or the lm2dv shaders?
www.fk-fx.com

janne_suhonen
Posts: 10
Joined: Thu Nov 06, 2008 1:12 pm

Multibody object 2d motion vector/motion blur problem

Postby janne_suhonen » Thu Jun 16, 2011 1:57 pm

mv2DToxik motion vectors. comping in Nuke... Co-worker said that 3d motion vectors could work and it can be turned to 2d. Problem occurs when you use standard remdertime motion blur too. When its starting to render and show those timesteps needed for motion blur in viewport, I can see that those objects shift position really drastically.


Return to “RF5: Rigidbody simulation”

Who is online

Users browsing this forum: No registered users and 1 guest