Jump to content
g17

Fractured pieces of a deforming object acts strange after collision

Recommended Posts

Hi guys,

this is my first post on odforce.I am a bit new to RBD in houdini.I have a rotor rotating at the object level which is being prefractured usining voronoi fracture before sending it to dops.As the rotor colliides the ground the fractured pieces acts strangely.

I tried to follow the "choreographed tube breakup" example .but its working for static object but fails at deforming (rotating) object in my case.

have look at the attached file and please help me with this issue.

cheers,

g

2_Rotor_shatter_.hipnc

  • Like 1

Share this post


Link to post
Share on other sites

you don't want deforming geo since your rotor is not necessarily deforming (deforming geo will update geometry of your RBDs each frame making is as erratic as you see in your file) and instead of animating transform of the object which will get ignored by rbd since simulation is taking place you can just set initial angular velocity of your rotor

instead of RBD Fractured Object and RBD State voodoo just use RBD Glue object, unless you have something else in mind, or you could use Glue Network Constraint if you were using Bullet

2_Rotor_shatter_fix.hipnc

Share this post


Link to post
Share on other sites

Thank you anim.for the file.

I am trying this test for a helicopter crash sequence ..(some thing similar to Black hawk down).so i want rotor animation from sops...Is there any other way to acheive this same effect while using the animation from Sops.

Thanks

Share this post


Link to post
Share on other sites

try to avoid pure sop animation (deformation) while you can

if your rotor/helicopter is animated on object level, you can import the motion using RBD Keyframe Active DOP and switch between object level motion and simulation (active state)

when you switch to active it will take velocities from object movement so it will appear to continue with the motion

2_Rotor_shatter_fix2.hipnc

  • Like 1
  • Thanks 1

Share this post


Link to post
Share on other sites

Thank you for helping me tomas and it works fine for me.

Share this post


Link to post
Share on other sites

This is exactly what I'm looking for! I recreated this and It works great but constraining it to a helicopter chassis causes issues. Whats the best way to parent or constrain the blades to the body?

Share this post


Link to post
Share on other sites

This is exactly what I'm looking for! I recreated this and It works great but constraining it to a helicopter chassis causes issues. Whats the best way to parent or constrain the blades to the body?

Hi kstrod. Did you manage to solve this problem? I have the same issue..would be great if you can share your solution! :)

Share this post


Link to post
Share on other sites

Hi kstrod. Did you manage to solve this problem? I have the same issue..would be great if you can share your solution! :)

 

Hello everyone!

I will give my solution to constraining chassis to helicopter. I use two constraints. rbd angular constraint and rbd pin constraint. Both of them have the same location and goal objects. (Constrainted object is helicopter and Goal object is chassis). Simple and fast.

Share this post


Link to post
Share on other sites

Sorry to revive an old thread but could someone post an example file with this setup? I've almost got mine working but its just missing something, my pin constraint doesn't seem to stay in exactly the same place.

rotor_dyn_spin_test.hip

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×