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bigwil357

RBD Material Fracture Door hinges and constraints

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Posted (edited)

Hello. 

Ive been struggling with this scene for a while and ive exhausted myself trying to figure this out. I would like to make a door explode, and leave some of the fractured door swing on its hinge. I would possibly like to destroy the rest of the house later. Ive been self studying for a while, and i understand how the constraint network in dops works, how glue and soft constraints work, but im unsure how to approach this effect. I think im doing the right thing in SOPS, but im not getting the results that i want. I understand adding the active attribute to the featured geometry to make an inactive area as well. I would like to do do somethging similat to this video with the door swinging by the hinge, as the remained of the door remains fractured. Look here https://www.sidefx.com/products/houdini/whats-new-17_5/  the video is at the "interactive RBD constraint" section.

Some of my issues are;

Why does the geometry fall when the sim starts? I understand that Glue is on/off, but i still have it fall once the sim starts. (not including the inactive area)

How to constrain two objects? If i would like the wood frame to be glued to the wall, how can i do this? Is it just a matter of drawing lines (RBD constraints from lines) to connect the objects together? Ive also tried using geometry as constraints, with 0 luck as well.

Should i just use an animated bounding box to make the area "active", and then have the sphere break the door? Or is there a way to have the door break, only where the sphere collides with it?

I am familiar with DMM in maya, and im not sure if animating a passive/active region is the way to go, or is there a better method?

 

Odforce_hinge_scene_zipped.zip

constraints from curvessidefx.jpg

Edited by bigwil357

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I don't want to sound mean or discouraging, but your network is a mess. It really does look like you have spent a lot of frustrating time working over and over it. I sympathize, I truly do. I've been there, many times. In essence you're trying to solve several problems at the same time.

The easiest, quickest fix is to start with a simpler setup(s) to understand the essence of a constraint networks.

In the attached file I've included a couple standard help scenes (I love the scenes included in the Houdini help docs and so should you) that should help you along. And I've included a quick custom setup showing the rbdmaterial fracture generated constraints. Do not use packed, you have to see your constraints previewed in red or they're not there, name your glue constraints "Glue" or they won't work.

Best of luck!

constraintHelp.hip

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On 7/18/2019 at 12:00 PM, kleer001 said:

I don't want to sound mean or discouraging, but your network is a mess. It really does look like you have spent a lot of frustrating time working over and over it. I sympathize, I truly do. I've been there, many times. In essence you're trying to solve several problems at the same time.

The easiest, quickest fix is to start with a simpler setup(s) to understand the essence of a constraint networks.

In the attached file I've included a couple standard help scenes (I love the scenes included in the Houdini help docs and so should you) that should help you along. And I've included a quick custom setup showing the rbdmaterial fracture generated constraints. Do not use packed, you have to see your constraints previewed in red or they're not there, name your glue constraints "Glue" or they won't work.

Best of luck!

constraintHelp.hip

Thanks you very much for your reply!

 

I actually used the help docs to create that scene. guess i still have alot to learn. I had no idea that using packed geometry was the issue. Its seems like i always see people using the RBD packed object, so using the RBD fracture node was new to me. But why is this? Is it because im using constraints generated by the RBD fracture material?

Also when it comes to naming constraints, i dont have to use a wrangle node and manually type them in, right? I thought that the RBD constraint properties node took care of all of that. And i also was under the impression that if you have the same constraint name, in SOPS and DOPS that everything should work fine.

One thing i am curious about is why and when do you delete the channels on the Overwrite with SOP parameter in the Constraint Network node in dops? Do you do this every time you use a SOP Solver, or is it only used in specific instances?

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Hey guys. Still working with the sim. Ive given up on the door hinges. At this point, i am just trying to have a decent simulation. 3+ months, and this is what i have come up with.  

Learned about constraining 2 objects together, which seems to work, but things still are not working as i expect them to. When i try to use the Point Wrangle in the SOP Solver, i just dont feel like its working, so i switched to animating the constraints with the DOP geometry. I would rather have the constraints break by torque, angle, etc but it just dosent seem to work for me. 

Another issue is whats the best force to break there objects? Ive used sphere geo, and now metaballs. Does one give a more "explosive" look than the other?

Lastly is how to get the pieces to just settle after the sim. Some sims are more stable than others, but i dont know why. Ive played with the substeps and collision padding, but still get issues. 

Any help would be appreciated. Ive learned a TON, but still cant seem to pull off a simple sim.

 

File attatched. House geo is in previous attatchment

LostHouseCON2v4.hip

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