How to break a pole(Request)

#1

I am currently playing with the dynamics in Maya. I’ve played a lot with nCloth and general rigid body dynamics.

What would be involved if I wanted to crash an object into a lamp pole, have it bend and then cleave off.

#2

Here is a little scenefile that does roughly what you are asking.

The basic workflow is to create a simple as possible geometry (smooth later if needed) then detach the edges you wish to break along. Then make this cloth and create a component to component constraint between the points along the detached edges. Make the bend/stretch resistance and substeps high. Also generally fullQuality self collisions are better with a low collision width. Then make the restitution angle and tension both low… the settings will depend on your scene. When these are low the bend and stretch will deform allowing the rest shape to change when the shape is under stress. Then to allow the shape to snap lower the glue strength on the constraint. In this case I animated it going lower, which sort of simulates the gradual weakening over time as the joint is stressed, although one could just suddenly key it to zero on the frame you want it to snap.

Depending on the mesh something additional can be to do a merge vertex on the output cloth mesh followed by a smooth normal. Also you may wish to do a smooth on the output mesh for better detail. Note that the merge will cause the topology of the output mesh to change when it breaks, but the input mesh still has a fixed topology.

#3

Thanks so much, this is exactly what I need. I have managed to mimic your scene quite accurately.

Here’s the simulation I’ve managed to get with your assistance.
https://www.youtube.com/watch?v=rovr9cyKQDg&feature=youtu.be

#4

I have been attempting to run the simulation on a more complex object(A metal suport beam). I am getting way to may deformations and intersecting edges. My current dilemma is the beam intersecting itself.

As you mentioned, I should run the simulation on the most basic of forms. If I ran the simulation on a primitive shape, is there a way I can then apply the simulation to the support beam (kinda like baking the simulation into another object)? I have this beam but i am unsure how to set it up so the core stays solid. The core just flys outwards once the beam has been impact. Also, I have tried quite a few things related to self collisions but I cannot seem to stop edges colliding and passing through(pushed iteration tests up to 60).

What are input and output cloth meshes? I am having difficulty finding free documentation on them.

#5

Hey, I had the eureka moment on finding the documentation.

http://download.autodesk.com/us/maya/2010help/index.html?url=Creating_nCloth_Clothing_Improving_the_quality_of_the_nCloth_simulation.htm,topicNumber=d0e54472

Under the quality setting, “Self Trapped”.