Destructible mesh / Custom

Hi.

I am trying to find information on the FBX generated chunks.
In the content example it shows how letters were predefined in the FBX.

However this is one little problem. When you open the destructible mesh in the content example all it does is default to vornoi and gives no indication what the source looks like.
I searched youtube and google but i cannot find information about this…

Even the documentation does not shed any light on it. Except that it can be done.

Hi Crocopede,

The Destructible Mesh in question, 1.2 - Custom Destruction, was made by using two separate meshes. The first is the panel that is in the editor, the second is a custom mesh created with the cut out lettering in a modeling application. To import that as custom chunks for your mesh you would need to use the “Import FBX Chunks” option in the toolbar.

I have a tutorial here that walks through the steps and explains a little more: [TUTORIALS] Photons Be Free: Mini-tutorials and other curiosities - Community & Industry Discussion - Epic Developer Community Forums

In UE4’s Fracture Editor there is only the one fracture method, Voronoi, that is used. If you need further styles of fracture, such as Slice and Cut-Out, you’ll need to use PhysX Labs.

Feel free to ask any questions involving destructibles as I’m very familiar with the system and PhysX Labs. :slight_smile:

Tim

Awesome thread. Thx… will go through the information there… looks like what i need.

I have one question though.
What your opinion is on the best solution for the job?

I have a tower i am destroying in a specific scenario.
Right now i am going with a Phat asset with a linear breaking threshold.

What do you think would be best for this… Phat, Destructible mesh or Physx Lab?

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In all honesty, if you’ve got a good look with your PHAT breakage at the moment that may be the best route. The destruction system in UE4 needs some love to get it into a better state, but at the moment it’s not a high priority.

For instance, in setting something like this up, I would use a couple of destructible mesh planks created in PhysX Lab with the slice tool. Using this tool I can create a DM that would look like splintered wood. This mesh would be only several pieces that I could easily assemble in UE4.

I would make sure that “Form Extended Structures” is enabled in the Flags tab of the DM settings. This would enable any static DMs to “stick” together if they are in contact. However, at the moment this method will work, but there is a bug that only allows the first placed mesh to receive damage, once the first mesh has been destroyed the others can receive damage. Ideally you’d be able to apply damage anywhere on the mesh and it work.

As an alternative you could create fewer fractures and use a modeling program to create a separate mesh that is your custom destruction mesh. This can be used to import these custom chunks as your destructible chunks, like the tutorial I have above. The idea with that is that if you take a single plank, and break it three times, you would now have three separate meshes in your custom mesh. One for each chunk you’d want. When you import in the Fracture Tool they will be their own chunk.

For larger objects like this, I would likely go the route of the second method I’ve described and I wouldn’t do a separate mesh for each plank, but instead break it up into sections that are destructible, like your ladder would be a single mesh that had custom destruction mesh , the first floor would be another, the second floor another, and so on.

With DMs, since everything is on the CPU it’s best to profile and see if you’re getting significant slow downs in this area. Usually keeping the DM chunks to lower than 75-100 helps on my home machine which is mid-spec at best. This can be different depending on the hardware. This is where using tricks like particle effects and removing chunks from the scene can help.

Thx for the advise Tim

Hi everyone.

Another question here…
How do you get your character to affect chunks of a destructible mesh?
I increased max chunk size so that the pieces do not block the player… but it appears it does not only not block the player but in fact completely ignores him and has no effect when being walked against.

Is there any way to see the collision of the destructible?

If you use the console command PXVIS Collision this will show the collision.