[Tutorial Preview] Gore Mesh & Dismemberment Tutorial

[n00854180t]

@Chosker;426150

hey there,
I’m the author of the original UDK tutorial so I’m obviously interested in this

I’m glad to see that this is partially there in UE4 because any other method I’ve heard of doesn’t seem satisfactory. the L4D2 method seems to always completely destroy what you chop off - sever the head and then there’s no head to be found, which is good enough if you have weapons that explode, but not for blades that just ‘cut’

Yeah in the L4D2 system you would have to just spawn those things as static meshes separately.

you mention preparing the gore meshes, how does that work?
in UDK it was super nice because there was this partial mesh weight swapping, which means that for multiple cuttable body parts the rest of the parts remain intact. for example in a model that you can chop off the arms and head from the body, if you chop one arm the other arm and the head are still properly stitched. are you accounting for this?

So yeah that’s I guess the part I was wondering about as well, though it seems answered this already.

@;425589

Glad to see people are excited about this.

So, to answer the questions:

• Yes, you use this just like the old UDK BoneBreak. Typically, you’d have one or more gore meshes that have the limbs separated, the vertices weighted so that the severed parts are entirely weighted onto a single bone, and at the point of dismemberment, you add new topology to cover the holes, typically textured with bloody meat-like textures. Upon death or dismemberment, you hide the regular mesh and show the gore mesh and then call Break Bone.

Ahhh right, so if I understand completely, it doesn’t have the full functionality of the partial weight swapping

• I’ve read the L4D2 paper. IIRC, they do most of their cool stuff in the shader. I’m curious to see how you’ve done that in UE4, but I definitely can’t promise I can go further than you have.

Kind of. The main thing their shader did was mask out part of the character via the material in an ellipse shape. What I have now does the same, though it doesn’t yet use the ellipse, just a sphere.

So you’re able to feed in a 3D hit position and that area will be masked out in a sphere.

Aside from that, it was all about spawning a gore mesh into the wound cavity. They pre-prepared a bunch of low res wound meshes based on a high-res internal organs setup, and then spawn those into the hole made by the ellipse-mask. The wound meshes are also weighted to the skeleton so that they would deform right. Their wound meshes covered, AFAIK, the entire inside of the body cavity, so that they can mask any area out and have it work properly. That’s for the torso, at least. Legs/arms and the head were different and used caps.

Not being an artist, doing the wound meshes is not something I think I can do with any quality, and there are places I can make more progress on my project, so that’s why I just uploaded it as is.

As far as extending it to use the ellipse, that’s not a huge deal to get a proof of concept working, but it’s not hard either, it’s just a matter of passing in the forward/right/up vectors and size parameters for the ellipse instead of just leaving it as a circle/sphere.

After going through the white paper and also finding some slides that showed the art side of it, ultimately IMO the real “magic” of the L4D2 system is all in the wound meshes themselves, the masking, which is really all the shader seems to do, is actually really really simplistic.

Edit: The last thing is that for skinned meshes there’s a bug with my implementation such that the mask-sphere doesn’t follow the skeletal mesh animation, which of course is a problem.

[Chosker]

@;426200

To be perfectly honest, I’m still researching the gore mesh. From what I’ve seen, very little UE3 functionality was removed when they moved to UE4. Some things were - where they relied on a third party library, or where they completely rewrote something - but a lot of the underlying core functionality is nearly identical (at least in terms of API calls) to UE3. So, I need to figure out if the partial mesh weight swapping is available and just not exposed to Blueprint, or if it’s simply not available in the engine period. From there, I’ll figure out an approach.

If the partial mesh weight swapping isn’t available, I’ll need to see if it’s something that is within my ability to add. If not, the only way to properly deal with it that jumps to mind would be separate gore meshes for each dismemberable limb, which is inefficient and less than ideal.

tl;dr: Still researching, don’t know for sure yet.

thanks for the info.

even if the partial weight swapping is there somehow, UDK had the plus of handling the alternate weights within the same asset, and the importing of it happened in the editor.
for me the ideal solution would be without having different versions of the mesh as assets based on X and Y or spawning new actors for the pieces that fall (in UDK it’s all the same actor), but I guess in the end I’ll work with whatever there is.

@n00854180t;426400

After going through the white paper and also finding some slides that showed the art side of it, ultimately IMO the real “magic” of the L4D2 system is all in the wound meshes themselves, the masking, which is really all the shader seems to do, is actually really really simplistic.

it does sound like a time hog

@n00854180t;426400

Edit: The last thing is that for skinned meshes there’s a bug with my implementation such that the mask-sphere doesn’t follow the skeletal mesh animation, which of course is a problem.

for this the only solution I see is to make the equivalent of UDK’s HitMask, i.e. painting the mask-sphere into a texture (that converts world coordinates into local UV coordinates).
otherwise I don’t really see a viable solution to make the mask-sphere follow all animation and deformation.

[SP]

@Chosker;426504

thanks for the info.

even if the partial weight swapping is there somehow, UDK had the plus of handling the alternate weights within the same asset, and the importing of it happened in the editor.
for me the ideal solution would be without having different versions of the mesh as assets based on X and Y or spawning new actors for the pieces that fall (in UDK it’s all the same actor), but I guess in the end I’ll work with whatever there is.

This is where I am stuck at. The alternate weights are part of my enemy mesh and it supports bonebreak, but the current plugin is not giving proper results for organic joint weight blending. We have it partially working, but without that feature it might give limited results vs the old UDK method. And agreed having it feed from same mesh was a nice feature and saved the annoyances of having variations to import.

Once it was exposed in UDK, EPIC had this setup real nice from adding it for Gears of War. It was also used heavly in Killing Floor 2.

if you want to use my enemy skelmesh and animations/blueprint to test any mesh weighting system you wanted to try adding, let me know and i can zip that over. Having it working on organics is defiantly where this feature shines.

[n00854180t]

@Chosker;426504

for this the only solution I see is to make the equivalent of UDK’s HitMask, i.e. painting the mask-sphere into a texture (that converts world coordinates into local UV coordinates).
otherwise I don’t really see a viable solution to make the mask-sphere follow all animation and deformation.

That’s what it’s already doing, actually - there’s just a bug in that the position is not being converted into the local space of the actual mesh, but instead the character’s local space.

[anonymous_user_fb692cdc]

@Aesthetic Games;426509

if you want to use my enemy skelmesh and animations/blueprint to test any mesh weighting system you wanted to try adding, let me know and i can zip that over. Having it working on organics is defiantly where this feature shines.

It wouldn’t be bad to have a good test case. You can send it to my e-mail or using an IM here and I’ll see if I can get it working.

[DavidMcL]

I know it has been said. But you are the man! This is fantastic. And I look forward to any tutorials you put out.

[Silpher]

Shameless lurker here… Just wanted to let you guys know I check this thread at least every day to see if there’s anything new.
Alas I’m not really proficient in Blueprints or C++ so I can’t really contribute in any way but if you ever need a textured character or some other model or let me know.
I’m an eternal optimist so I won’t assume this project is forsaken.

Cheers!

[n00854180t]

@Silpher - Would you possibly be interested in helping make generic (e.g., can work with many characters) wound meshes for the Left 4 Dead 2 style system I’ve been working on?

WIP - Dynamic Left 4 Dead 2-Style Wounds/Dismemberment

[SP]

@;441997

Is this now possible using strictly blueprints with the BreakBonePlugin?

As far as I know this does not currently work with weighted meshes. Maybe im missing something but in my project the joints that can be dismembered remained broken as shown below altough they get cut off just fine. Any thoughts on what could be going on here ?

[n00854180t]

Yeah I think it doesn’t have the code it needs in the engine to determine which skeletal meshes should be used in the unbroken state.

[SP]

@n00854180t;445011

Yeah I think it doesn’t have the code it needs in the engine to determine which skeletal meshes should be used in the unbroken state.

Yeah thats what ive figured… as a Moderator what do you think is best avenue to get proper Bonebreak functionality requested and exposed by EPIC? As of now UE4 has no comparable system for non fatal dismemberment and i know it was on the to do list back in the beta program roadmap. Sadly, it seems to have disappeared from the radar completely now.

Whats currently exposed as Bonebreakfeels broken and useless for project use. It is misleading from the more robust UDK Bonebreak functionality for dismemberments.

Can you point me in the right direction?

[n00854180t]

Well I don’t know about getting BoneBreak added to the engine (best way to do that is just to make a request thread in the feedback forum), but if you’re able/willing to make some wound art you could use the L4D2 style system I mentioned in this thread, as the last kinks have been worked out from it, but it needs a specific type of wound mesh built to utilize it (though you can use the same set of wound meshes for multiple characters).

[nateight]

Curious what the state of the tutorials for this plugin might be. Played around with it for a minute but nothing much happens when I attach this script to a blueprintified character:

This successfully prints out a plausible location for the bone, but the dude just stands there, intact. I’m enough of a UE4 noob that this is surely due to my failure to properly prepare the mesh or something, but I’m not sure what steps I should take to correct this. Anyone have a clue?

[Harcarik]

It works fine, at least for me. I have also connected return value from ‘Get bone location’ to Impact location, not sure if that can make a difference.
This is very useful plugin btw, any chance to update it to 4.11?

[Slayer9292]

@;425323

I didn’t expect the level of interest in this. I’ve gone ahead and created a plugin that gives Blueprint users the ability to do bone breaks.

You can download it here:

To install it, just create a folder called “Plugins” in your project folder (if it doesn’t have one already) and then unzip that and drag the BoneBreak folder into the Plugins folder. The plugin adds two new blueprint nodes:

http://i.imgbox.com/LwCA9HVc.png

The Bone Break node does the actual… well… bone break, in case that wasn’t obvious. The first two pins are required. The first pin is the skeletal mesh to perform the bone break on. The second pin is the name of the bone to break off. If you want to apply force to the bone as it breaks, you can populate Impact Location and Force using data. You likely want to calculate this based on Hit Result data. The final boolean is experimental and untested, but allows you to ragdoll the broken part of the mesh. This is for situations where you break off a bone like the upper arm. There are two joints that make up the arm that you may want to be controlled by the physics system. Setting this to true should cause that to happen.

If you need the location of a bone for any reason, you can use the second node this plugin adds: the Get Bone Location node. It takes a skeletal mesh and bone name and returns a vector identifying that bones location in world space.

Let me know if you have any problems with it. It has both editor and game binaries for Windows & Mac plus game binaries iOS and Android, but it has not been extensively tested.

Note: This should work on Mac and Windows, both in editor and game binaries are include. I’ve also included, but not tested, iOS and Android game binaries. I have not included either editor or game binaries for Linux - sorry - but the source code is included.

I’m unable to download the file from Drop Box. I get this

Error (403)
It seems you don’t belong here! You should probably sign in. Check out our Help Center and forums for help, or head back to home.

[Xter]

@Slayer9292;518871

I’m unable to download the file from Drop Box. I get this

Error (403)
It seems you don’t belong here! You should probably sign in. Check out our Help Center and forums for help, or head back to home.

Same here. Could you reupload this plugin?

[n00854180t]

Hey guys, I had a copy of the plugin on my HD

BreakBonePlugin

[parker67]

Hi , any progress on the tutorial?

I’m looking at using this in my next project and jist wanted an example to refer back to.

Thanks

[Cpt.Trips]

Is it possible to compile the BreakBone plugin for 4.12 from the download?

[Ixiguis]

Plugin compiled for 4.12:

Dropbox - File Deleted