[Custom Build] Blender Fracture Modifier

(mcbeth) #1681

I recently downloaded a build from (http://kaikostack.com/fracture)

my question, are there anything contained in the config file that is essential the the fracture modifier, scripts and whatnot, I had to cut off access to the one the comes with the build for my blender config to kick in I use fracture modifier builds exclusively and have been using the last released version but I have scripts, themes and settings that I prefer to be enabled by default and don’t really want the hassle of doing it all over again


(scorpion81) #1682

The only additional part of the Fracture Modifier is the Fracture Helper Addon. The most up-to-date version can be downloaded here:

The file “fracture_helper.py” is the one you need.

It also includes an “Alt F” pie menu, which can be enabled in the addon preferences. (so the other separate pie menu addon being listed there is not necessary atm).
Except the build and the addon there is no other optional stuff for the FM.

(mcbeth) #1683

thank u very much

(vihreä) #1684

Are you familiar with houdini simulations, I wonder how similar this fracture addon is to houdini. And could these fractures be controlled I procedural ways?

(scorpion81) #1685

Hmm, what simulation result do you want to achieve with the FM ? Do you have a concrete project / vision in mind ? What should break how etc ? As in, a certain scene with certain objects etc ?
The addon’s purpose is to attempt to reduce some initial click / setup work for certain things. E.g. if you have an active object with an FM on it and want to add helper objects (with particle systems) you just need to additionally select all other helpers and click “Generate smaller shards” in the addon.
Or if you want to create a fake cloth object (tearing with FM) you can use the according functionality in the addon too.
Without the addon you just have to do more click-work to set it up.

(vihreä) #1686

I was just thinking if it was possible to control fractures with nodes like in houdini. Also I can’t get the inner smoke to work. To use the dust I need to make the ground dynamic brush, right? But how to make the inner smoke work? And both same time?

(IIBit) #1687


I have a problem with FM. I building a scene, which was working very nicely, but at some point every fracture I do starts acting weird when I simulate. In stead of falling, the shards start acting very erratic. Also, no simulation is working anymore. Smoke isn’t working anymore either. Everything I put in there is not working anymore. Is there a limit of things you can simulate? Did I cross that limit? It isn’t that complex of a scene ( I think ).

(jensverwiebe) #1688

Updated Linux dev build:

Branch: fracture_modifier
Revision: 982720c
Submodules: locale 1bbc9bd addons 2609a10 addons_contrib 8a3b944 tools 7695e14
OS: GNU/Linux, Architecture: x86_64, GLIBC: 2.19
Builddate: Mi 10. Okt 10:11:48 UTC 2018
Filesize: 104268500 byte
Sha256sum: 32d01621d29326983b0029b1d16a93c38c4f90c0d42665aac3e7a48bb880a5f7
URL: https://www.jensverwiebe.de/Blender/blender_fracture_modifier_linux64_latest.tar.xz


-fix for autohide with fractal (could leave holes near inner edges before); fractal/fast bisect should now also take extra objects / helper better into account
-do not show dump writing routine in dump any more

Cheers … Jens

(scorpion81) #1689

Do you still have this blend file which shows the erratic behavior ? I would need to look at it, check the settings and maybe run it inside a debugger session. Else I can only do guesswork… What means “erratic” in this context ? Hmmm, but i might have an idea… if you use the old build from Oct 2017 or so, it can happen that the shards order gets messed up, means if you have multiple FM objects, their shards look kinda scrambled. Smoke has is own set of issues (due to usage of particle systems for emission).
There is no limit to simulate… well maybe if you have more than 5000 or 10000 shards, things become awfully slow, but should not behave erratically. (unless there is a bug i am not aware of).
Anyways, i would need to see that blend file (or a simpler reproduction which also shows that erratic behavior you mentioned). Maybe its just wrong settings somewhere, or it is indeed a bug. But before, try the graphicall version or the kaikostack version; for windows those are the ones which are not too old yet. If you use linux, try jensverwiebe’s build.

Edit: Dang, overlooked the line that you already use the latest build… hmmmmm

(scorpion81) #1690

No, there is no nodal control of fractures in the addon. Just a couple of operators and settings to simplify certain fracture setups.
Inner smoke should be set up if you pick an object with FM and click “Inner smoke” in the addon. After that you can add dust too (uses the smoke as forcefield iirc) and debris as well (particle dupli objects.)
And yes the ground must be a brush, and if you use debris, it should have a collision modifier too.
The inner smoke operator of the addon just executes the “Quick smoke” operator basically and additionally tweaks some intial settings.
The inner smoke works via particle emission controlled by a vertexgroup being filled by dynamic paint. Thats why the ground (or other objects) need to be brushes. The FM object is the canvas there. But note that I had to alter the particle system (in the code) slightly in order to let it respond to dynamic vertexgroups. In the official version of blender, if you change the vertexgroup dynamically e.g. via dynamic paint, the emission wont be changed (unless you use Hair particles, but this is another story)

(JTA) #1691

To new users - make sure you check the first post in this thread to find the documentation link and look over the docs. FM is an open and experimental system so we don’t confine the user with a robust UI that keeps you out of trouble. Instead we just post “don’t do this or it will hurt” notices in the docs. This gives an unparalleled freedom for experimentation and discovery.

So check out the doc to help you with workflows and experimentation ideas. If you try to use the FM without at least reading the docs for an overview then you’ll wast a lot of time. New docs are coming soon but the current ones are more than enough to get you started on the right path.

Fracture ON!

(wolfie138) #1692

is it possible to use the Fracture Modifier to simulate bullet hits on a wall? i’m thinking you’d have to place individual particles, which might be tricky. i’m wanting to punch out some bullet hole craters in a wall for a little animation i’m working on.

(scorpion81) #1693

I have made an example file here.


Here i have a remeshed particle system (metaballs serve as “bullets” here) which is made a “final deforming” rigidbody and is a rigidbody trigger.
The wall is just fractured to 1000 pieces and is animated / triggered. It also has a constraint setup with clusters, which allows some well … semi-realistic collapse of parts so they dont get stuck in the air after their surrounding parts already fell down. (you can switch off this behavior by unchecking “Activate Broken” in the constraint settings).

Furthermore you can vary the wall thickness (scale and refracture), the wall piece count (note things will become slower quite quickly) and the particle count.
Optionally you could use a model of a bullet as dupli object so things look better. but the remeshed metaballs + rigidbody are necessary for the rigidbody interaction.
Technically, the metaball rigidbody is still only one rigidbody, not multiple ones. But its mesh shape is manipulated by the particle and their collision.

(Romanji) #1694

I would simply prepare the wall by creating the holes (with booleans) beforehand. Then only shatter and simulate the volume inside the hole.
Its more destructive (as workflow) since you have to determine the holes before, but it is better to art direct and less intense to simulate.
But if you have a lot of bulletholes (machinegunfire?) i would go with a full procedural approach.
Another thing is, that you have to decide if you want to simulate it at all.
Usually bullet holes in concrete walls aren’t that deep and big. You might get away with doing it completely with displacement maps (or even normal maps) and particles.
Since everything happens very fast, you might not need the accuracy of a proper simulation. Spawning dust and debris when the bullet hits might be enough (in addition to punching the hole in the wall with displacment maps).
I’ve done both to test out such a scene and i found that it works pretty nice.

(wolfie138) #1695

Thanks for the replies. That file’s great, scorpion, thanks for that - i originally was thinkng of just shooting craters in the wall but that looks cool so i think i now what to use that approach - have my target half-hidden behind a wall that just gets demolished by the gunfire. i couldn’t get the smoke/dust bit to work properly when i was messing about w/ my own model is it possible to have a little spurt of dust where each of the bullets hit, to simulate the impact, rather than from all the internal fractured faces?

thanks Romanji, couple good ideas there, maybe combining that dust/shards idea w/ the fracture sim. have to do some testing over the weekend.

(scorpion81) #1696

I have modified my example file to include smoke and dust:


I have just clicked on “Inner Smoke” in the addon, and adapted the size of the domain (which is created by “Inner smoke”).

Furthermore, only select the wall and click “Dust”. Optionally you can hide the smoke particles from rendering, so you can see the dust particles (there are small dupli objects on them) better.

And of course after creating the smoke setup, you may need to tweak the smoke settings to adjust them to your needs.

Important: the object which basically spawns the “bullets” needs to be a dynamic paint brush.
Best is you select the bullets object and click “Create Brush” in the FM addon.
Then the bullets will paint on the wall’s canvas near the impact locations and there you should see smoke and dust being emitted.

(wolfie138) #1697

thank you very much for creating and sharing those files, scorpion, that last one looks amazing. going to have a good play w/ it at the weekend. i’ve never used dynamic paint before so that’s something else to look into.

(wolfie138) #1698

Hmmm…after a bit play i’m trying to set up a wall in my actual animation file; i’ve set up all the fracture etc, but when i’ve set Animated and Triggered, it’s still just all collapsing immediately w/out waiting for my Trigger - is there something i’ve missed? can’t see anything immediately obvious when comparing to my test file.

(scorpion81) #1699

hmmm its hard to say without seeing that particular blend file. I would need to have a look. Could be everything from simple incorrect setting to bug.

(wolfie138) #1700

Well, it seemed to be because the trigger was close to the wall, which doesn’t seem likely because i think you’ve got yours closer in your tutorial vid, but when i lifted it up and let it drop further it started working as i wanted. I was fiddling w/ trying to keyframe the drop though so might have messed something else up, but anyways i ended up creating a new wall and trigger and it’s back to working fine again :slight_smile: