https://blenderartists.org/forum/attachment.php?attachmentid=503821&d=1509610555
Wow! Would you share your fire-setup (domain settings as well as shader + render settings)?
Alternatively you also could make the heli and the rotor animated rigidbodies, optionally ghost too (if they should not collide). This way the âdelayâ will be the same on all objects and they are matching again. I think the problem is here that the rigidbody sim is evaluated before the animation update step, using the values from the last frame. But changing this needs to be done carefully (in the code), it could have side effects.
@leorg
Slow Parent actually has some problems with collisions with the ground, so Scorps solution is the better choice. Note that you need to remove the Animated keyframe animation from the fuselage too, otherwise the delay will be reenabled during simulation.
Thank you all. Kai Kostack and Scorpion youre were right. Turned into frames, baked frames. The heli added the fractures and now they fly the same. Thank you.
Well you need to use other helper objects (put them in a group and pick this group as âextra groupâ in the FM). They can carry particle systems which you can use as point source (with âExtra Particlesâ) or you can use their vertices as point source (with âExtra Verticesâ). This way smaller shards should appear where you have more dense point clouds and bigger shards where the point cloud is more sparse.
but a automatic variable size fracture is not possible? without specific work made by hand.
About the patterns, I have seen a video with fracture modifier and bricks pattern, but I donât find the option.
Currently all fracturing methods available in the FM are particle based so you have to modify particle distribution in order to change shard sizes:
Keep in mind when youâre using constraints to keep shards together, breaking of an evenly fractured structure will also lead to chunks of different sizes in a natural way.
Having said this, it might be an idea to add a random factor to our cluster system to make it possible to have at least shard clusters of varying sizes.
Would be Great!! because actually my main problem making simulations, basic simulations, is the âfakeâ effect that I have when I see all the pieces of same size.
About the brick pattern, any words?
Other thing is⌠I want to use the modifier helper addon, but I didnât find after make the compilation and I donât find in addons list.
I have written a prototype script for brick patterns but itâs not yet in FM.
The helper add-on can be found in the âfracture-extraâ subfolder within the Blender folder. You have to install it as add-on the usual way.
Iâm just experimenting with the build now, and canât get the âGenerate smaller shardsâ to make anything other than 500 shards.
I select the object, then shift select my fractured object, and under generate smaller shards I can set that to â0â but still it generates 500 shards - If I then click on the shard generator object I find it has a particle system with 500 particles.
Also, I donât see the particles in the viewport as can be seen in the tutorial video on the fracture mod website.
Hmm, the problem here is we need to deal with multiple different objects. The particle system is placed on a helper object, while execute fracture only affects the FM object. And the initial âgenerationâ step is only for convenience, to quickly create the helper. In order to change the particle count, you can do it in the addon panel after the helper has been created. BUT, then you need to refracture the FM object, making it active and refracture from the Modifier panel or addon panel. Alternatively, you may click âToggle Automatic Executionâ on the FM object, so refractures are done automatically after changes. This way you can change the particle count and the FM object will auto-update (which can take long depending on the geometry complexity).
In the latest addon (2.1.3) there is even no particle amount input field unless you selected the helper object.
And by default the particle rendering is disabled now, you can either enable it in the particle settings of the helper or just select the helper (which is on layer 20, just to keep things cleaner in the first layer(s) and select âPointâ under 3D View Settings (its the 3rd option there, only visible when being on a helper object, being âNoneâ per default)
There is a quick tutorial for this here:
You can see all learning-stuff here: http://df-vfx.de/fracturemodifier/learn-fracturing/
Brilliant, got it now.
The next bit Iâm stuck on is motion blur - I have to convert the shards to real objects in order to get motion blur working correctly, right? My trouble with this, is that then the autohide/merge of faces doesnât seem to workâŚ
Such a cool feature though - this makes it so much better than the last time I tried to break stuff in blender!
Topology changing features such as Autohide, Automerge, Dynafrac etc. are currently not supported by deformation motion blur in Cycles which will automatically be disabled when mesh changes between frames are detected. This is something we cannot fix since the problem lies in the Cycles render code, the motion blur implementation basically needs to support changing topologies.
Solution: Either you donât use mesh changing features or you need to add fake motion blur in post like with After Effects.
No worries, so long as I wasnât missing anything.
The next question I was going to ask was how Iâd make something visibly and gradually crack slightly before shattering it? Basically I have a block of ice and I want cracks to form before it bursts open to reveal the logo inside. Currently I have an object that taps the top of it slightly a couple of times, but this displaces the shards a bit too far, and also the ice block visibly moves when itâs tapped. In my mind, some sort of dynamic paint that controls whether faces are hidden, not sure if thatâs something that is currently possible or possible in future.
I guess one way to cheat it would be to do two passes, one fractured, and one not, and then composite/mask between the two to have the cracks spread - this way I could also convert the shards to keyframed objects and have motion blur⌠HmmmmâŚ
You could use a Dynamic Paint Canvas after the FM with low displacement settings. Optionally you also could use autohide and make the Dynamic Paint Brush into a group, and assign it to the Autohide filter group in the FM. But note, the autohide filtering uses only a radius (depending on the objects size it was i think) around the filter objects, so to have certain shapes you might need more of the filter object. If you dont need autohide (e.g. you cant look through that ice block) you can omit it and use the Dynamic Paint displacement only.
Here is a small example blend of how it might look like:
ice_crack.blend (359 KB)
Move the green cube (its a sphere with bounds only displayed) around and see the cracks appearing. if you do Alt A before, and then move the cube the cracks will also remain as long as the animation runs (this is from Dynamic Paint)
Edit: hmm it might be better to omit autohide here, since its starts to flicker when DP Displacement is used and the animation runs.
Edit 2: in this file, you need to set autohide to 0 again, it looks like its 0.00000 but there it is 0.000001 here
The Autohide filter group is the one! Absolutely perfect!
Okay, now Iâm hoping this will be my very last question - where the cracks are visible it seems like they are jittering slightly. I have the object set to triggered, and enable deactivation, and start deactivated, but still the cracks are flickering.
Any ideas?
(This is with autohide and everything switched off for nowâŚ)
Ohhh, hang on, might have just been caused by my camera clip distance being set very low⌠Having a quick test render nowâŚ
Nope, not that⌠Autohide is off⌠I think itâs probably more of a blender physics question rather than specifically to so with the fracture build.
I have the ice resting on a plane, tried making sure the bottom verts are at 0, and the plane is at 0, then tried raising the ice up a fraction to get it to drop and hopefully settle (with enable de-activation) but to no avail.
Looking at the path fracture video on the FM site, I really need to make it so the ice block doesnât initially drop due to gravity, but even playing about with âtriggeredâ, start deactivated etcâ it still drops by defaultâŚ
EDIT: just had to free and then rebake. Still flickery thoughâŚ