Smashing a flying object

hey blender heads

ok wonder if anyone can help please! been trying all day and now banging my head against the wall (but its not smashing…)

this was easy to do in 2.79 with fracture modifier but cannot figure out how to do it in 2.83

it sounds simple, a box is thrown and i want it to explode in mid air, as my box has a couple hundred pieces, i cannot go in and click animate in the physics tab for each individual shard, and trying to use the copy from active is painstaking.

is there any way to achieve this in 2.83 please? it should be simple, animate my object then keyframe when i want the fracture to start…

i also was gonna do a ‘cowboy’ switch, have a broke box already in place and make it invisible then when the OG box gets to the required position, make that invisible and my fractured object become visible and start the sim but no way to make it invisible.
i tried visibility in objects properties, but cannot do it for a collection and also the eye and render icon wont let me keyframe in outliner.

thank you for any help :slight_smile:

Hi there,
This is not an ideal solution and I’m sure there are better ways to do it, but depending on what you need it could work.
You can add the “quick explode” under Object>Quick Effects and then set the start frame of the particle emitter to when you want it to explode.
This will make the box explode like a piece of paper. You could then add a solidify modifier to get chunks but the result still isn’t the greatest. In one of my examples I added a displace modifier with 0 strength and just increased it after the cube explodes. Playing around with different modifiers will hopefully give you a usable result.
Also there is the problem of motion, as the chunks will fall straight down after they explode. You could place a force field in the scene which would move the particles in the desired direction after the explosion, but it will take a lot of tweaking to get a nice result. Alternatively you could give the cube a rigid body and try manipulating it using force fields. This will give you less control over the overall movement of the cube but the explosion looks nicer in my opinion. One other thing about the second method, I believe there is a bug in Blender right now as the particles will fly a lot in front of the object after it explodes. This issue is apparently random as sometimes it happened and sometimes not. To counter it I changed the physics type of the particles to fluid but there is still some weird movement after the explosion.

Here are the example files I quickly put together:
Example.blend (814.3 KB)
Example1.blend (852.8 KB)

Anyways, hope this was of some help to you and I wish you luck!

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If you know how to do it with the fracture modifier I would do it with the fracture modifier.
Create the fracture simulation in 2.79 and then export it to 2.83. You can export it to 2.83 either with mesh cache or alembic. If your sim does not change vertex count ( i.e. if you do not use the weld mesh function of the fracture modifier ) you can use mesh cache which in my experience is a lot faster.
If your cache does change vertex count then use alembic.

There is a tutorial from the developers of fracture modifier that shows how to export and import it with alembic on their web site. With mesh cache you do it pretty much the same way.

You can of course also export and import any particles you created with the fracture modifier by simply using a disk cache.

That is weird because the render icon is keyframable in the outliner. If you want to animate the visiblity in the viewport you have to use “disable in viewports” which is the monitor icon and not the eye icon. It is true that you can not animate the collection visibilit, though.

1 Like

Thank you so much for taking the time to reply. Yeah I looked briefly yesterday at quick explode but didn’t try the solidify modifier so will give that a bash today.
Thanks again :slightly_smiling_face:

Thank you very much. Yeah I went into 2.79 yesterday but was weird as so used to 2.8 now.
Thanks for the alembic suggestion, will give that a try.

Hope they bring FM soon to 2.83.

:slightly_smiling_face:

Went with the quick explode for now as it was quick and dirty but kinda did the job. Thanks for the replies guys.

Wish cell fracture had at least a function to start it on a certain frame.