Cineversity

On this archaeology show I’m working on I have to create a fragment of an old piece of pottery (a pitcher) that matches a piece of video, then fly that back from the camera and have the rest of the pitcher assemble from 5-10 pieces into a complete object.  Once I’ve modeled the jar to match the reference images what’s the most efficient way to cut it up for animation?

I’ve played around with Explosion FX, using selection tags to define the pieces, but using it to generate depth doesn’t create an accurate lip.

Is there any (relatively easy) way to slice through a thin-walled object such as a jar so that when I separate the pieces the edges of the cuts will be solid?  I also play around a bit using the boolean tools, and that looked like a nightmare.

Nitro Blast might work, though there might be limitations as to how I can surface my pieces.

Thanks.

Shawn Marshall
Marshall Arts Motion Graphics

Hi Shawn,

You might find a tutorial with such a theme here:

http://www.cineversity.com/vidplaytut/shattering_an_object_with_modynamics_part_1

The problem with Boole is of course based on several circumstances. The smoothness of a pitcher is based on Phong-Shading, this becomes more obvious the larger the mesh is. Any roundish surface that becomes a cut e.g., based on a boole, looses the continuations of the phong.

A plug in like this http://www.plugins4cinema4d.com/rboole.html might solve the surface problems (not used so far, but people had good results with it. The problem is then given with the dynamic, as the “invisible” object parts are active for that process. Which might be solvable with many tricks….

You might check out how far the “Connect Object” might help here to melt/weld these chances . Here I see the most success if time is an concern.

Besides that, you might render the scene with a complete pitcher, and then while it breaks a parts. Then you need a traveling mask to merge both. The un-broken one might need some movement. Works certainly not for slow-motion… and is as well as other ideas not a push button solution.

A did a little solution with switching the object, when the “Ghost” option was available: http://old.cineversity.com/forum/forum_posts.asp?TID=2720&PN=1  Enjoy!

All the best

Sassi

Hi:

Thanks for the quick reply.  That’s an informative tutorial; I think that boolean approach to cut it up will work.  I can probably mitigate or hide the phong issues since the pottery is old and bumpy.

Cheers.

Shawn

Hey Shawn,

Nice that this works for you.

Hehe, old and bumpy, that will certainly create a much more believable situation. To keep one pitcher in one piece as copy, might help to patch perhaps some areas later in post—if needed at all.

Good luck with the project

Sassi