Cracking stones

[serious]

hi guys,

how do i animate a cracking stone and the part where it'll eventually break into pieces? what 's the best and most economical way of doing this? any help is very much appreciated.

thanks,

[fredc]

I assume you don't mean to shatter, but to see cracks appear then see the larger parts fall to the ground.
If this is correct, here is overview of an approach that should work.

1. Make a polymesh of your rock.

2. Decide where the large pieces occur and make individual objects out of them.

3. Use the poly tools to create sides to the pieces so they are solids.Re assemble the pieces into your original rock shape.

4. Use Shape Animations to show the cracks growing.

5. Use transformation keys to see the large pieces fall. (You could use dynamics for this portion.)

6. Use the "explode" or "kaboom" effect (see reference manual) to show smaller pieces of debris flying out of the cracks. Do several explodes, some with material set to blur, so it looks almost like dust. Note: You aren't really making explosions, just the sudden appearance of tiny fragments that fall with larger pieces.

There are probably better ways of doing this animation, but this method should work.

Hope this helps,
Urp

[serious]

thanks urp. the rock shapes are actually letters. a tablet will bounce off of it then the letter will react and have cracks on it and some small pieces removed. thanks again for the help.

[nouvelleorleans]

helo,
I saw "the making of Titan A.E", since I've gat the cd, the planet that exploded was made with "shrink wrap" in softimage 3d,,,

I can't explain how it's been worked, but I know that was something like Shrink wrap,,

I don't know whether it helps or not, but I can send you a piece of the movie about how the animators doing the "stone exploding"...

I will cut the particular part for you if you wish,,,

hope this helps

[cowsmanaut]

to use shrinkwrap you would first need to make the cluster of stones all together. they don't have to mesh completely just be close and should all be seperate objects. Do not animate them yet.. just place them.

Now, multi select them all and merge them into one object with the option to keep a copy of the orriginal seperate peices. Hide the rock bits and and shrinkwrap the large mass you created. This gives you a whole object that hasn't got any cracks in it yet.

Last little bit now. make sure your large craked peices are fitting JUST within your large whole peice. Make them all black or darkly coloured. now your texture on your asteroid or planet can be whatever but the inside bits should remain dark. Place a volumetric light in there or a few if you need more.. you should have well spaced cracks to let the light out a bit.

Now render out a bit with your whole object render out right up to the instant it should explode. save those as a seperate render. Now do a second render with your voumetric ligts and rock bits but do several frames before it explodes up to the point it does explode. Now you bring them both into something like premeir and cross disolve them so it looks like glowing cracks are apearing on your larger model and then BOOOOM!

Does this all make any sense?

[cowsmanaut]

of course this probably wouldn't help Spartacus much.. oops.

[nouvelleorleans]

yes, i think the "titan" one was done that way,,,