metaball modeling

[deecue]

so i've been messing around with the idea to model my 'character' in metaballs..

it came to me the other day when i thought of how people in the history of art used circles, ellipsoids, and spheres to draw and sculpt things. (i.e. traditional 2d animators makes their characters based off them, michelangelo as well as others use to use them to construct the muscles of a body, sculpturs use them as a unit of measure for a rough model)

so basically i am using metaballs with different shapes, sizes, and weights to get my rough model. then i use a convertmeta sop to convert it to poly's at a low level of detail. i then use the poly's to get more rough detail in. i subdivide a little bit. add detail with the new create subd's. repeat if necessary. and finally subdivide again for a finished smooth model. it seems so far to be a very fast way of working and i kind of like it. the only thing it really is good for though is more organic stuff. i.e. you couldn't model a bridge very well this way.

so yea, no one around here has ever heard of modeling this way so before i get into it too much, i figured i'd ask around and see if anyone has attempted this method before and would like to share their dislikes/likes and benefits/drawbacks to it.

so far i have only encountered something that maybe someone has a solution too (but i think it's just the way it is): so, i have my metaball network merged and converted, edited, subdivided, edited, and subdivided. if i go back to one of my original metaballs and just rotate it in the slightest, my point numbers go crazy. i actually completely expected this to happen but was wondering if anyone knew a work around.

hopefully this inspires someone else to try the method if they had not heard of it before either. but im hoping to find people that have as well. and also a work around to the point numbers would be sweeeet.

so yea, thanks for listening to the long post everyone ,

dave q

[meshsmooth]

on my travels i forund this

http://www.accad.ohio-state.edu/~mlewis/AED/Figures/

[athomas]

Deecue,

Actually Realise Studio have used metaball modelling quite a bit, we also used it on the last commercial to for BMW.

The main reason for using metaball modelling is that you can produce good fluid effects with your final model, since you get good control over the behaviour of the metaballs.

Oh, also you are able to create hardedged surfaces with it just adjust your parameters (not in front of Houdini at the moment) but I believe their are the bottom ones and your weight, but doing this you will lose the organic feel.

[MG]

MIRALab used to have metaball and "virtual human"-related things on their site, but I had no luck finding it again.

I found this instead:

http://www.tel.fer.hr/users/ipandzic/frame...reativity97.pdf

[deecue]

Thanks for the replies. Great links too.

athomas: were you talking about the xy and z component in combination with it's weight? They give off a starlike or boxlike shape to the metaball which has been nice. But sometimes gets a little wierded out when converted and sub-d'd in my past couple tests.

I'm still trying to figure out a way to be able to have my surface converted and edited and still be able to go back to my metaball's to adjust them with out the pt numbers getting all out of wack and screwing up the edits. will see if anything comes to mind.

Also, here's a head model of the full grown fetus i am working on. not great or detailed at the moment, but thought it was a good example of metaballs in action with how fast you can work with them. whole model took ~3.5 hours. comments, as always, are welcome.

thanks,

dave q

p.s. im kinda new to this whole posting thing... do people get annoyed when the same thread is started over at sidefx and here at the same time? i didn't know if that was kind of taboo in the houdini posting world.

[Mcronin]

I've tried modeling with metaballs in Houdini. I found them great for making muscles, unfortunately that was pre-Inflate SOP, and the results with bulge and ray... weren't so good. They would throw errant point displacements everywhere. I tried modeling a human, but it was tedious, and when I converted it to a mesh I had alot of cleaning to do, so I've given them up for most modeling tasks, but they are a hell of a lot of fun to play with, especially with particles.

BTW, I think cross posting is OK. Suprisingly there's alot of people that don't seem to post on both boards. If you post at SESI, you're likely to hear from people like Ben from vislab, David Ridner, John Coldrick, and some the developers, who don't seem to pop here too often.