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View Full Version : Yikes, Hypervoxels can't do this?



Hieron
04-14-2009, 04:28 PM
Had this easy peasy idea in my mind and set about creating it.
What I need is some idea of cells (organic) dividing from starting of 1, to say 32.

I could create a random point cloud of vertices at nice distances and instance polygonal cells (spheres mostly) over them. And make morph maps by pulling in the vertices untill I end up with all 32 vertices on top of eachother making it look as 1 cell.

Now alot of issues with that idea.. can't do them transparant, polygon intersections etc

So I decided to take Hypervoxels for an easy spin, instead of instancing polys. So some hypervoxels on vertices came to: 72428 (wip :))

Check.

But yikes.. when the vertices and thus the cells are pulled inward, they keep volume, and thus in the 1 cell origin I end up with some big fat cell... and in between the cells that need splitting still are obviously thicker than the rest too..

Also, for some reason, if multiple vertices are close to eachother and lead to a blended (but big) sphere, the World Coordinate Hypertexture makes no sense. In any case, I'd expect to have a nice texture as before, but it has become a smooth blob, as if all textures were not world coord and smeared out..

Anyone have got a clue if there is a way out, or perhaps a totally different way to go about it? I need these splitting cells :P (they don't need to be real close up, but I have 4x these 32 or so.. so manual is possible but not handy)


Edit: went for instanced and distorted polyspheres.It will do, even though the HV blend would have been nice to have and I still don't know why the hypertexture gets messed up if you have multiple vertices at the same spot.

bassmanjam
04-14-2009, 06:32 PM
Would metaballs worked for this? I don't konw. I haven't played with them in a while.

Sekhar
04-14-2009, 07:34 PM
Well, you could envelope so the size stays the same. The size with two balls together will be 2**1/3 of one (because the volume doubles), so you compensate for that. E.g., see attached.

SplineGod
04-14-2009, 07:56 PM
The trick to doing this is to tackle each event at a time. Generally I start with the biggest then and work down to the details.
Heres an example of something I did that was similar. Ive also done another one awhile ago tha had the cells dividing. Ill see if I can dig that up.
http://www.vfxcast.com/media/1321/Staph-bacteria-colony/

Hieron
04-15-2009, 02:23 PM
Would metaballs worked for this? I don't konw. I haven't played with them in a while.

Actually, don't know.. I tried using them once of twice, but usually gave up. Not 100% sure what my main issue was.. but I have no fond memories :)



Well, you could envelope so the size stays the same. The size with two balls together will be 2**1/3 of one (because the volume doubles), so you compensate for that. E.g., see attached.

Yeah, actually I tried using that. But from your example, now try to do the next step :P Then it becomes trickier. You'll have single vertices, some that still need dividing at a later stage etc... It works for 1 to 2 division, but not further.... I think


The trick to doing this is to tackle each event at a time. Generally I start with the biggest then and work down to the details.
Heres an example of something I did that was similar. Ive also done another one awhile ago tha had the cells dividing. Ill see if I can dig that up.
http://www.vfxcast.com/media/1321/Staph-bacteria-colony/


Not sure what you mean with doing the events one at a time.. The resizing of the spheres is tricky when using the morph map.. it will have various amounts of points per blob at any point of time except the final shot..

Nice animation btw, as you also say it doesn't show division, but nice nonetheless. How did you get them to pop up over time? Weight map?

I'd be very happy to see your other animation that shows dividing cells :) So if you got the time to dig it up, please do :P


Thanks for the help guys, it's appreciated!


ps:does any of you know why hypertexture goes wrong if you have a 2+ vertex HV sphere?

SplineGod
04-15-2009, 04:07 PM
The bacteria colony is a single object. I used a single endomorph driven by a single texture. Ive used this technique with LW forever. Its a fast/easy technique. The cell division can be done as a 2nd endomorph layer.

Hieron
04-15-2009, 05:46 PM
hmm.. not entirely sure how that would work..

Can you elaborate?

Sekhar
04-16-2009, 07:24 AM
Yeah, actually I tried using that. But from your example, now try to do the next step :P Then it becomes trickier. You'll have single vertices, some that still need dividing at a later stage etc... It works for 1 to 2 division, but not further.... I think

You just need to keep doing the same thing with a pair of HVs for each split. Say A splits to create B and C and you want C to create D and E. Create B/C like with the pair example, parenting C to B - except, also envelope C to go to size 0 at the end of the split. Then create a new pair (D and E parented to D) and parent them to C. Then after first split, C disappears and gets "replaced" by the new pair D/E. Quite simple because you just need to create the B/C pair once and keep copying and parenting as needed. Start with B/C at origin and remember to disable parent in place. I tried, and it works.

Hieron
04-16-2009, 02:05 PM
You are right about that Sekhar... and it may work nicely.. but it is quite some work to set up (I need quite alot, like 150 final cells) and if I need to tweak it, you got a huge set of clones that need reworking right?
So it would work, but take a hefty amount of time and be quite tricky to tweak later on. (and you know that client is going to want some minor tweaks...)

Thanks though.. would be nice to try the thing when I got some spare time.. this specific topic of dividing cells is quite a frequent request, so maybe some decent time into a good base system is nice.
But it feels tricky to tweak once made..