growing a wireframe

[mattmos]

Hi all,

I can create a wireframe via strands, and grow strands over a mesh surface, but I can't seem to figure out how to grow a wireframe. I've been experimenting with the emTools tagging points but how can I set up strands to draw to the tagged points as they are activated (and along edges only)?

Appreciate any pointers or nudges in the right direction

[Tekano]

sorry Matt I dont get what you mean by wireframe - its a curve a strand or a gemetry or a...?

[mattmos]

Hi Rob, sorry I'll try to be a bit clearer. I'd like to run particles along the edges of a mesh creating strand trails behind which build what looks like a wireframe of a mesh. So a bit like abStrandwire but growing from one side of the object to the other if you see what I mean.

Eric has some tools to make particles run parallel to edges but not stick strictly to the edges.

[Tekano]

oh I see, so in this case - wireframe = strand . not sure if this will help but here is a quick adapted 'make wireframe' compound from back in the day. think it was called atomic or something by Helge Mathee. create a pointcloud and just plug your geometry in. think it actually makes a particle per edge and stretches it along the edges but might give some pointers on how to do it with strands.

[Helli]

Creating a strand for every edge is easy.
Letting those strands grow over the geometry from one point is a whole different thing.

[Bullit]

Here is another scene: http://softimage.ru/forums/index.php?showtopic=8593

[Mathaeus]

I'd like to run particles along the edges of a mesh creating strand trails behind which build what looks like a wireframe of a mesh. So a bit like abStrandwire but growing from one side of the object to the other if you see what I mean.

Just a few simple tricks:
- if everything is generated at once, using un-simulated ICE tree ( like AB strandWire). Instead of growing, you can just 'un-delete'. At the end of ICE tree ( to prevent something unwanted during generation process), just delete points by some criteria. Animated or simulated weightmap, closest distance to some surface, UV position (let's say, if "V" of UV at emit location is smaller than Y position of some animated null, point is deleted), whatever.
- as Helli said, this is easy to do with points, but not so easy with strands. Strand array can't have "empty" spaces - so it would be good idea to generate something like Ab strand wire, but using cloned points instead of strand segments.
Ab Strand Wire or Helge's "atomic" compound, they creating clones, according to number of neighboring edges, for each point. Next step are clones/ strands, extending to half of edge. So, one "unit" looks like small star.

[Matic]

Time is tight, so i cant work up an example today, but...

Strands are all associated with a particle. So, one aspect of your challenge is to create a progressive growth of particles at vertices... This has been widely done in a number of ways, there should be a couple of examples on my blog and elsewhere. Then, when a particle is formed at a vertex, you need to "grow" your strand down the edges to neighboring vertices. Again, this is well covered elsewhere, for instance check out polynoid guru Fabian Pross's blog "Monophyl."

Also some digging on my blog should reveal compounds which create linear strands to a pointPosition, or which build position arrays which can be used for same... You can make such a strand "grow" by either culling "n" points off the end of a strand and animating the number culled or by simply making your "target" endpoint the result of a linear interpolation between self pointPosition and neighboring vertex pointPosition, and animating the blend. You can alternatively simply multiply the vector by a scalar to increase/decrease its length which is how I created sketch-like "construction lines" in the video below.

This is a broad description I know, but this kind of approach works. Here is a viewport capture of some lookdev that took about 4 hours start to finish to make and which could have been (but wasnt) greatly extended from there... http://www.vimeo.com/30688549 ...in this case the mesh was reasonably dense, so I also animated individual strand opacities via underlying weight maps (instead of creating particles over time, creating them all at once and then revealing them over time. If you are using Eric's "tagging," perhaps use the tags to determine opacity?)

Sorry for the rushed explanation, time is short, but give it a whirl I've done it in the past and it wasn't hard at all. Cheers

(Also cloud-guru tekano did some very nice lookdev on a job we briefly shared where he used some of Eric's tools to make strand trails grow along edges, for a less mechanical, more organic look which was pretty cool, check his Vimeo posts he may have an example up?)

[mattmos]

Hi guys,
thanks for the ideas and suggestions, I really appreciate having a bit of your brain time! The direction for the pitch has gone from a 2 second effect to a 10 frame effect, so it is much more suited to the non-simulated un-deleting particles option for now, though I'd like to try to figure out how to get the original effect and will keep working on those suggestions as I'm sure it will come up again sometime.
Cheers