#Shrink Wrap
6 messages in this thread
When working with SoftImage, I used a third-party package that would take an
object, such as a flat grid mesh, and use it to wrap around a second object
creating a copy of the second object, only this first object may have different
vetices, properties, etc., and was mostly used to create morphs. I am familiar
with skin.axp, and I have tried it on a project I am working on now, but I have
not been successful in creating what I want. Maybe someone can help with
suggestions.
I am morphing an object from a blob to a complex computer monitor. I have used
spherify.pxp to make a sphere of the monitor, then 2D scaled the sphere's
vertices down to resemble a mound. I then moved various vertices around as to
create a non-symetrical blob. The blob at this point is very choppy and not
smooth. I assumed I could use skin.axp to create a smooth shell over the blob,
and soon found that there is a lot more involved to morphing with skin.axp. My
blob (template object) was not valid so I used slice.pxp to fix this problem.
Everything went well after that except that skin.axp is using every vertex on
the blob to position itself, which is not good in this case because I still get
a choppy-like effect, only smoother. I am seeking a look that resembles
spilled water or paint on a table.. not perfectly round, but curvy. I was
informed that if I mess with the object on the object level, it would mess up
the morph process, therefore deform.pxp is out of the question unless I can
deform the vertices only. Is there an IPAS routine that will take an object
and shrinkwrap it around another object with varying strengths, such as how
tight or how loose it wraps? This would be an easy fix for my problem. Thanks
for any help.
James Franssen
Schreiber makes an IPAS called DRAPE wich allows you to "alter the shape of one
mesh to conform to the shape of another mesh." I havent used it, but it's
available from NW Tech Systems (206 641-3282) for about $300. Hope this helps.
-Mitch
i talked to schreiber yesterday and was informed that DRAPE is still not ready
to ship. they think it may not ever be complete. they are crediting/refunding
for those of us who hve it on back order.
James,
First of all, I have used programs with patch "shrinkwrap" functions as well,
and also would like to see that function in 3DS. Secondly, I believe you are
misunderstanding SKIN.axp. If you have ever used a spline modeler, you are no
doubt familiar with creating lattices (hulls) to define/control the curves.
With SKIN.axp, you use 3DS's native polygon tools to construct/edit a lattice
for spline patches that you will never see in wireframe. The spline-fit
functions happen in the renderer and ultimately create a bunch of triangles to
render. There are rescrictions wrt building the lattices, though. In general,
the vertices must be ordered in a certain way, and lofting with optimization &
weld OFF will produce this ordering correctly. You can use some other
primitives as per the doc's with vertex modifications. Slice.axp is NOT
intended to make ANY OBJECT "skinnable".
Your experiments with Skin.axp are probably "rough" due to using too high a
step level on your shapes and/or path in the lofter. While working in 3DS's
NATIVE modeling system, you likely want/need the step level to be higher to
produce perimeter smoothness in the object. But with Skin.axp, the idea is to
use a minimum of control points for the lattice. With splines (especially
B-Splines), you achieve maximum smoothness via minimum control vertices. A
simple 8-vertice cube with 0 step setting will produce a capped cylinder – very
smooth. After you have lofted your lattice(s), you can manipulate them at any
level – no problem – just don't delete any vertices in the process. Check out
my Cowboy head Skin model on the disk – it is reasonably detailed & smooth, yet
only uses 680 vertices for the skull.
For your example object, deform the original properly constructed lattice
manually or with any routine that does not add/delete vertices, to create your
morph target(s). Keep in mind, using MINIMUM control vertices, your "blob" will
look rough in wireframe, but should render very smoothly. With the parameters
in the Skin dialog, you can control tension and bias for the smoothness
direction as well as resolution.
It works well. Hope this helps some.
BILL
Thanks for your clear explanation of this process!
Connie
You're welcome, Connie.
BILL