#SKINNING prefixed objs
9 messages in this thread
I am having problems skinning objects that use the "Prefix" option. To test it,
do the following:
1) Create a cylinder(6 sides, 1 segment) with the following:
Base: 0,0,0
Radius: 20
Height: 10
Name: obj01
2) Create another cylinder, this time, much longer than the first:
Base: 0,50,0
Radius: 20
Height: 300 (much larger)
Name: obj02
3) From the top viewport select the middle vertices of the cylinder and then
delete them.
4) Assign SKIN to the "obj01" object and select "Catmull" and "Use Prefix".
5) Render the object. You will see that rather than the skinned object being
long it is instead short.
It appears that skin is using only using the first cross-section of the second
object "obj02" and not the last cross-section. If you copy the "obj02" object
and assign it a wire texture you can see that the last cross-section in the
"obj02" object isn't being used.
Also if I make "obj02" an element of the first object "obj01" so that I have
single object and then select "Single Object" in the SKIN dialog box, the
object is skinned correctly, i.e. a long slender pipe is rendered.
Could you please help me out since this is very urgent. Thanks.
BTW If I create two objects one named "ralph" and "ralph02" and then open the
attributes dialog box to change the name for the first object to "ralph01" AND
at the same time I assign SKIN to the object and then use "Use Prefix" it
complains that there aren't enough cross-sections. It is simply a case of
checking if the name has been changed in the dialog box "Object Name: " field
rather than checking the object database for the name since it has just been
changed but not yet commited to the database. No big deal, but something you
might want to think about.
David "Skinned alive" Gould
From your description, it sounds like you're using the "prefix" option with two
completely different objects instead of with sliced cross-sections of one
object.
I get this impression because you said to make two cylinders, called obj01 and
obj02, and then select obj01, apply skin with the obj prefix. In this case,
it'll try to skin between obj01 and obj02. If you really want more than two
cross-sections in a skinned object, just loft it (or set the creation
parameters) with more than 2 cross-sections.
If I'm misunderstanding exactly what you're getting at, you'll have to simplify
this to a simple case for me and zip up the .prj file with an explanation, and
I'll try to get to it this weekend.
– G
Gary: <sounds like you're using the "prefix" option with two completely
different objects> That's how I read David's note also. So, I'll just chime in
and add a thought: In the documentation there is some discussion as to what
shapes slice better than others. David, you'll see that meshes can be kept very
simple, and given sufficent levels on the path, slice&dice very well. The
skinning paramenters can be adjusted to "compensate" for lack of mesh detail.
Also, check out leaving the start cap and end cap off. [hey, while I'm at it,
might as well say how much fun slicing, skinning and animating the results
are… want an amorphous globule of transparent noisy liquid splaterring? No
problem… under an hour and animated] Jeffrey (it's getting better all the
time) L
<<hey, while I'm at it, might as well say how much fun slicing, skinning and
animating the results are… want an amorphous globule of transparent noisy
liquid splaterring? No problem… under an hour and animated>>
Sounds like the state of the kitchen after I make scones <g> I'd be interested
in seeing some of your "globulous objects", any change of you uploading a few?
David "Looks aweful but it tastes great!" Gould
David <globulous objects> They are really no big deal. You can get one going in
no time at all. Just slice an oblong lofted, rather simple shape. Assign it
40-50 transp with a high specular Luminance and very shiny so that the spec
highlights will really glisten. Throw a low % NOISE2.SXP, head off to the
keyframer and give the shapes hierarchy. You can size individual slices and
turn off the size hierarchy in Link Info. It is very easy to make an object
appear liquid, and effected by secondary forces like wind or gravity. Hot
butter running off one of those aweful looking scones would not be difficult,
but you would have to forward a scratch and sniff sample to really get to your
client. Jeffrey
<<From your description, it sounds like you're using the "prefix" option with
two completely different objects instead of with sliced cross-sections of one
object.>>
This is exactly right. I'm aware that you can "slice" a lofted object but I
also found that if I create cylinders with 5 sides(pentagon) and then deleted
the "core" vertices I could achieve the same effect of the slice routine.
The reason I use the "Prefix" option is so that I can have separate
cross-section objects that I can move and animate individually. SKIN will then
create a smooth surface between the animated template objects not matter where
they are located. Sort of like a serpent.
I found what I was looking for on Page 34 under Note: . It was regarding the
use of the different cross sections in the skinned object. I see now that it
uses the bottom cross-section of the lowest slice and the top cross section of
all the slices above.
This explains why I when I scale a "slice" along it's length that the skinned
surface doesn't run through both the bottom vertices and top vertices but
instead typically only the top vertices of the cross section are used as
control points.
Thanks.
David "Note:" Gould
David,
PMJI, but I believe you are missing the point of "by Prefix". In order to work,
the objects or slices must be named with the same prefix, that is:
Obj01, Obj02, Obj03 must be identical wrt vertex count, and only contain 2 sets
of "boundary" vertices (the circle of vertices at the ends of a cylinder), and
should not contain a co-planar cap performed by 3DS (OK for Skin.axp to cap the
ends).
In your example, it would be better if you defined a circle in the Shaper,
Lofted without caps or Welding, and with Mapping ON. Then, you could define
segments for the cylinder by adding vertices to your Lofter path, or you could
create multiple "slices" as needed to dump into the Keyframer.
You ARE rendering By Prefix Slices from the Keyframer, right ?
WRT to the name-changing problem, sometimes if you change things after Skin is
set up, you just need to enter the Skin dialog, then exit to refresh.
BILL
<<In your example, it would be better if you defined a circle in the Shaper,
Lofted without caps or Welding, and with Mapping ON.>>
Doesn't SKIN ignore the mapping applied and use it's own unit length mapping?
<<You ARE rendering By Prefix Slices from the Keyframer, right ?>>
I can render it in both the 3D Editor and the Keyframer without problems.
Thanks.
David "Normalized human map" Gould