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View Full Version : How to build a perfect subpatch bowl like hemi-sphere?



desinger
11-04-2004, 11:58 AM
Hello all lightwave3D expert,

I wanted to build a perfectly subpatch bowl like hemi-sphere. I find that problem is the upper O'ring shape cannot subpatch perfectly with lower hemi-sphere. You can see the edges of upper O'ring is straight not curve. My English is poor so I cannot input more. Thanks for any suggestion. :D

http://member.hkbn.net/~prodesigner/sphere.jpg

hrgiger
11-04-2004, 12:17 PM
You mean something like what I'm posting below? I'm not sure what you mean about the edge of the o-ring being straight...

mattclary
11-04-2004, 12:25 PM
OK, Steve, so how do you make a box!? ;)

Hervé
11-04-2004, 12:35 PM
well I'd be interested for the cone... :D

Silkrooster
11-04-2004, 03:17 PM
desinger,
A couple of ways I can think of to create a bowl that can be sub'd. First is to make a ball, select half of it, delete that half so you only see a half a sphere. Select the remaining half, copy it, flip it and reduce the size to fit. Now you select points on top and create your new polys for the top edge (Make sure you only select four points at a time to make quad polys).
Second way is just create a profile of the side of the bowl and use the lathe tool.
Silk

meatycheesyboy
11-04-2004, 03:28 PM
Or if you want it to be all quads, make a box, subdivide it a few times, sphereize it then follow silkrooster's directions above.

SplineGod
11-04-2004, 11:51 PM
make a box, Hit the tab key, hit shift + d and metaform it it a couple of times.
Select half the sphere and delete it. Select the hemisphere, hit ctrl + c to copy it. Hit f to flip the polys and smooth shift the whole hemisphere slightly. Hit ctrl + v to paste the original hemisphere. hit m to merge the points. :)

Darth Mole
11-05-2004, 04:19 AM
Could you not use Blochi's Thickener to create the depth, then knife along its flat 'top' to create a sharp Sub-D edge?

stib
11-05-2004, 06:31 AM
make a box: one poly per side is all you need.
select the uppermost face.
bevel with a little inset but no displacement, to create the thickness of the bowl.
without deselecting that polygon bevel again with displacement to create the inside of the bowl.
you now have a box, open at the top with inside and outside faces
tab key to subpatch
QED.
it may be a bit rounded at the top. Bandsaw pro will help: select a couple of the outer sides and use bandsaw to make a slice close to the top. Repeat with the inside. Or you could adjust the subpatch weight of the vertices around the top if fiddling with weight maps is your thing.
You can of course start with a cylinder instead of a box, or you might find that you need to turn up the subpatch divisions to get a smoothly curved edge in layout. But starting from a box demonstrates how easy it is to model with subpatches, and it also leaves you with less polys to have to edit.

11-05-2004, 07:23 AM
desinger,
the answer to your original question is probably that the model you have created has polygons of more than 4 sides which cannot subpatch.
Your model looks as if you used boolian subtract to cut a sphere in half, leaving the cut surface as a single poly with as many sides as the sphere had, when you cut another half sphere out of that to make your bowl the 'ring' edge became a single poly with twice as many sides.

For a beginer the simplest thing to do is to work out a way to replace that ring poly with a series of 4 side polys.

hint - if you stareted off with your spheres centred on 0,0,0 it would be easy to delete all except one segment of your bowl, add a 4 sided pole at the top, and then array in a circle and merge points.

desinger
11-05-2004, 11:43 AM
make a box, Hit the tab key, hit shift + d and metaform it it a couple of times.
Select half the sphere and delete it. Select the hemisphere, hit ctrl + c to copy it. Hit f to flip the polys and smooth shift the whole hemisphere slightly. Hit ctrl + v to paste the original hemisphere. hit m to merge the points. :)

Thanks, SplineGod. I followed your instructions to build the bowl like hemisphere but the top of it (ring shape) is curve surface. I wanted the top (ring shape) is flat. Then, I can mirror a upper bowl like hemisphere to become a hollow sphere. It formed by two hemispheres. :)

desinger
11-05-2004, 11:58 AM
You mean something like what I'm posting below? I'm not sure what you mean about the edge of the o-ring being straight...

Yes, especially the top ring shape (concentric circle) is flat. Can it be subpatch? My bowl hemisphere ring shape is flat because it consisted with weight map. But the two concentirc circles (edges of ring shape) are formed by many straight line due to each line connected with below quad polygon. :(

desinger
11-05-2004, 12:05 PM
Thanks for all replied. I think main problem is the ring shape (two concentric circles at top) must "retained flat" after subpatch with hemisphere below.

mattclary
11-05-2004, 07:19 PM
Is this what you're looking for?

SplineGod
11-05-2004, 07:52 PM
Select two polys on the ring and either use bandsaw or select loop to select those polys and give them a very slight smooth shift, super shift or subpatch weighting. :)

desinger
11-06-2004, 08:35 AM
Is this what you're looking for?

exactly :eek: , how to do it :confused: Million Thanks :D

desinger
11-06-2004, 08:42 AM
Select two polys on the ring and either use bandsaw or select loop to select those polys and give them a very slight smooth shift, super shift or subpatch weighting. :)

Thank you very much :D

mattclary
11-06-2004, 11:20 AM
I created a sphere, deleted the upper half, used Blochi's "Thickener" plugin (search flay.com) to give it thickness. Then I made two "knife" cuts reallt close to the top, then hit the tab key. Bandswa will also work as stated by Splinegod. I did the same thing Darth Mole suggested.

Personally, why the heck are you subpatching this anyway? When creating the sphere, just up the sides and segments then turn on smoothing. Still use thickener.

Non-subpatched bowl:

hrgiger
11-06-2004, 05:48 PM
Didn't I just say that?

SplineGod
11-06-2004, 06:27 PM
Thanks Matt,
I manually did what thickener does but both work out. :)

Desinger,
Youre welcome :)

mattclary
11-06-2004, 08:21 PM
Didn't I just say that?

Not in Newby-ies. ;)

Silkrooster
11-07-2004, 09:09 PM
This is what the wires would look like using a half a ball like I suggested before. One note though, earlier I left out using bandsaw on the rim to keep it flat. I guess that is what happens when you post before experimenting. :rolleyes:
Silk

Silkrooster
11-07-2004, 09:11 PM
Now I think of it the bowl would have looked even better if I had rotated the ball so the poles were on top and bottom. Oh well.
Silk

BeeVee
11-08-2004, 02:36 AM
This tutorial has been on NewTek's site for two years...

http://www.newtek.com/products/lightwave/tutorials/modeling/modeling/bowl.html

B

theo
11-08-2004, 05:34 AM
Why MAKE one? Just go buy one.....I think Walmarts has bowls.

desinger
11-08-2004, 06:27 AM
This tutorial has been on NewTek's site for two years...

http://www.newtek.com/products/lightwave/tutorials/modeling/modeling/bowl.html

B

Hmm... , I didn't want a bowl... , just wanted a PERFECT hollow hemisphere :p