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Columbo24
12-20-2014, 09:07 PM
I'm doing Adam Gibsons Dinosaur tutorial. I'm starting with the head. I follow the instructions and hit tab and I get bizarre results. First I create a flat polygon. I select an edge and hit E then T and make geometry around the head. I have 8 4-sided ploys in the shape of a dinosaurs head. Next I extrude the shape. When I hit tab it either breaks into parts or flattens out on the side. I removed one side of the polygons and noticed extra geometry that is inside causing the problem(I think). One time I selected all the polygons and extruded, the other I didn't select anything and extruded. Both times there were extra geometry inside.One time the statistic panel showed two sided polys. Does extruding multiple polys cause extra geometry and cause problems in suD. In the tutorial he gets a nice mesh. I'm not. Any ideas? Thanks.
Bill

ernpchan
12-20-2014, 10:28 PM
Yeah the interior polygons are creating a problem. Just delete them. If you have polygons sitting on top of each other you could use the merge points command to merge redundant points and the unify to collapse polygons that are directly sitting on top of each other.

Sensei
12-20-2014, 10:37 PM
On top of head we can see 5 point polygon (n-gon). That won't work with LW v9.3.1 definitely.
If you don't want to create such n-gons grab plugin EasySplit http://easysplit.trueart.pl
While making cut, it has option that will make sure you're never creating geometry that's causing problem with traditional sub-patches (Fix n-gons option).
Otherwise you have to make sure by yourself. It's annoying because of popping up warning requester, while pressing tab to switch to sub-patches.


the other I didn't select anything and extruded.

Then you created a lot of extra, not needed geometry..
Make quad in empty layer.
And then extrude it, and see what happens..

While working with half-ready geometry, you must select polygons to tell which part of object you want to affect..

Not selecting anything = selecting everything.

djwaterman
12-20-2014, 10:54 PM
Yes, you created extra geometry somehow and that is the result. It's always human error, because you are learning you will probably do this a lot, some combination of mouse clicks or something that only you can figure out. Do the extruding steps in slow motion and get used to the steps so you don't double up on them with out realizing.

Columbo24
12-20-2014, 11:27 PM
Thanks everyone
i was extremely careful w/my mouse clicks as per the advice and no extra geometry was created. Huge helpful hint.
Bill

Surrealist.
12-22-2014, 10:07 AM
Yeah extrude can get you also if you forget to undo far enough back. You might say extrude and then move and undo back to the place you started, but it is where you first extruded and the mesh is still there duplicated but doubled up in the same place. One more undo gets rid of the extra mesh. One way to check this is to use the move tool again, see if you are moving the original geometry or an extruded part. Unfortunately there is no undo for selection (as far as I know even with current version) so be careful not to deselect before you know you do not have doubled up geometry.

Nicolas Jordan
12-22-2014, 10:49 AM
One time I selected all the polygons and extruded, the other I didn't select anything and extruded. Both times there were extra geometry inside.One time the statistic panel showed two sided polys. Does extruding multiple polys cause extra geometry and cause problems in suD.
Bill

I would suggest using the "extend" command instead of extrude. It should work much better for this kind of modeling.

Skonk
12-22-2014, 01:06 PM
Short of it is, only ever use Extrude on 2d geometry.

If the object is already a 3D solid then use anything BUT extrude (extend, bevel, multibevel, multishift etc).

spherical
12-22-2014, 06:58 PM
Unfortunately there is no undo for selection (as far as I know even with current version) so be careful not to deselect before you know you do not have doubled up geometry.

AFAIK, undoing back far enough ends up with original selection being re-selected. Perhaps there are some instances where this isn't the case, but this has saved my bacon more times than I can remember.

Surrealist.
12-23-2014, 04:55 AM
Yeah that is true. What I am talking about specifically is the sequence of "e" "t" repeated any number of times. It is quite a common mistake in the heat of a modeling session to undo the "t" leaving the mesh still back on top, you might then deselect those polys and get ready to do something else before you realize you forgot to undo one more time. Once the selection is gone it won't come back and you can't check by moving the polys to see if you have double geo or not. That's just me. In the middle of the session my mind might drift and I forget if I hit undo enough times. And I always like to get the selection back to check if possible. (and of course you can not do that in LW)

Of course you can unify and merge points etc. But it is just a heads up to be aware of. I think most modelers go through a phase where they run unto double geometry a lot. And it even still happens to me at times.

djwaterman
12-23-2014, 05:34 AM
Short of it is, only ever use Extrude on 2d geometry.

If the object is already a 3D solid then use anything BUT extrude (extend, bevel, multibevel, multishift etc).

I use the 'E' key on 3D geometry a lot, there shouldn't be a problem doing so, I think you mean when you extrude a whole object because it already is in a sense extruded, so you'll get doubled up weirdness. It's okay to select groups of polygons on an object and extrude them out, perhaps that's what you mean't, but it came across like "beware the extrude tool" and I wouldn't want someone to get that impression since it is used a lot when building out geometry.