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aidanodr
04-25-2005, 10:14 AM
Hi Guys,

Got LW8 within the last month or so. I am having an issue with the extrusion tool.

I make a plane with 4 points from the top view, select polygon Selection Mode, then go to the MULTPLY Tab and select EXTRUDE. I then go to the back view and click above the created plane, this extrudes the four walls and top surface. I then hit the Space Bar to finish. Here is my problem: If I now rotate the perspective view at any angle I can only see the original plane [ bottom ] and the two back walls .. as I rotate around its the back walls I see. What I did try was the Surface Editor and then tick the Double Sided box, now I get a solid nontransparent object. Is this last option necessary? or can one default LW to preset a solid result when using the extrude tool?

Another thing - I notice if I now use the TAB key to get a subdivided version of the extruded plane the shape goes a bit odd, it does not change to what you expect ie a rounded, smooth "cube" - almost a sphere.

If I just draw a regular box primitive all is well - looks solid and when you TAB it you get a nice Cube Sphere shape. Whats up with the extrusion? Obviously I am doing something wrong ..

Cheers
Aidan O Driscoll

ursa
04-25-2005, 10:25 AM
probably nothing more than a negative extrusion....if you exrude a plane in the wrong direction all the polys will get flipped, so that thier surface normals point inside instead of out. Just hit the "f" key to flip them around the other way and all should be well.

aidanodr
04-25-2005, 11:03 AM
Hi Ursa,

Thanks for that it worked .. the normals were all over the place. Anyway of extruding where the normals all point out by default I wonder?

OK ... just answered that one myself. I extrude the side of the plane opposite the plane with the normal vector.

BUT, now if I bevel one of the side faces of my new extruded box, once and then twice. I now select the inner most face. I have to use the F key again to flip the normal of this face to point inwards. I then extrude this face out - all is fine. Now press the TAB key again and I notice I have two seperate objects - the original box AND a smaller extruded box. What I would like is a subdivided, smooth surface from the extruded wing up the side of the box.

Your Wisdom appreciated here. An example object to create here would be the original extruded plane is the passenger area of a spaceship and a face at either side is beveled twice - the inner resultant face is then extruded to create the wings.

Cheers
Aidan

aidanodr
04-25-2005, 11:21 AM
Hi Again,

I suppose what I am really asking - Is there any way to hop back and forward from POLY Mode [ unsubdivided ] to SUBDIVIDED Mode to see how your model is looking as you design it. Yes you may have guessed I am coming from other apps where I could hop from POLY to SDS mode and back with a button click. I dont think LW has an SDS Cage. Sub Div Surfaces are called Sub Patches ... am I Right?

Aidan

ursa
04-25-2005, 11:22 AM
I think you kind of answered your own question, If i dont misunderstand.
Intead of using the Extrude tool on the inner poly, use Bevel and it should work as you seem to want.

mouse_art
04-25-2005, 11:25 AM
I suppose what I am really asking - Is there any way to hop back and forward from POLY Mode [ unsubdivided ] to SUBDIVIDED Mode to see how your model is looking as you design it. Yes you may have guessed I am coming from other apps where I could hop from POLY to SDS mode and back with a button click. I dont think LW has an SDS Cage. Sub Div Surfaces are called Sub Patches ... am I Right?


just hit the Tab Key, it toggles the SP Mode on/off.

Dodgy
04-25-2005, 11:29 AM
Press Tab to go from subdivision surfaces to polys and back again :)

aidanodr
04-25-2005, 11:44 AM
Hi Guys,

Thanks so far. BUT they say a picture paints a thousand words .. I think thats the phrase. Have a look at these:

http://www.tidalsound.com/3dstuff/LWbefore.jpg

http://www.tidalsound.com/3dstuff/LWafter.jpg

Notice in the after Pic that the extruded wing is seperated from the original box when the TAB key is used.

Any ideas? Not subdivided enough? A quick subdiv tutorial as applied in LW maybe ...

Cheers
Aidan

aidanodr
04-25-2005, 11:51 AM
Right,

I have now noticed that after beveling the inner face and extruding it I am getting a seperate object created. I can move the wing away from the box as a seperate object. I must be creating new faces somehow ... mmmm!

Cheers
Aidan

aidanodr
04-25-2005, 12:01 PM
HOKAY,

I think Ive got it. The extrude tool seems to be the wrong tool for this, I should use the extender tool?

When I use the extrude tool on the inner post beveled face it seems to create a new object seperated from the original side box face.

I was assuming that the extrude worked the same as other apps and left the extruded face connected to the original face. Again I bow to your wisdom, maybe I am not doing this right,

Cheers
Aidan

jhopfenblatt
04-27-2005, 02:13 AM
I don't see why LW would automatically make them into 2 separate objects (it usually doesn't do that as far as I know), but I guess that you can just merge the points where the two cubes connect. If you click on one of the corners where the cubes meet (i.e. the vertices of the smaller cube), Modeler should tell you how many points you have selected. If you have more than 1, then I suspect it's made 2 different objects that just happen to be really close to each other. Just hit "m" and then hit enter, and modeler will combine all the points in that area (the really close ones) to a single point , thus merging your two objects together.

jhopfenblatt
04-27-2005, 02:29 AM
Just for the heck of it I did the same thing you were doing and got the same results. Hmmmn, strange. I'm a newb too, so you might wanna wait for someone else to explain why that happens. :(

Anyway, here's what I came up with after I merged the points, as I explained above.

http://img.photobucket.com/albums/v467/Comatosis/lightwaveillustration.bmp

Does that help you solve the problem?

Dodgy
04-27-2005, 04:57 AM
The extrude tool was originally used for extruding fonts, so it left a copy of the original face in place as a new one was extruded.

Use Smooth shift (ctl-f) to make some connected faces, then move this...

Surrealist.
04-27-2005, 05:53 AM
The extrude tool was originally used for extruding fonts, so it left a copy of the original face in place as a new one was extruded.

Use Smooth shift (ctl-f) to make some connected faces, then move this...

Probably just a typo bud but in LW8 It's "F" (Shift f) for smoth shift.

Also another tool that is really powerful is the tool you started with, the bevel tool. It's interactive (as is smooth shift and supper shift) but for some things like the example above it works great.

To get the hang of how it works select the top polygon of a box, hit the b key and with the ctl key held down drag left to inset and restrict movement to that plane. EDIT: (While in the perpendicular viewport ctl. will restrict to inset only, while in a viewport facing selected poly it will restrict to shift) Then just right click once and then click and drag with the LMB and move the mouse forward(up) and the polygon will extrude up. As you extrude it you can interactively move the mouse right and left to taper the bevel. Each time you want a new bevel just right click once.

Doing it on the top polygon of a box is a great way to get used to the visual feedback of the tool. Up for extrude, right and left for bevel.

Just kind of a cool tool, simple as it is. For some things, it's just the ticket. You can make a lot of real interesting shapes real fast this way.

Extender plus is another dandy, but for simple symetrical shapes bevel is nice and it's subpatch freindly.

Verlon
04-27-2005, 06:32 AM
I didn't read the whole thread, so forgive if its been answered already.

You said you created 4 points in a plane (as opposed to say making a box but not drawing out the 3rd dimension). The order you select those points (and maybe the order you create them if you don't select them to make the polygon--have to ask a smarter LW guy for that) will affect your normals.

For example

1 2
4 3

would create a polygon with a normal facing the back of the moniter. Extruding up from this would have the polygons facing the inside of the box (if memory serves).

1 4
2 3

would create a polygon with a normal facing you, the viewer. Extruding up from this would create polygons facing the outside of the box (or the opposite of above, so if I was wrong there.....)

1 3
2 4

would create a non-planar polygon. Extruding up from this would create chaos, I think. Since I learned in a Larry Shultz (aka Splinegod) tutorial the importance of polygon creation and selection order, I have tried to be very mindful of this.

Since you said you were getting chaos, I was thinking maybe you were extruding a non planar polygon.


Verlon

Surrealist.
04-27-2005, 02:32 PM
I didn't read the whole thread, so forgive if its been answered already.



Actually what he was getting was what happens if you first bevel the side of the box, once created - however - and then bevel with a 0 shift, select the inner pollygon, extrude with the extrude tool and then sub patch. This leaves the extruded area disconnected from the box because of the attributes of the tool as Sikrooster pointed out.

The other issue was with the way one extrudes to do with the direction of the poly normal and the extrusion as to wether or not you have to flip pollys after the fact.

Aidan:

BTW since you were trying to model the wing of a spae ship, check out a tut on Larry's site where you create a space ship with a wing.

http://www.3dtrainingonline.com/support/