View Full Version : The flipping polygons

06-10-2003, 02:06 AM
Does anyone know how to change double-sided polygons back to single sided polygons in LW 7.5c? I know it shouldn’t technically matter in renderer because you have to explicitly tell LW to see double sided Polys, but what if you want change back to singles (or is it ‘till death us do part’).

06-10-2003, 02:18 AM
If your polys are of two different surfaces, you have to make them the same surface then use 'unify polygons' This eliminates any polygons which share the same points, leaving one behind.

06-10-2003, 05:09 AM
Thanks Dodgy, but this isn't the answer.

06-10-2003, 10:39 AM
Then could you explain more fully what you mean? There's only 2 ways for polys to be visible from both directions in lw,
1/ Have Doublesided on in the surface of the polygon. Turn this off to make them single sided again.
2/have doubled polys facing in opposite directions. These can be eliminated by merging them together, so that you know they share corner points, change their surfaces to the same surface (unify won't work on doubled polys if the surfaces are different for obvious reasons) and then Unify the polys. This leaves you with one poly facing one direction.

06-10-2003, 11:02 AM
It’s the first one, an object with double sided polys. If I go to surface editor in modeller double sided is off yet the object is still showing double sided polys.

06-10-2003, 04:02 PM
Could you send me the object? I might be able to fix it, or at least diagnose the problem :)

06-10-2003, 05:36 PM
merge points + unify polygons + align

06-11-2003, 03:30 AM
OK I have merged points – no points to merge
Unify polygons – no polygons eliminated
The polys are still double sided.

I also tried to replicate this but I couldn’t find the make2sided command.
Detail > Polygons: Make-2 Sided

I go Detail > Polygons: (but there is no make-2 Sided)
All the modeler plug-ins are loded (maybe it got bugged when I upgraded to 7.5c?

The new help system is inadequate, it needs a better search engine, the advantage of having an online manual is the search, but this one fails on many counts – type in ‘double sided polygons’ and it tells you ‘no pages match your search’. Nuts.

PS my settings are as default, it's never been changed.

06-11-2003, 04:02 PM
Check the surface setting for the surface that you want to be single side. There is a radio button to make the surface double or single sided.

John Fornasar
06-11-2003, 05:49 PM
The new help system is inadequate, it needs a better search engine, the advantage of having an online manual is the search, but this one fails on many counts – type in ‘double sided polygons’ and it tells you ‘no pages match your search’. Nuts.

Try searching on just "double"...
Here's what you'll get:

Detailing Geometry: Make 2 Sided

Make 2 Sided

Sometimes you’ll actually want double-sided polygons, like when you need to go inside a hollow object. Most of the time, you can get away with simply using the Double-sided surface attribute on the Basic tab of the Surface Editor. However, if you need to actually model the double-sided polygons, it is pretty simple. Just choose Detail > Polygons: Make-2 Sided.

It is also possible to make double-sided polygons manually using the following procedure:

1 Select the target polygons (even if it is the entire object).

2 Copy (c) the selection.

3 Paste (v) the selection.

4 Choose Detail > Polygons: Flip to flip the (still) selected polygons.

5 Choose Construct > Reduce: Merge Points to merge points.


For your Make Double Sided button, don't know why you don't have it, but go into Configure Menus, look in Additional (the first selection) - you'll find Make-DoubleSided in there, then you can put it in the Details-Poly section (or where you want it).

06-12-2003, 02:18 AM
I have just checked, the plugins is in the plugin folder (model). But it doesn’t show up on the additional tab (Configure Menus, look in Additional), I guess its bugged in some way, I am not sure how you fix it – rerun the upgrade?

I did do the double search, the thing is you shouldn’t have to, the help system needs a decent search function attached to it, the whole thing is badly organised – do a search for ‘DoubleSide.p’ it tells you ‘no pages match your search’ there should be notes on each plugin.

Still can’t figure how to change those double sided polys.

John Fornasar
06-12-2003, 02:39 PM
Try re-adding the plug-in:

Modeler/Plugins/Add PlugIns
drill down to the Model directory, and select Doubleside.p

you should get a message "1 Plug-ins found in 1 files".

Then you can locate it and assign a button or a keyboard shortcut.

06-12-2003, 03:58 PM
There appear to be some type of bizarre anomaly on the Mac in 7.5c.
7.5c tried to install the OS9 doublesided.p into the OSX install.
When you look at the OS9 7.5 install its there (the master CD’s),
But not 7.5 OSX master CD.
At a guess I think the programmers forgot to translate it to OS X.
Other lost soles in OSX appear to be:

John Fornasar
06-12-2003, 04:00 PM

pc guy here, no clue about macs, you may want to check the mac forum...

good luck...

06-12-2003, 05:34 PM
well, one problem has led to another again.

06-14-2003, 02:32 PM
Does this mean that changing a double sided poly to a single sided poly is not possible inLW 7.5? Usually someone is able to say well it's 1,2,3 easy, but everyone has been defeated by this, me thinks?

06-15-2003, 03:38 AM
I just found and installed "Doublesided.ls" (check the Lscript folder), made a poly double-sided, merged points and then tried "Unify polygons" and it worked, single-sided polys again - maybe some of your points aren't merging - try allowing some tolerance when you merge points -

or post your model so we can take a look at it

06-15-2003, 09:53 AM

I think there is a problem with a missing LScript in OS X. I was able to add "DoubleSided" from "Additional" to the detail menu, but when I used it I got an error saying that LScripts/model/DoubleSided.ls could not be found. I searched my entire drive and couldn't find "DoubleSided.ls" I did find "DoubleSide.p" in the OS 9 version, but didn't think it would work.

I searched for "Double" on Newtek's site and found a page with OS X update files:


On that page was a link to download "DoubleSided.sit", under LightWave 6.5 Missing Plug-ins Update, described as, "LScript to replace missing DoubleSided plug-in." I wasn't comfortable about the fact that it is the 6.5 version, but I downloaded it, put in it /LScripts/model/DoubleSided.ls and I can now make polygons double sided. I hope that it is ok.

There are some other downloads on that page that might be of interest.


06-15-2003, 01:16 PM
Thanks everyone. I got completely confused with the Doublesided.p because all manuals were telling me to look in plugins and load it from detail-> surfaces, then it didn’t appear under additional, finally thanks to Whit I loaded all the Lscripts (didn’t realise that some plugins were Lscripts and that they had to be explecitely loaded like plugins . Why are some already there while others have to be loaded?). Also what is the cost of loading plugins, is LW smart enough to only use memory for a plugin when it is being used or is there a drag on LW for every plugin loaded?
Modeller appears to have problems with imported double sided polys, it cannot change them to single sided, there is no problem with polys created in modeller .
Tried to upload the .lwo file but the Forum wouldn't let me.