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View Full Version : Lightwave 11 issues - Polygon selection and angles - Please help a n00b



sledgecallier
01-30-2013, 06:28 AM
Hi there,

I am currently using Lightwave 11 to model an object for 3D printing. However, I am currently facing a couple of issues that I am hoping the forum can help me with. (I confess I am still learning Lightwave so please bear with me.)

First problem is occurring when trying to select polygons. A simple task, you would think, but I am getting a situation where I am trying to select a polygon but instead the application is either selecting a polygon from a side below the required polygon, or not selecting a polygon at all. It almost seems as if the focus point of the cursor is not focusing on the top polygon? My guess is that there may be a setting somewhere that defines what is selected, but cannot seem to find anything anywhere? It has to be said that if I zoom a way out from of the surface and ensure the face is truly face on then I can select the polygon required, but with small scale, detailed models many of the polygons are quite small. (I am possibly not making much sense, but hopefully you see the problem I am having?)

The other problem is more related directly to the fact that I am modelling for 3D printing. As a rule, it is best to not have any polygons with zero degree angles. (I am trying to rule out zero degree polygons but using boolean joins to give me a single shell seems to make this inevitable?) My question is this, is there some way within Lightwave to highlight or show where any zero degree polygons exist within a model? The statistics panel doesn't seem to have this level of detail, and again, I can see nothing in the manuals or help files that would assist?

Many thanks.

zardoz
01-30-2013, 06:56 AM
well about selecting the polygons...at extreme zoom and angle it may be hard to select polygons, but if you zoom out you should be able to select any polygon. Also notice that selecting polygons depend on the type of display: with color wireframe you can select polygons in front, back, etc, while with other display like wireframe shade it 'raytraces' the selection and doesn't select polygons in the back (at least it shouldn't but it isn't perfect). If you are zooming to select very small polygons, try to select them in one of the ortographic views like top or back with color wireframe mode, and then try to refine that selection in the perspective view.

about the 0 degree polygons I don't understand what is a zero degree polygons...can you explain that?

jwiede
01-30-2013, 07:08 AM
about the 0 degree polygons I don't understand what is a zero degree polygons...can you explain that?
Perhaps referring to a poly where two adjacent edges (line segments) are colinear (iow, containing a "0-degree" vertex angle -- essentially a "zero area" polygon/line segment)? That seems to fit the description given, and can cause problems with 3D printing.

sledgecallier
01-30-2013, 07:19 AM
Perhaps referring to a poly where two adjacent edges (line segments) are colinear (iow, containing a "0-degree" vertex angle -- essentially a "zero area" polygon/line segment)? That seems to fit the description given, and can cause problems with 3D printing.

Yes, that's what I was trying to convey. Sorry if I wasn't overly clear.

With the selection, I think the problem is with the zoom required to actually see the polygons to select them, but I will try in an Orthographic view to see if that improves the situation.

Many thanks guys.

zardoz
01-30-2013, 07:29 AM
so merging the points first with automatic range and second with a very small fixed value would fix this? (then delete all 2 point polys)

gerry_g
01-30-2013, 07:39 AM
shuld always have numerics open for this stuff (n to open) LightWave has no auto mesh cleanup

sledgecallier
01-30-2013, 07:46 AM
I think the problem there will be when the three sides of a polygon are of differing length, so the corner points don't line up. (Again, sorry, struggling to put into words fairly graphical concepts.)

Hail
01-30-2013, 08:33 AM
I think the problem there will be when the three sides of a polygon are of differing length, so the corner points don't line up. (Again, sorry, struggling to put into words fairly graphical concepts.)

Can you show a screen grab of what you are trying to explain or perhaps share the object file if possible? its difficult to know whats going on with your object without a shot.

zardoz
01-30-2013, 09:11 AM
I see what you mean...it's like moving a triangle's tip down to it's base...this way you just can't merge any points and you get a 'line' that actually is a triangle with zero area...for now I have no idea how to get rid or fix these...I know that lwcad has an option to fix things like this and it will simply delete these polygons leaving holes in your mesh...

110813

sledgecallier
01-31-2013, 02:34 AM
LWCAD would certainly help as it's a lot easier to spot holes in a model than zero area polygons, but not really wanting to drop an extra $300 on something that is currently just basically a hobby. The real issue is spotting them, but if there is no inbuilt facility or script to flag these troublesome polygons then I guess I'll just have to go down the old route of manually cleaning up and spotting duff polygons in the model. Many thanks for all of your suggestion though, it is much appreciated.

sami
01-31-2013, 02:58 AM
Also, for your selection issues, have you tried putting the viewport in Texture mode? When it is in wireframe you can select through polygons and may accidentally select a poly one the other side. is that what you mean? With a solid viewport setting the surface "blocks" clicking through and only selects the polygon you touch the surface of.