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DR Ice
11-28-2007, 12:29 PM
Hello Lightwave Folks!
I am currently working on a technical animation for a documentary and having a problem (challenge) with modeling an organic cube. The sides are complex epsf files from Illustrator and the top edges are not straight (think scalloped edges). This issue is trying to create the lid for the cube by selecting the points along the top edges of the 4 sides (in order) and selecting 'make polygon'. A dark brown polygon is created which is basically useless.
I've also tried breaking up the lid poly into smaller sections with no success.
Phone tech support guy was nice, but had no suggestions (other than post here).
Any help would be greatly appreciated!
Thanks,
D

UnCommonGrafx
11-28-2007, 01:00 PM
Ignore the big brown polygon and render it in layout.
Did the ugly brown polygon show itself? I'm betting not.

What's happening is that is a degenerate poly. Ignore it in Modeler and it will still work right in layout.

Surrealist.
11-28-2007, 01:11 PM
Welcome to the LW community. :)

What you have is a non planar polygon. You can use the search function at the top of this page search for that as a title you will find threads such as this (http://www.newtek.com/forums/showthread.php?t=72901&highlight=Planar+polys).

This should give you a good education on what they are and how to deal with them.

But for an organic model you want to subdivide your model into quads and then triple it. So for the top just use the add edges tool to connect and create a grid of quads along the top of the uneven surface. If the rest of your model is uneven do the same. After this use the Shift T command to triple the model and with smoothing applied will be good to render. Just think keep it simple and even your mesh as much as possible.

One way to have a cube that is uneven is to make a box with the box tool, use the arrow keys to ad segments in both directions and then use the jitter command (Shift J) to give it an uneven appearance. Of course trippe when done.

Subpatches are a great way to have an organic shape. At render time the polys are automatically subdivided and tripled.

EDIT UnCommonGrafx brings up a good point. If it is only degenerate it may render OK. To check, open up the stats window while in polygon select mode and look for any Non Planar polys.

DR Ice
11-28-2007, 04:20 PM
Thanks much for your replies. Adding edges to the existing non planar polygon causes Modeler to crash. Now I'm manually adding points and creating planar polygons one at a time. Should be done in a couple of days! Seems like there ought to be a faster method than this, but the top edge uneveness is not arbitrary and needs to conform precisely (point for point) to the epsf files.
Thanks, UnCommonGrafx, but the non planar poly will not render in Lightwave as is, and does not respond to Surface Editor either.
D

UnCommonGrafx
11-28-2007, 06:36 PM
Then you've piqued my interest...

Can you post that object for us to learn from?

Edit: if you can't post the object can you try the following?
Select this problem poly and press "F". Render it again and see if it shows up. I am curious.

Surrealist.
11-28-2007, 07:38 PM
Thanks much for your replies. Adding edges to the existing non planar polygon causes Modeler to crash. Now I'm manually adding points and creating planar polygons one at a time. Should be done in a couple of days! Seems like there ought to be a faster method than this, but the top edge uneveness is not arbitrary and needs to conform precisely (point for point) to the epsf files.
Thanks, UnCommonGrafx, but the non planar poly will not render in Lightwave as is, and does not respond to Surface Editor either.
D


Sounds like a lot of points in that object. I'd have to see it to suggest any shortcuts - if any. :)

Sekhar
11-28-2007, 08:00 PM
DR Ice, I'm guessing you're not selecting the points in sequence before making the poly (the order in which you select matters, wrong order can get you a bad poly that Uncommon mentioned). Rather than lasso the points in, select the points one after another in sequence, and you'll be good.

Attached is a sample to show what I'm talking about. First layer has a closed curve, second an extruded version, third a bad poly top (that you're getting) because I selected top points with lasso, and fourth a good poly top because I selected the points in sequence.

DR Ice
11-28-2007, 09:30 PM
First of all, thanks much for quick responses to my post.
Sekhar, thanks but I'm well aware of the importance of selecting points in the correct order. Wish it was that easy a fix.
Surrealist, thanks for giving me the correct term for my current nemesis and also the thread.
UnCommonGrafx, attached is a Modeler screenshot with a more simple cube object so hopefully you can get some idea of the problem I'm trying to deal with. It's funny in the 8 or so years I've been working in Lightwave I've never encountered this particular issue! As I mentioned before, I can manually create a mesh of polys to create a lid for this cube, but it seems like one ought to be able to accomplish the task quicker than that. The red selected points along the top perimeter of the sides of the cube are what I've been trying to mak a lid from.
Thanks all,
D

Surrealist.
11-28-2007, 10:36 PM
For something like that I would seriously consider not matching it point for point but use a curve and approximate as close as you can get. If not you can still do it with a spline using spline patch.

Use four splines, one for each side.

I suggest picking two points along the top and using select loop then deselecting to get one side. Make note of the number of points for each of the two sides that have all the points that need to match.

Cntl. p to make each spline.

Once you have the four splines make sure they are end to end (flip if need be) and then use the Spine Patch tool.(in another layer of course) Enter the number of points for each side so that the mesh matches up as I did in my requester shown. You may have to experiment to see which is which - based on the order of how you select the splines.

From there you can paste it back in and merge or perhaps weld points to the edge (one of my edges did not match up exact though it was the correct number of points).

Also you may want to do this in sections for yours.