View Full Version : Merge Polys Problem

05-16-2007, 10:47 PM
I am working through Larry Shultz' Industrial modeling Vol 1 and so far I have taken a disc, copied and pasted it, moved one over, used split to cut them both in half, got rid of the inside halves ... and now I am trying to connect them ... so I choose the top and bottom points of each half circle, hit p to make the in between polygon ... it forms but it is black and does not have a handle like other polys ... and then when I hit Shift/Z to merge I get an error message that tells me "Faces do not share edges, and/or curves do not share endpoints."

I am following exactly the training, but it won't let me past this. I believe he used LW 8 in the training video ... has something changed that will not allow this procedure in LW 9? How can I work around this?


05-16-2007, 11:22 PM
Larry's around here from time to time, he might have a better answer. But I am going to say that it never hurts to go over it again fresh. Make sure you are not missing something.

A black poly with no normal means it is non planar which could be because there are duplicate points or a few other reasons, but would not be able to tell without a picture of what you are trying to do.

Post a picture if you can and explain the steps in more detail.

05-16-2007, 11:40 PM
You have to select the 4 points not just 2, then p and then merge. Make the
selection counterclock wise if you're working in the back view. Selecting just
2 will give you a 2 point poly or just a line. That's why you see a black line
without handles ( normals ).

05-17-2007, 12:26 PM
'SHIFT+Z' is for merging two already existing polygons that border one another with the intent of removing the edge that divides them, 'M' is the command to merge points, which has the knock on effect of welding the polygons that own those points together. It is not unusual to find that as a byproduct of this act that troublesome black polys turn back to a more normal grey

05-17-2007, 12:30 PM
If the tutorial explicitly states 'SHIFT+Z' the error message is due to the fact that the polys are discontinuous and need to be welded ('M') first

05-17-2007, 03:45 PM
The dreaded black poly. If it's black then you are gauranteed to have some messed up geometry. Try killing you poly by hitting K and then rebuilding it by selecting the points and hitting P. That will usually do the trick.

05-18-2007, 02:44 AM
Sometimes, I find the simple act of merging, tripling, then merging again can remove eh black poly thing. Dunno why it should, but there it is. :)

05-24-2007, 12:22 PM
If the tutorial explicitly states 'SHIFT+Z' the error message is due to the fact that the polys are discontinuous and need to be welded ('M') first

This was the right answer!! Thansk gerry_g! :bowdown:

05-24-2007, 12:39 PM
"black poly" as you call it, is usually 5 or more point polygon that looks like 4 point polygon because two, start and end points are in the same positions (therefore polygon normal can't be correctly calculated - it's made from first, second and the last polygon vertices).