Extrude Problem

magnum

Hello All, this is my first post in this forum, i have a question regarding using the extrude tool while modeling, and while i use C4D, i think this question apply for other programs as will
 
and so my problem is best described using the following image


as you see in the image, when i extruded the polygon that is highlighted in the second image, the other polygon which sit right beside it is still there, where the normal behavior which you would need is that they marge together, as you see in the third image when i moved the other polygon, i revealed a pointless polygon that was sitting there, that is completely unneeded 

so is there is a way around this, what could be done to have a clean extrude without the hidden polygons that you might create without noticing

Bek

This is just something you need to work around really. There's plenty of ways to quickly fix the problem, but no automatic way to do this (that I know of). You're probably better of using edge extrusions in such a case rather than polygonal and cleaning up anyway.

magnum

Hi BEK, can you expand more on what is the best way to clean up the extrusion, even though im surprised that there is no actual tool to make clean extrusion, its very hard to Recreate things every time you have to make an extrusion

Bek

There are tonnes of ways you could do the same thing, whatever is "best" is whatever you find quickest/easiest. You could slice across the cube (snapping to the extrusion's end), delete the hidden face and merge vertices. You could delete the righthand cube and do two extrusions at different values to create the halfcube + recreate deleted cube. You could extrude the edges instead as I mentioned before. You could do a slice then delete the unwated faces then extrude. The most important thing really is recognising that your extrusion will cause this problem so you can fix it.

SonicBlue

Quick video to solve this particular problem:

http://www.youtube.com/watch?v=qf8ByvJA77U

The various techniques involves a certain degree of cleaning, even if you delete the face if you wanted to extrude, so that it doesn't create that extra polygon yo don't want, extrude only 3 edges, then close the hole. You'll have to cut the other face, delete the half you don't need and connect back together the mesh with Optimize (U~O).

peteed

Merge the top two verts to centre and the bottom 2 and then zoom inside your object and select the 2 faces left in there and delete them

Delete the already extruded faces and fill that hole and then click both faces and extrude them together this time

Pull them apart like what you did in your 3rd image and delete the 2 faces and then merge the verts to centre

Few ways of doing it

magnum

Hi SonicBlue, the video you posted is very interesting, but i cant understand what you did, after you extruded, you moved to the top view and then made a cut, im not sure if this cut is just on the upper polygon, or sliced down all the faces, also after you made the selection at 0.04, im not sure what you did then, you seam to be doing something with the keyboard shortcuts, please reply, i feel you got the right method

SonicBlue

http://youtu.be/VYEIT4i6Hr4


I did it faster the first time since I have a pretty slow internet connection, especially in upload, anyway.

The suggestions in this thread are all part of the same technique, which consist on cleaning up the mesh after the extrusion. In this case it was easier to select the inner face from the top view with the rectangular selection tool (0, zero on the keyboard) since there are no other parts you can accidentally select, but usually you have to go inside your mesh to do that.

Use the Subdivision Surface to see if your mesh have some problems in combination with Mesh Checking (SHIFT+M), Boundary Edges displays open meshes and Complex Poles highlights points with more than 5 polygons. The Knife cut was done in Line mode with Visible Only ticked off, quickly called with the Help4D scripts, I've then assigned Line assigned to ALT+F1 and Loop to ALT+F2.

At 0:04 I just deleted the previously selected polygons with Backspace, after that I run Optimize (U~O).

magnum

success, i was able to do it, i tried to do the same things before with the knife and optimizing but i couldn't make it,
i see now that i should have modified the knife tool attributes for it to work