# Lining up vertices, and subdividing help

I am attempting to model the Armalite AR-50 rifle using the reference images here and here. Im running into problems ive had the entire time that ive been learning modeling concerning the exact placement of vertices.

Here is the .blend file i am working on.

Problem #1

I am trying to extrude vertices A, and B down, and verts C, and D back (see picture below). The problem is the two points that they will intersect how do i get verts there? I have tried using “Display selected edge length” and also the coordinates in the “Transform properties” window to calculate the distances, which almost works…even if i move the verts the exact distance, they are still off when you zoom in. Also i have no verts at the intersect locations, if i did i could use the snap commands

Problem #2

This problem is a vert that is not part of an edge that i want it to be (pic below). I want the highlighted vert to be part of edge A, but when you grab it and pull it away, you can then see it has its own edge.

Problem #3

(pic below)
When i select and edge or 2 verts at the ends of the edge and then subdivide, it subdivides it fine but it makes new edges forming triangles from other verts. I have noticed though that if you delete the faces that are touching the edge, then subdivide it, then manually put faces back in, it will work. I guess what im asking here is, can you subdivide an edge without removing the touching faces, and not get the extra edges? like creating non-manifold verts.

heh, i feel dumb asking such questions, especially considering how long ive been trying to learn modeling in blender
thanks for helping guys If anybody knows of a gun modeling video tutorial, i would love to see it…or if somebody could create one??

Well at least one of your problems will be solved (the second one ;))

First delete the face and the edge so you get what you can see in the first image. Then select the three vertices (as seen on second image) and press “f” to create a face. repeat the process on the other side. Finally select the four vertices as seen on the last image and again press “f” to create a face.

1. Extrude A and B first. Extrude C and D, then individually snap C to A and D to B?

2. no You can’t subdivide only half an edge and that’d be essentially what you were doing. There would have to be two edges there.

thx lamoot

Enzoblue, i dont know how far down to extrude A and B… I want them to meet at a 90 degree angle, and the distances are’nt exact like 1.680, its more like 1.67975834983 or something

If you make a face using A,B,C, and D. Then subd the two edges between a/c and b/d, then select A or B, move cursor to selection, then select the two new verts created by the subd you just did, change rot/scale pivot to use the 3D cursor, then hit <S> to start scaling, hit <X> to constrain to x-axis, then hold the <CTRL> key, and scale to 0.
The two verts will be lined up with A,B vertically, repeat the steps using C and D, moving the cursor to them, then scaling the new verts along the z-axis until they reach zero and the two new verts will be right where you want them.

Video of what I did: http://hdiss.net/bpeters/AR-50.wmv

Note: you do not have to select both A and B, or C and D, lining up the cursor on just on of the verts at a time is fine, I lined the cursor up with both out of habit. Also I think you will want to cut the lower edges 4 times to make verts to match up with the geometry above for making the inner faces.

Awesome! Thanks Hazard, you’re a genius im sure ill be coming back to this thread for help with this bit.

Also I think you will want to cut the lower edges 4 times to make verts to match up with the geometry above for making the inner faces.

i cant see how to line them up perfectly with the verts above them but ill see what i can do.

Select the edges and press <K> for knife tool and experiment.