Can I cut faces?

Hi there. I’m a brand new member to the Blender forums.

I was wondering if it’s possible to cut faces along an adjacent face. My current (and first) project is the USS Enterprise 1701-D. The current problem I’m having is a cut-out section on the saucer for the engines.

http://img254.imageshack.us/img254/7759/1701d33gu1.jpg

The faces that are intersecting the saucer is the area that needs to be cut out. Can this be done?

Hi, welcome to Blenderartists! There are two ways you could do this, but one gives a messy mesh. The other gives a much cleaner mesh, but may be a bit less exact.

Option 1: Booleans. (messy mesh)
Make the shape you have there showing your cut-out area a solid block. Select the block, then shift click your saucer in object mode. Hit the W key, then difference. Move both selections out of the way to see your saucer with the cut out.

Option 2: Knife cut. (clean mesh)
With your saucer selected in edit mode, hit the K key and choose knife exact. Click to place the beginning of the cut. Keep outlining your cut by clicking where you want each corner. Hit enter when you’re done. (Sorry if this explanation isn’t real clear, I tried.):slight_smile: Delete the vertices you don’t want and fill in the holes they leave by clicking four vertices then hitting the F key to make a face.

Thanks for the heads up on the Specials menu (W key), LOTRJ. I’ve never used that before, but it definitely will work for me. The only problem I’m having with that is making 2 objects. When I go into Object Mode, both the ship and the cutting plane are joined together so I can’t delete the cutting plane without deleting the ship. How do I separate them into different objects?

First select the cutting plane by pressing “L” while your mouse cursor is over one of the plane’s verticies to select all the verticies linked to that vertex then press “P” and select “SELECTED”. If the ship and the plane have no common verticees it should work and you will have 2 objects

Well, I tried that, but I’m getting an error saying “Can’t separate with vertex keys”.

Please, please, please help!!! I don’t know how to fix this!!!:frowning:

Vertex keys are also known as shape keys. The error message hasn’t been updated, I guess. Anyway, you find the shapes panel in the Button window editing panels. If you open an Action Editor window (drowning man or shark attack icon) you’ll see all the shape keys (aka sliders) that you must delete in order for the separate tool to work. Delete the shape keys by clicking on the X button in the shape panel.

Thanks so much for the help!!! Now I got it to work.

http://img109.imageshack.us/img109/6211/1701d34xy8.jpg

Just some clean-up to do. I think using the Booleans might work on the windows as well.:confused:

I’ve got a super big question now.

I need to move some edges for some detail work on the saucer. I don’t know the angle or the exact distances. Is it possible to just select some edge vertices and use the Grab command to move an entire edge to a specific vertex so that one of the edge vertices lines meets the target vertex? I keep thinking that it can be done with the 3-D cursor and the Snap command (I’ve done it with individual vertices before), but I don’t know how to move an edge or an entire face that way.

You can select something and use shift-s to snap the cursor to the selection, then select something else and use shift-s again to snap the selection to the cursor; that may let you do what you want.

Doesn’t seem possible. Snap to cursor will snap all selected vertices to the cursor, they will all meet in a point instead of being lined up.

You can get vertices lined up in a stack by using scale: select the vertices, type s then Shift x, y or z, then 0.

If you type x, for example, the vertices will line up along the x axis (ie: they scale to 0 along both the other axes.) Then in side view you can grab and move that lined up set of vertices to the correct yz coordinates.

I think this method only works for global x y and z axes, so if your model is not lined up on the global axes, you may need to rotate it before doing this.

I’ve just upgraded to Blender 2.46 and I’ve noticed a problem with the starship I’m working on. I can’t be able to select the faces because there’s no dots for the centers of the faces. And I’m trying to get several faces cut for windows, hull details, etc. Does anyone know how to turn the face centers on and off?

Do you have Face select enabled? Press Ctrl-Tab and 3 (faces). The center dots should show-up for the faces.

Faces are already selected. The dots just aren’t showing up. If I still can’t get the face dots to show up, I might have to re-install Blender. There might be a problem with the installation I did last night.

Sorry, I just noticed they do not show up if you are in Textured or Shaded draw mode. 2.46 added the ability to see your UV textures even when in Edit. Make sure you are in Solid or Wire frame (Press Z).

Got a problem here. I can’t seem to get these two faces separated. When I do I get this message:

ERROR
Unknown internal error in Boolean

Can anyone help?