Blender Documentation: Last modified July 31 2003 s68
<<< Previous | Mesh Modelling | Next >>>

# EditMode

## Introduction

When working with geometric objects in Blender, you can work in two modes: ObjectMode and EditMode. Basically, as seen in the previous section, operations in ObjectMode affect whole objects, and operations in EditMode affect only the geometry of an object, but not its global properties such as the location or rotation.

In Blender you switch between these two modes with the TAB key. EditMode only works on one object at a time: the active object. An object outside EditMode is drawn in purple in the 3D Windows (in wireframe mode) when selected, black otherwise. The active object is drawn black in EditMode, but each vertex is highlighted in purple (Figure 4). Selected vertices are drawn yellow (Figure 5).

Figure 4. Two pyramids, one in EditMode (left) and one in ObjectMode (right).

Figure 5. Cube with selected vertices in yellow.

Most simple operations from ObjectMode (selecting, moving, rotating, scaling) work identically on vertices as they do on objects. Thus, you can learn how to handle EditMode very quickly. The chopped-off pyramid in Figure 6 was created with the following steps:

1. Add a cube to an empty scene. Enter EditMode.

2. Make sure all vertices are deselected (purple). Use border select (BKEY) to select the upper four verices.

3. Check that the scaling center is set to anything but the 3D cursor (see Figure 2 in the Section called Rotating objects), switch to scale mode (SKEY), reduce the size and confirm with LMB.

4. Exit EditMode by pressing TAB.

Figure 6. Chopped-off pyramid

One additional feature of EditMode is the CircleSelect mode. It is invoked by pressing BKEY twice instead of only once, as you would for BorderSelect. A light gray circle is drawn around the cursor and any LMB click selects all vertices within. NUM+ and NUM- or the mouse wheel, if any, enlarge or shrink the circle.

## Structures: Vertices, Edges and Faces

In basic meshes, everything is built from three basic structures: Vertices, Edges and Faces. (We're not talking about Curves, NURBS and so forth here.) But there is no need to be disappointed: this simplicity still provides us with a wealth of possibilities that will be the foundation for all our models.

Vertices

  A vertex is primarily a single point or position in 3D space. It is usually invisible in rendering and in ObjectMode. (Don't mistake the center point of an object for a vertex. It looks very similar, but you can't select it.)

  Create a new vertex in EditMode by holding down Ctrl and clicking with the LMB. Of course, as a computer screen is two-dimensional, Blender can't determine all three vertex coordinates from one mouse click - so the new vertex is placed at the depth of the 3D cursor 'into' the screen. If another vertex was selected previously, they are automatically connected with an Edge.

Edges

  An edge always connects two vertices with a straight line. The edges are the 'wires' you see when you look at a mesh in wireframe view. They are usually invisible on the rendered image - their use is to construct Faces. Create an Edge by selecting two vertices and pressing FKEY.

Faces

  A Face is the most complicated structure in a mesh, building the actual surface of the object. This is what you actually see when you render the mesh. A Face is defined as the area between either three or four vertices, with an Edge on every side. Triangles always work well, because they are always flat and nicely easy to calculate. Take care when using four-sided faces, because internally they are simply divided into two triangles each. This only works well if the Face is pretty much flat (all points lie within one imaginary plane) and convex (the angle at no corner is greater than or equal to 180 degrees). This is the case with the faces of a cube, for example, which is why you can't see any diagonals its wireframe model, that would divide each square face into two triangles. It would be possible to build a cube with triangular faces, it would just look more confusing in EditMode.

  An area between three or four vertices, outlined by Edges, doesn't have to be a face. If no face was created, this area will simply be transparent or non-existant in the rendered image. To create a face, select three or four suitable vertices and press FKEY.

All operations in EditMode are performed on the Vertices; the connected Edges and Faces automatically adapt, as they depend on the Vertices' positions. To select an Edge, you must select the two endpoints; to select a Face, each corner must be selected. You need to select Faces for some operations, e.g. erasing Faces (XKEY, then select 'Faces' from the menu. Erasing a Face also erases its Edges and Vertices if they are not used by other Faces).

Each Face has a normal vector that is used for lighting calculations. You can see these vectors as blue lines if you activate 'Show normals' in the EditButtons. To ensure proper lighting, you should make sure that all normals point out of the visible side of each face. If a normal points inwards, select its face and press 'Flip normals' in the EditButtons.

## Specials

With WKEY you can call up the "Specials" menu in EditMode (Figure 7). With this menu you can quickly access functions which are frequently required for polygon-modelling. You will find the same functionality in the EditButtons F9.

| Tip
| You can access the entries in a PopupMenu by using the corresponding numberkey. For example, the keypresses WKEY, 1KEY, will subdivide the selected vertices without you having to touch the mouse.

Figure 7. Specials Menu

<<< Previous | Home | Next >>>
ObjectMode | Up | Smoothing