Blender 3D: Noob to Pro/Improving Your House

Your goal.

In this module, you'll refine the house model you created two modules ago. In the process, you'll learn how to access Blender's predefined meshes and how to set a pivot point. You'll also learn how to select, extrude, delete, and subdivide the edges and faces of a mesh model.

To begin, set up Blender as follows:

1. Launch Blender and load the factory settings.
2. If you have a numpad, make sure NumLock is on.
3. Load the house model you created in the "Quickie Model" module.
4. If the 3D manipulator is active, disable it.
5. Adjust the viewpoint until you can clearly see two walls of the house and two sides of the roof.

Adding a Ground Plane

Your house needs some ground to rest on. You can model the ground as an object in your scene. Blender has many predefined mesh objects built in. Happily, one of these is a flat, square surface.

Recall that new objects are added at the 3D cursor. Before creating the ground, you should position the cursor at ground level:

1. Select the house by clicking  RMB  on it.
2. Enter Edit Mode by pressing  Tab .
3. Select one of the bottom vertices by clicking  RMB  on it.
4. Bring up the Snap menu by pressing  Shift + S .
5. Choose Cursor to Selected.
6. Leave Edit Mode by pressing  Tab  so your ground is created as a separate object.

There's an "Aligned To View" setting in the "Editing" tab of User Preferences which is off by default in Blender 2.5x. When this setting is on, the orientation of new objects depends on the current viewpoint. Pre-2.48a releases of Blender had "Aligned To View" on by default. If you've turned this setting on (or are using an old release) go to "top view" (by pressing  Num7 ) before creating the ground object.

The ground added.

Now create the ground object:

1. Activate a 3D View window.
2. Press  Shift + A .
3. Choose Mesh → Plane.

The scaled ground.

To enlarge (or scale) the ground object, use the scale tool:

1. Make sure Blender is in Object Mode.
2. Select the ground by clicking  RMB  on it.
3. Activate the scale tool by pressing  S .
4. Type  7key  to enlarge the ground 7x.
5. Press  Enter  or  LMB  to confirm and exit the scale tool.

Scaling with a Pivot

Suppose you want to shrink the house by 50%. As you can probably guess, this would be done with the scaling tool. However, if you did so right now without the right pivot point, the reduced house would no longer rest on the ground (check this by selecting the house and scaling it to 0.2). Blender scales (and rotates) objects around a pivot point, which by default is located at the median point (geometric center) of the selected object(s).

In order to scale the house while keeping its base on the ground, you need the pivot point to be at ground level. Since the 3D cursor is at ground level, you can do this as follows:

Origin to 3D Cursor Menu Item.

1. Make sure Blender is in Object Mode.
2. Select the house by clicking  RMB  on it.
3. In the 3D View header, click  LMB  on menu item "Object" and put the mouse cursor over Transform and select Origin to 3D Cursor from the pop-up menu. This can also be done with Ctrl+Shift+Alt+C, select Origin to 3D Cursor from the pop-up menu. (A.K.A. select "Object" which is just left of where you've been going into object mode/edit mode, as shown in the image. So Object>Transform>Origin to 3D Cursor)

The origin of the house is now at the center of the 3D cursor. If you scale the house, the place where the 3D cursor is located will remain fixed, and everything else will expand or contract from that point. The pivot is marked with an orange-filled circle. Do not mistake it for a selected vertex.

Edge Selection

It is often useful to select edges instead of vertices.

The select mode buttons.

1. Make sure Blender is in Object Mode.
2. Select the house by clicking  RMB  on it.
3. Press  Tab  to enter edit mode.
4. Click  LMB  on the Edge select mode button in the 3D View header.

In Edge select mode, edges appear as orange or white line segments when they're selected and as black line segments when they're not.

Just as you selected vertices in Vertex select mode, you can now select (and deselect) edges in the same way as vertices. This is also the same for Face select mode.

If you have difficulty selecting particular edges with the mouse...

It may be because those edges are doubled. This can happen if you cancel an extrude operation and forget to undo the duplication. Here's a solution:

1. Switch to Vertex select mode.
2. Activate a 3D View window.
3. Select all vertices by pressing  A  once or twice.
4. Press  W  to bring up the "Specials" menu.
5. Choose Remove Doubles.

Extruding Edges

You can extrude edges in much the same way as you extrude vertices.

Step 5

To add an overhang to the roof of your house, first move the pivot point to the peak of the roof:

1. Switch to Vertex select mode.
2. Select just the vertex at the peak of the roof.
3. Press  Shift + S  to bring up the Snap menu.
4. In the Snap menu, choose Cursor to Selected to move the 3D cursor to the peak.
5. Use the "Pivot" menu (located to the left of the 3D Manipulator button) in the 3D View header to change the pivot to "3D Cursor".

After step 2

Now extrude by scaling from that point:

1. Switch to Edge select mode.
2. Select just the four edges at the base of the roof.
3. Press  E  to activate the extrude tool. The effect is that you have just made a copy of the four edges.
4. Press  S  to scale the four edges uniformly from the pivot point.
5. As you move the mouse pointer away from the pivot point, the roof of your house will expand.
6. When the roof is the size you want, confirm by  LMB  (or pressing  Enter ).
7. Press  CTRL + SPACE  to toggle the manipulator on then make the overhangs slanted by holding  LMB  on the blue arrow that appears in the center of the house, and dragging down.

After step 7

Face Selection

It is often useful to select faces.

The select mode buttons after step 2

1. Make sure you're in Edit Mode on the house.
2. Click  LMB  on the Face select mode button in the 3D View header.

In Face select mode, the center of each face is marked with a small square. Faces appear as orange or stippled grey areas with orange edges when they're selected (depending on which face is active), and as grey areas when they're not.

Just as you selected edges in Edge select mode, you can now select (and deselect) faces:

• If any faces are selected, press  A  to deselect all faces.
• If no faces are selected, press  A  to select all faces.
• To select a single face (and deselect the rest), click  RMB  (or  Cmd + LMB ) on the center of the face.
• To toggle the selection status of a face (without affecting the rest), click  Shift + RMB  on the center of the face.

The three faces on the +X side, selected

Use these techniques to select all three faces (two roof and one wall) on the +X side of your house, as shown.

• Remember that the positive direction of the axis is the direction the arrows point to.

Extruding Faces

Just as you extruded edges to grow the roof, you can extrude faces to grow the entire house.

After step 6

To double the size of your house without changing the pitch of the roof:

1. With the three faces on the +X side selected, activate a 3D View window.
2. Press  E  to activate the extrude tool.
3. Press  X  to extrude along the X axis
4. As you move the mouse pointer in the +X direction, the +X half of your house will expand.
5. Press  2  to expand by exactly 2 Blender units. (If you scaled your house earlier, you must change this value accordingly, e.g. scaling by 50% means you press  1 .)
6. Confirm and exit the extrude tool by clicking  LMB  (or pressing  Enter ).

Deleting Edges

After step 2

If you look closely at the model, you'll notice an extra edge, inside the house, connecting the seams between the two halves of the roof. To delete this edge:

1. Edit the house object in Edge select mode.
2. Select just the edge you want to delete.
3. Press  X  or  Delete .
4. When the "Delete" menu comes up, choose Edges.

Deleting an edge automatically deletes any face(s) that include that edge.

Subdividing Faces

In order to add openings such as doors or windows to the walls of your house, you'll need to subdivide the wall (vertical) faces into smaller faces.

After step 2

To subdivide each wall face into a 10x20 grid:

1. Make sure you are not in wire-frame mode (otherwise the occlude hidden geometry button will not appear)
2. Edit the house object in Face select mode.
3. Select all six wall faces of your house.
4. Press  W  to bring up the Specials menu.
5. Choose Subdivide.
6. Set the number of cuts to 9 in the Operator panel (also accessible through F6).

In some versions of Blender older than v2.70, there may be a bug that prevents the subdivide function from operating properly.

You might be wondering why to make 9 cuts instead of 10, the reason is that in case of dividing a finite surface along one axis there will be always n-1 cuts to generate n single faces. Here the number of cuts is applied in 2 dimensions. So, if you count the number of faces on the subdivided walls, you will find a 10x20 grid. The reason why there are 20 faces instead of 10 lengthwise is because you doubled the size of the house along the X axis (lengthwise).

After step 6

Step 2

After step 3.2

Now you can extrude windows and doors:

1. Edit the house object in Face select mode.
2. Turn on the "Limit selection to visible (clipped with depth buffer)" (for old Blender versions "Occlude background geometry") option by clicking  LMB  on the toggle button in the 3D View header.
3. For each wall of the house:
   1. Go to the perfect view for that wall:
      •  Num1  for "front"
      •  Ctrl + Num1  for "back"
      •  Num3  for "right"
      •  Ctrl + Num3  for "left"
   2. Select faces where you want to create a window or door. An easy way to do this is by:
      1. Deselecting all faces by pressing  A  once or twice.
      2. Pressing  B  to activate the Border Select tool.
      3. Clicking and dragging  LMB  to delimit a rectangular area.
      4. After you release  LMB , all faces in the rectangular area will be selected.
   3. Press  E  to activate the extrude tool.
   4. Extrude inward 1/10th of a BU by typing  -.1  and confirming it with  Enter  or  LMB .

Final Steps

1. Adjust the position of the lamp and aim the camera until you obtain a good render.
2. Save your work!