industriousOne

Where I size my starting shape — a box — to the exact dimensions of the car, and mirror it.

Will consider one Blender unit to be one meter. This, best I can discern, gives me a maximum resolution of 1mm, which should be fine for my purposes. If you needed better resolution, scale up.

Splitting the Box

Cars are laterally symmetrical — the left side is the same as the right — so I can save myself some work by modeling just one side. I can set this up right from the start by splitting Blender’s default starting box in half and applying the mirror modifier, so that changes made to one side are automatically applied to other. To split the box, I’m going to use the Knife tool, which I expect to be using a lot when I get to the mesh refinement stage.

We’re editing, so make sure you are in Edit Mode (TAB). We need to edit the entire box, so make sure that “Limit selection to visible” is turned off (that’s the cube next to the vertex/edge/face selection buttons).

(put an image of the “limit selection” button here)

In the top view (the view with the X-Z axes), select the entire box (AKEY for “select all”). Press KKEY to bring up the Knife menu. Choose “Knife (Midpoints)”, since we want to slice the box right down the middle, and then click-and-drag a line right down the middle of the box, from top to bottom. The line does not have to be exact. Press ENTER to make the cut.

Now select everything on the left half of the box (BKEY and drag). Press XKEY to delete and choose Faces. You should now have one half of the original box, the left side of which is open.

Mirror the Box

Switch to Object Mode (TAB). The box should switch to a pink outline to show it is selected; if not, select it now.

Switch to the Edit Buttons ((image) or F9). On the Modifier tab, choose “Add Modifier”. Select “Mirror”. You should now see two boxes in all views, replacing the half that we cut off earlier. Select “Do Clipping”, which will make sure that we don’t accidentally move any vertices over the mirroring axis.

Sizing the Box

This is getting long…I should split it into multiple pages

The process to place vertices exactly is as follows: select the vertices to move. Press GKEY to grab them. Press XKEY, YKEY, or ZKEY to constrain the move to a particular axis (you can use the little axis diagram in the bottom-left corner of the view to help decide), then type in the distance to move the vertices along that axis.

Before starting, make sure that you are in vertex select mode.

I’ll start by resizing the box to the length of the car: 4639mm, or 4.639 meters. Switch to edit mode, and put the cursor in the side view. Press BKEY to start box-select mode. Select the two vertices on the right side. Now press GKEY to “grab” them. Press YKEY to constrain motion to the Y-axis. Then type “-1” and ENTER to move that side back to the origin. Now, press GKEY and YKEY again, and enter one-half the length of the car, which in my case is 2319.5mm, or 2.319 meters, so I enter “2.319” and ENTER. Finally, press AKEY to deselect the vertices.

Repeat the exact same procedure for the left side of the box, but reverse the sign of the numbers (replace positive numbers with negative, and vice versa). Then move onto the other views, and repeat the process for the width and height (using the front view).

Now might be a good time to use the mouse wheel in each view to zoom in a little. Press [F12] to render your new vehicle. Swanky!

Thanks for Robert Burke and BlenderArt Magazine #11 for the tip on exact vertex placement.