This tutorial assumes you are a Blender beginner and includes detailed steps that describe how to add a texture to a mesh and render it so it looks as much like the original image as possible.
Note: The screenshots and descriptions were based on version 2.49 of Blender. The workflow is different for more recent releases of Blender.
01) Start Blender.
02) Hit the Delete key on your keyboard (the key below Insert) to remove the default cube object in the scene. Alternatively, you may hit the X key on your keyboard.
03) Left Mouse Click on the Erase Selected Object(s) menu.
04) Hit the Spacebar.
05) Choose Add -> Mesh -> Plane
06) Hit the N key on your keyboard.
A Transform Properties panel will appear. We will scale the mesh so it matches the overall aspect ratio of the original image. This is important so we avoid distorting the image.
We will be changing the ScaleX and ScaleY items so they match the aspect ratio of our image. In this example we will be UV mapping a 640 x 480 image to the plane. This is a 4:3 aspect ratio.
07) There are several ways to change the ScaleX and ScaleYvalues. Here are three ways to do it:
a) Double-Click the ScaleX item and type in 1.6.
b) Hold down the Shift key and Left Mouse Click on the ScaleX item and type in 1.6.
c) Use the small right-pointing triangle on the right side of ScaleX. Each click will increment the ScaleX value by 1/10th.
08) Use the Tab key on your keyboard to select the ScaleY value, and enter 1.2 for it.
09) Hit the Enter or Return key (on your main keyboard) for the changed values to be processed. You should se something similar to the following:
Note: If you type a value in the Transform Properties panel and you can't seem to deselect something, hit the Esc key.
10) Hit the 0 (zero) key on your numeric keypad. This will switch the viewport to camera view.
11) Hit the Home key on your keyboard. This will show every object in the current scene. You should see something similar to the following:
Currently, the plane we added is selected. You can tell it is selected because its outline is pink. We need to choose the camera and reorient it so it shows the plane in the viewport.
12) Select the camera object by Right Mouse Clicking on the camera object. It will turn pink when it is selected. Refer to the image below as a reference.
You will also notice that the values in the Transform Properties panel have changed to reflect the current values of the selected camera object.
We are going to reset the camera's position and orientation. To do this we will "zero out" the LocX, LocY, LocZ and RotX, RotY, and RotZ values.
As with most features in Blender there is always more than one way to do the same thing. The steps below will help you understand an important method for changing the values in the Transform Properties panel. Right after step 17 you will see a much faster way to "zero out" the camera's position and orientation using hotkeys.
13) Hold the Shift key on your keyboard and Left Mouse Click the LocX item. The number values will be highlighted in light red.
14) Type a 0 (zero) for its value, then hit the Tab key on your keyboard.
15) Type a 0 (zero) for its value, then hit the Tab key on your keyboard.
16) Repeat step 15 above for the LocZ and RotX, RotY, and RotZ values.
17) Hit the Enter or Return key (on your main keyboard) for the changed values to be processed.
Shortcut Method for the above 5 steps:
With the camera object selected:
a) Hit Alt + R, then click Clear Rotation, or hit the Enter or Return key on your main keyboard.
b) Hit Alt + G, then click Clear Location, or hit the Enter or Return key on your main keyboard.
You can clear any object's rotation or scale using the above hotkeys.
Next we need to move the camera up on the Z-axis so our image will be framed within the camera view. If you click on the Z-axis manipulator for the camera it constrains the location of the camera to an "up" or "down" position
18) Move the camera up by holding the Left Mouse button on the blue "arrow tip" manipulator of the blue line that points up from the camera, and drag up, so the camera is above the plane object. Refer to the image below for a reference.
Note that a LocZ position of the camera should be approximately 3.6 (or something close to that). You can enter this value in the Transform Properties panel if you want to be more precise.
19) Hit the 0 key on your numeric keypad to switch the viewport to the camera view. You should see something similar to the following:
20) Hit the N key on your keyboard to hide the Transform Properties panel. We won't need it anymore.
Note: Your mouse pointer must be within the viewport window (the window with the grid and your artwork) for the N key step above to work. Blender is not only context savvy, but it makes decisions internally as to what options are available based on the location of the mouse when you choose a keyboard hotkey command.
The light gray rectangle inside the dotted black lines in the center of the image above is the plane object we added earlier.
Note: Repeatedly hitting the 0 (zero) key on the numeric keypad will toggle your viewport display between the camera view and the last view position and orientation prior to choosing the camera view. Try it out, as it is extremely useful.
21) The scroll wheel of your mouse will zoom your viewport in or out. Try it out, then zoom in so the outer frame of the viewport fills the screen.
Next we will need to split the view so we can more conveniently see the UV/Image Editor window.
22) To split the window, move your mouse to the black "seam" between the top and bottom windows in the Blender interface and Right Mouse Click when the cursor changes to a double-ended arrow.
Choose Split Area. You will see a gray vertical line that follows your cursor along the viewport area of the window as you move your mouse left or right.
23) Left Mouse Click to choose the location where the split should occur. When you are finished you should have a layout similar to the one shown in the image below:
Next we will change the newly split window area so it shows us a representation of the image we will map to the plane object.
24) In the lower left area of the new window area, change the window type to UV/Image Editor. Refer to the image below.
25) Right Mouse Click on the plane object so it is selected. It should have a pink outline around it.
We now need to switch to Texture Paint mode so we can apply a bitmap texture to the plane object's mesh.
26) Make sure the plane object is selected, then choose Texture Paint from the window mode of the main viewport window. Refer to the image below.
27) Hit the Tab key on the keyboard. This will select the entire mesh object so an image can be mapped to it. You will see something similar to the following, where the face of the mesh object and the area where the texture will go are shaded with a fine grid.
Now we will load the image into the UV/Image Editor.
28) In the UV/Image Editor window, go to the Image item at the bottom of the window and choose Open... from the menu. Refer to the image below.
Now we need to navigate to the location of an image to map to the plane. The image that matches the example in this tutorial is shown below. Right-Click on the image below in a web browser and choose Save Image As... to save a copy of the image to your local drive. You should make note of where you save the image, as you will need to know its location when you import it into Blender.
29) Choose the image to open by Left Mouse Clicking an image file from the file selector list on your computer, then Left Mouse Click on the Open Image button to import the image to the texture you have set up. Refer to the image below.
Note: It may take a bit of practice to get used to seeing the files on your computer in the way that Blender shows them. Since Blender works on all major operating systems it needs a consistent way to browse for files, irrespective of the standard "look" that each operating system has. Once you get used to browsing for files the Blender way you will be much more familiar with the location of all of your computer's files, and you may find that this "deep file location" knowledge is helpful for other kinds of non-Blender work.
Note also that if you hold down the Control key before clicking Open... from the UV/Image Editor menu window (as described in step 28 above), that you will be able to view thumbnails of any images that Blender recognizes in the file selector window.
Once you have opened a texture you should see something similar to the image below:
Next we will change the viewport shading display so it shows the texture as it looks when it is applied to the mesh, in real-time.
30) In the main viewport window choose the Viewport Shading type menu and choose Textured. Refer to the image below.
You may now do anything you like to the Plane object and the texture will stretch or "flow" with it.
The last thing we will do before rendering the scene is set material properties for the texture so it looks as much like the original image as possible.
31) Choose the Shading panel from the Buttons window at the bottom of the screen, or hit F5. Refer to the image below.
32) Add a new material to the object by clicking the Add New button in the panel. Refer to the image below.
Once you add a new material you will see the panel change to something like this:
We need to change of couple of material properties to get the image to look better when rendered.
33) In the Material tab click the TexFace and Shadeless buttons. Refer to the image below.
The above material settings tell Blender to render the texture that is applied to the face of the plane object, and to display the texture with no shading properties. This means that lights and other material settings won't change the look of the image, and it will appear nearly identical to the way it would look in a bitmap editing program like GIMP, or Photoshop, yet it is in true 3D space so you can manipulate it any number of ways.
All that is left to see the results of the above steps is to render the image. However, it's probably a good idea to save the Blender file we just made first.
34) To save your Blender file type Control + W to "Write" out the file. You will need to navigate to a save location you can easily find. To go up to a higher view of your files you can click the P button when the file save window is open. Each time you click the P button you will move higher and higher up in your view of your computer's files and directories. It may help you to move to a more familiar location when you save your Blender file. Click the Save File button once you have named your file and chosen a save path for it. Refer to the image below.
Now let's render the scene.
35) To render the scene you may hit (F12), or go to the Scene panel (F10), and click the Render button. Refer to the image below.
You should see the rendered image appear fairly quickly, as this type of render doesn't require any heavy lifting from the computer.
The render panel has many options that you can try out to see the results of different settings, so check out those pretty buttons in the render panel. One setting you might try disabling is the OSA (oversampling) button. Oversampling, otherwise known as antialiasing, smooths the appearance of fine lines (maybe wrinkles too), but may not be desirable if the UV texture image appears too soft when rendered. If you use oversampling, the defaault OSA value of 8 is usually good. Otherwise, for this exercise try rendering with OSA disabled to see if the image appears sharper.
36) If you want to save your rendered image to disk you have two options:
a) In the User Preferences header at the top of the main viewport window select File > Save Image…
b) Hit F3.
The image format for the rendered file is determined by the file output setting in the Format tab (above). By default it is set to JPEG, though you can save your rendered images in any number of standard professional formats such as PNG, TGA, TIF, GIF, and even OpenEXR, a high-end film and video file format developed by Industrial Light & Magic.
Now that you know a bit more about how to apply a texture to a mesh, you are more familiar with a few more of the snowflakes that sit atop the giant iceberg of graphic creative potential that is Blender.