Blender 3d tutorial
NOTE: In this tutorial, just like nearly all of my tutorials, I have provided what I call keystrokes lines. These are highlighted throughout the tutorial and are meant to allow you to see the actual keystrokes that I went through in order to get the results I get in the tutorial. More advanced users should be able to go through a tutorial without the keystrokes lines assuming I have explained myself sufficiently.
The main reason for having shape keys is so that you can take one shape and manipulate it without losing the original shape. Thats why its great for facial expressions. However, another use for shape keys can be in an animation where you have an object that is constantly changing from one thing to another and back again (Transformers comes to mind). All you have to do is model the first object, save it as a shape key, then edit your first object to something different and set another shape key. Then you can flip between the two throughout your animation. You can even add a third, fourth, fifth, and more if you like. Below is an example.
To keep things simple and not spend a bunch of time modeling something fancy I am just going to use a cube as the object that we are going to morph. If you would rather use something different, feel free to. You are not constrained to any one object for this. To start, if you have the default cube opened in Blender you can keep it, if not add it (of your object) to the scene. Since we are not going to be doing any extensive modeling in this tutorial, the cube is going to be our basic shape.
In order to set the cube as the basic shape, we need to set the Basis shape key. To do that, go to the Object Data settings in the right side of the screen. One of the sections that pops up is labeled Shape Keys. With the Cube selected, click on the plus sign in that section. A key named Basis should appear.
Select the cube, Go to Object Data settings, Go to Shape Keys section, Click on the plus sign
Now we want to set the state of our altered cube. When editing your cube into the morphed state you should keep one thing in mind. You cannot add or remove any vertices or you will also effect the basis state of your object. This is because shape keys keep track of the positions of the vertices and if one disappears it does not know how to animate that, so it removes it from all of the shape keys for that object. Basically, we need to keep everything intact assuming you do not want an altered basis object.
For my second shape key I am just going to stretch out the cube like I did in the image at the very beginning of the tutorial. Before we edit the cube, we have to go into the Shape Key settings again and add another key. Then we jump into Edit Mode, make all of the changes we want. When we go back into Object Mode, you should see the cube become a cube again.
Go to Shape Key settings, Click the plus button, Edit Mode, Edit the cube, Object Mode
Ok, maybe you arent convinced that it worked right. To test it out, make sure that Key 1 is selected in the Shape Keys settings. Below that box, you should see a setting labeled Value. If you slide that from 0.000 to 1.000, as you do it, you should see the shape begin to morph in the Key 1 shape. This allows you to have the cube at any morphed point between the original and Key 1.
Shape Key settings, Select Key 1, Play with the Value slider
But what if we want to go beyond Key one and make our cube even longer? One way would be to add another shape key, but there is no reason if we already have a key stretching in the same way. Instead of adding a new key we just need to edit the Max setting under Range in the Shape Keys settings to something larger than one. You can also change the Min value to allow negative numbers. These two numbers are the max and min numbers in the Value slider we were just playing with. Go ahead and change those values and play with the slider to get a feel for how that works.
Shape Key Settings, Change Max and Min Values, Play with the Value Slider
Aright, its time to stop messing around and to start animating our morphing cube. The first thing I want to do is change the Blender layout into the Animation layout. You can find the presets for this at the top of Blender directly to the right of the help menu. In that dropdown select Animation.
Change layout to the Animation preset
Animating this is quite simple. First, you will probably need to find your way back into the Shape Key settings. Select Key 1 and set it to the value you want your cube to start out at. When you have done that, right click on that Value bar. One of the choices should be Insert Keyframe. Choose that one. Then move go to slide 25 in the timeline. You can either right click in the timeline itself or change the setting manually. After that, change the value in the Shape Key settings and add another keyframe. When you have finished that, you should be able to play your animation and watch your cube go from the first state to the second state that you just chose.
Set Key 1 value, Right Click on Value bar-->Insert Keyframe, Go to frame 25, Change Key 1 value, Right Click on Value bar-->Insert Keyframe, Test your animation
If you decide you want to edit the animation, you can always look at the Dope Sheet and the IPO curve editor, both on the left hand side. The top one is the Dope Sheet. This is where you can change the location of the keyframes for anything that you have animated. Below that is the IPO curve editor, you can see each of the keyframe for everything you have animated here as well, but the difference is that you can edit the curves similar to the way you would edit a Bezier curve. I wont go any deeper into those than that because I think the best way to figure out how those work is to play around with them and see what happened.