Introduction

This lesson was about exploring set driven keys in Maya.

A set driven key is used to link objects in maya, so that one objects attributes are influenced by another object’s attributes. They are used within the Set Driven Key window.

Research Task

The next task was to research set driven keys. Here is some information I found:

Set driven keys can be used to make the animation process simpler and faster in Maya. For example, applying set driven keys to a character model, and then a door model will make the character model a ‘driver’ key and the door model a ‘driven’ key. The translate Z attribute of the character model can be linked to the translate Y attribute of the door model, so that when the character is animated moving towards the door on the Z axis, the door opens by moving on the Y axis. This technique can also be used to make character’s muscles move, or a set of clockwork gears for example.

Doorway Practical Task

The next task was to follow along with the tutor’s demonstration to try out the Set Driven Key function in Maya. I was given a Maya scene of a door with some controls, that I would animate using set driven keys.

To do this, I started by changing the interface to animation and then going to the Key menu, Set Driven Keys and then the Set… menu. This opened the set driven keys window.

From here, I selected the handle which was going to open the doors, and then pressed the load driver button in the menu.

I then selected both doors and pressed the load driven button. Now, the attributes of the handle were connected to the attributes of both doors.

Next, I rotated the handle to where I wanted it to go in order to open the doors, and then used the move tool to move the right door to where I wanted it to open to. In the set driven keys menu, I now selected the rotate Z attribute of the handle, and the translate Z attribute of the door (since I wanted the door to move along the Z axis) and hit the Key option. Now, when I rotated the handle of the door, the right door would slide open.

I then repeated this process for the left door, rotating the handle and moving the door to the positions I wanted them in, before selecting both attributes in the window and choosing the Key option. Now when I rotated the handle, both doors would open.

Here is a playblast animation of the outcome:

Hand Crank Animation

The next task was to use what we have learned about set driven keys to animate a crank turning a set of gears. To do this I followed a similar process as before, starting by modelling a crank using a cylinder and the extrude tool. I used the gear primitive for the gears and modified them a little bit, filling in the holes in the middle. I first applied the crank as the driver and the bottom gear as the driven, linking their rotation on the Z axis. I then moved the crank and the gear 360 degrees and keyed them together. I repeated this process for the top gear, this time using the bottom gear as the driver and the top as the driven, connecting their rotation and keying the rotation of the driver gear to the opposite rotation of the driven.

Here is the playblast below:

Conclusion

You can see in the video that the top gear stops turning before the bottom gear, and the alignment of the gears isn’t perfect, causing the gears to clip into each other a little bit. Next time, I would take a bit of extra time to check that my animation was more refined before creating the playblast.

Overall, today I learned an important technique for 3D animating, allowing me to speed up the process in my future work.