Saturday, February 27, 2010

A Sketch of a Swimsuit Model

Saturday, February 20, 2010

Animating Hidden Keyable Attributes

When taught to animate in Maya, we tend to become very comfortable with the channelBox, but the channelBox only offers a small portion of all the attributes we are able to animate. The keyable attributes you see in the channelBox are usually only the most common ones available to you. In this tutorial, I will describe how to locate, setup, and animate the color attribute on an object that has a Phong shader connected to it. After acquiring this knowledge, I encourage you to experiment with other keyable attributes. In a later edition, I will show you how to animate non-keyable attributes.

Let's start out by creating a simple NURBS sphere on the stage and by pressing 5 on your keyboard so you can see the sphere shaded gray. What you see is a default Lambert material that is assigned to NURBS objects at creation. Let's right click the sphere and assign a new Phong material to it. Open your Attribute Editor by pressing Ctrl+a and find the phong1 tab. Make sure your playhead is on frame 1 because we're about to key a color. Locate your color attribute in the Attribute Editor under the phong1 tab. Right click it, then click on Set Key.

At this point, it appears nothing has happened. There is no red tick on the timeline and Maya did not alert you of a change. If you look to the right of the color slider, the checkered box turned into the input symbol. If you click it, you'll see that the color attribute is now an input to an animation curve!

After clicking the input symbol, you should be on the phong1_colorR tab of the phong1 Attribute. Under the Keys section is a charted version of the keys you set on this curve. This isn't too user friendly so let's bring this up in our Graph Editor. Wait a second? We need to be able to select this object before the Graph Editor can load it... that means we'll need to open up our Hypergraph so we can find and select the object.

Select the sphere you created and go to Window:Hypergraph:Connections. Find and select the phong1SG (read: phong shader group.) Let's graph the input connections by navigating to Graph:Input Connections. Viola! You are now looking at phong1_colorR, phong1_colorG, and phong1_colorB. You can select them and they will appear in your Graph Editor. You are now able to modify the curve as you see fit and best of all, since it's a color that you're animating, you get an instant preview in your viewport.

To finish the exercise, hold k+LMB and click on frame 24 inside the GE. Hold i+MMB to insert a key. Now press w, select the key you just created and move it up to give it a value of 10. You have just created a glowing light. Select Curves:Post Infinity:Cycle to give it a pulsating effect.

I hope you have found this tutorial useful. Please experiment with this technique and share your experiences.

Speed Painting: Screaming Crazy Man

Thursday, February 18, 2010

Vimeo Switch

Blogger has been experiencing some drama with their video servers. It has been over a month since the problems started so I decided to switch over to Vimeo for their video services since they seem more realiable. Stay tuned for more animated videos!

You can visit my page on Vimeo by visiting

Friday, February 12, 2010

More On The Graph Editor

Being able to buffer curves and having the ability to mute/unmute tangents are useful tools when refining an animation. Using these tools along with ghosted frames and motion trails (to check spacing and arcs) will give you the tools you need to create high quality shots.

Let's say you had an animation of a bouncing ball (and who doesn't?) In this animation, you probably are using more than one animation curve so it should suffice for this example. You are able to temporarily silence curves that are interfering with your motion by selecting the channel(s) in the graph editor and muting them. This will cause the curve(s) to flatten out and behave as though there were no keys set on them.

You can find the mute item under your Curves menu of your graph editor.

Using our simple bouncing ball example, you can try muting your horizontal anim curve so you can focus on the vertical motion of the ball. Conversely, if you wanted to focus on the rolling and settling of the ball, you could then mute the vertical motion. If you were swinging a pendulum in a figure 8 motion, the same rules still apply.

When muting a curve in the graph editor, there will be a little symbol next to the channel indicating that it has been muted. The original keyed anim curve will become a dotted curve and the temporary replacement will become a flat solid line. You can unmute the curve(s) from the Curve menu in your graph editor.

Handling one dimension at a time by muting channels you temporarily don't need is useful but sometimes this isn't enough to help you tweak efficiently. At times, you need to edit two or more channels at once and when this happens, your arcs and spacing become priority.

To check out your spacing, go under your Animation menu set and under the Animate menu, you'll find the Ghost Selected item. Go ahead and reset the settings one by one based on your situation. I usually like having 2 keys ghosted after and 1 key ghosted before. Or having two steps ghost after and 2 steps ghosted before.

Once your spacing is neatly arranged, you will want to double check the arcs that your objects are moving in. Do this by switching on Motion Trails. You can also find this one under the Animation, Animate menu. You can have it update when you change a key--you can also have different display styles for the tool. My favorite display style is the line type because it visually plays "connect-the-dots" with all my keys.

As far as I know, there is no magic "remove motion trail" button. However, you can delete the trail by selecting it and pressing delete.

Using Buffer curves can be a life saver. As animators, we're used to having multiple files for the same scene and sometimes this is true even if there is a minor tweak on a curve. Buffer curves can make your work more efficient by allowing you to test out different key configurations without throwing away all the hard work you put in.

Before you use Buffer curves, you need to switch them on in the graph editor view menu.

Once you are ready to tweak an anim curve and turned on Buffer curves from the view menu (in the graph editor), you can select the curve and go to Curves->Buffer Curve Snapshot. This "saves" your current configuration for your current maya session. You can now start tweaking until you can't tweak anymore. You'll be able to see the original curve ghosted in the back but if you don't like what your new curve is doing, you can always go to Curves->Swap Buffer Curve.

A small note on weighted vs. non-weighted tangents: I disagree that it should always be one or the other. I think it's fair to say that it's best to use the right one for the job. I generally start out with non-weighted tangents but if I find my particular situation better fitted for weighted, then I will switch to weighted tangents.

A pro of weighted tangents is that they require less keys since they use different math to interpolate the curves. A pro with non-weighted tangents is that they can scale uniformly without a fuss.

A con of weighted tangents is that they do not always behave when you scale them. Sometimes the tangents reset and act funny especially if you have stretched too much. There is plenty round off error to pull this off successfully. A con of non-weighted tangents is that they require more keys to do the same thing a weighted tangent can do.

I hope this follw-up tutorial has been helpful.

A Cute Cat Girl

Thursday, February 11, 2010

Graph Editor Tangent Types Explained

Some of us have become overwhelmed with all the tangent types that exist when we first meet the graph editor in Maya. Knowing when to use what type of tangent and which tangent type is preferred is often baffling. However, I feel that if you understand the differences between the tangents themselves, their purpose will all become clear. The following few paragraphs describe tangent types in simple terms. I hope this is useful for those that are quietly wrestling with your anim curves.

Spline, linear, and stepped tangents are the 3 basic tangent types. One uses zero interpolation between keys: Stepped Tangents are good for blocking. Another tangent type interpolates evenly (linearly) from one key to the next: Linear Tangents. And finally, the other basic tangent smooths all the paths between keys. These are the Spline Tangents.

The Flat Tangent is good for peaks and valleys of your curves... if you want to prevent a spline value from not overshooting, you can set it to flat. This will ensure that the highest or lowest value is the highest or lowest value between affected keys.

The Clamped Tangent is a mixture of flat and spline tangents. The clamped curve is all spliney, however, there is one exception. When two consecutive keys share the same value, they will automatically "clamp" by flattening out. This is usually used for holds... like when you have a footstep that needs to stick. The foot shouldn't move from its position until it comes off the ground.

Finally, my favorite one is the Plateau Tangent type because it is like a clamped tangent on steroids. Unlike clamped tangents, it will flatten out the first and last keys. Any keys in between a peak or valley will be treated like a spline. I like to set this type as my default.

I hope this clarifies a few things for those that were struggling with tangent types. Please leave a comment if you want to discuss the graph editor further.

Tuesday, February 2, 2010

Monday, February 1, 2010

Useful Maya Hotkeys & More Hidden Menus

Welcome to the month of February! I'll start this month off by talking about important hotkeys that I use when working in Maya. I recommend using hotkeys because I believe in spending more time with your work and less time in the menus. I originally wanted to include a few of the most frequently used hotkeys but let's face it, Maya isn't Microsoft Paint. It is huge! I didn't even get to go into the hotkeys for Artisan, the Graph Editor, or even the all-important Outliner! These are core components of Maya and I should cover using them in the future.

Make These Basic Hotkeys Part of Your DNA
To the left of your backspace key, you have your - and your + keys that adjust the size of your current manipulator. Adjust your manipulators when geometry gets in your way. Parent things using p and unparent them using shift+p. Duplicate objects using ctrl+d. Press h to hide selected objects and press shift+h to show selected objects. The 4 key displays your objects in wireframe while 5 displays them in shaded mode. Press ctrl+g for creating a group of objects or deselect everything to create an empty group. Empty groups are super useful but that's a topic all on its own.

One of my favorite things in Maya is the ability to toggle UI elements and going into fullscreen mode by pressing ctrl+space. Toggle back by using the hotkey again. The a key frames all objects while the f key frames selection. If you hold shift while using these keys, it will do this operation in all your current views.

The q key is your selection tool. This is an important tool because it doesn't let you do any harm. It only allows you to select things. I find myself using q often when I simply want one of the w, e, or r manipulators to disappear.

Temporarily hide everything around the currently selected object by pressing shift+i. To get everything back, deselect the object and press shift+i again.

Make Animation Hassle Free By Learning These Hotkeys
The alt+v combination plays and stops your animation while alt+shift+v rewinds it. The , key goes to previous keyframe while the . goes to the next keyframe. If you hold alt while using hotkeys, you will step one frame at a time. Use k+LMB to use an awesome the time dragger tool. Press alt+b to cycle your background color in the viewport. Keyframe your translates by pressing shift+w, key your rotation by pressing shift+e, and finally, key your scale by pressing shift+r.

[This would be a good time to take a break and try out some shortcuts if you are new to Maya.]

Another Hidden Marking Menu
When I first fire up the program, I usually get a blank grid. If I were to start modeling, I would need some geometry on my grid so the first thing I would do is hold shift+RMB gesture down in the viewport. This will create a polyCube for me. If you want to go back to that (context sensitive) menu, you'll have to deselect the cube (and everything else you have selected) and drag your RMB to see what else is there. This is the rapid fire way to create geometry. There are a few more hidden menus, but I'll save these for future posts.

Try These Hotkeys Out While Editing Objects
I like using F8 to go into component mode, but you can get even more specific by using F9 to dive into vertex mode, F10 for edge mode, and F11 for face mode. You can also use < and > to shrink or grow a selection of a component.

Switching menu sets can get clumsy so I use my hotbox for all menu sets. Press space to access this baby. It's the quickest way. Other ways to get to your menu sets are to use the F2-F5 keys to switch the sets or use the h+LMB marking menu. Give it a shot and see which one you like.

Snapping can come in handy especially when snapping with MMB. Using MMB instead of LMB allows you to click and drag anywhere on the viewport instead of being forced to use the manipulator. Snap to grids by holding x, snap to curves by holding c, and snap to points by holding v.

A Final Word
I should have known this tip was going to be lengthy--I even cut a bunch of stuff out. Either way, please communicate what you would like for me to explain if something doesn't work out for you or if something isn't clear. I know these hotkeys are in the numbers, but I encourage you to try them out. It is worth the effort to memorize these because your workflow will improve dramatically if you cut out all the menu searches down to a single key combo.