"kmFeatherConstraint" MEL Script {

Here's a little MEL script I wrote a while back. It creates a series of constraints down a chain of items with a falloff. A simple GUI allows for changing of ordering and falloff ease modes ( Linear, Ease-In, Ease-Out, Ease-In-Out ). Eased modes use S-curve interpolation for a nice smooth gradient.

There's a few things I'd like to add to make this better, but I thought I'd throw up version 1 and see if it's useful to anyone.

Here's a video demonstrating its use:


Download kmFeatherConstraint

"kmCurveBtwnPts" MEL Script {

I present a very simple, clean, and useful MEL script that does exactly what the name implies. Given a selection of objects, the script creates a NURBS curve that intersects with each point in the order they were selected. Additionally, the curve is constrained to the selected objects, so it will always go through every point.

This can be useful for a multitude of practical rigging setups, as well as just to add some simple flair to improve the visual interface for a rig. I'm excited to have this in my back pocket!

Here's a video demonstrating its use:


Download kmCurveBtwnPts

After much trial and error, I was able to find a simple and clean way to constrain Edit Points of a NURBS curve, so the curve follows through the control points. Edit Points (EP) are much less accessible than Control Points (CP), as moving any given EP has a much greater influence on the curve than a CP. In data they are just read-only vectors. But it looks much nicer to have the curve actually go through your control point, rather than just be influenced by it.

I used two useful tricks here that I'd like to highlight:

1. MEL command "eval()" interprets a given string as a command and executes that command. This allows me to iterative-ly compile my curve command, since a single curve command requires all the points to be known. Once I loop through objects, obtain my points, and add it to my command string, I can use "eval( $curveCommand )" to run it!
2. "pointCurveConstraint" is a very useful constraint that cleanly constrains a curve to an object. Constraining EPs is not possible, constraining CPs or clusters of them doesn't work either, and binding the curve to joints (my first approach) produces non-smooth and undesirable results. This solved all my problems!

-K

"Gauntlet" {

An old woodsman possesses an ancient gauntlet with the power to summon armor and weapons at will. This weapon is put to the test as he discovers that his gauntlet is not the only ancient magic in these woods.

Created by Jeff Belgum, Katlan Merrill, and Ben Smith Sound design by Jesse Rope Score by Anthony Ferraro and Zach Johnston

Finally it's done! Here is my thesis short film, entitled "Gauntlet". I had the pleasure of working with two other talented friends of mine, Jeff Belgum and Ben Smith. We all put a couple years of our lives into this project, and many late nights. We wanted to push the envelope of student films with stunning visuals and a dynamic action sequence. Even if we produced nothing, it would have been worth the first-hand knowledge of going through the process of making an animated film from start to finish.

Role {

My roles in the creation of this film were primarily in the pre-production section. I was the Lead Designer, Lead Modeler, and Lead Rigger, so I designed, modeled, and rigged the two characters, the "Hero" and the "Beast", in addition to helping with story, layout, simulations, hair, rendering, and animating. I also managed and automated parts of the pipeline to speed up workflow with MEL scripts, vrscene files, and program integration.

Beast {

The Beast proved to be the most complex and time-consuming rig. I got a bit creative with the control scheme, which made my rig unique and intuitive. The back controls are all exposed well above the actual model, allowing the animator to always select them from any camera angle. The custom control spline shapes were created in Illustrator, and each describe the action they perform. My goal with the rigs was to create the most automated, easily animated rigs possible, while maintaining a good amount of control. This led me to the decision, for example, to make the tail fully simulated, requiring no animation at all to look smooth and realistic.

I created my own muscle system for deformation at particular joints, like the shoulders, hips, and biceps. I had experimented with maya muscle, and due to the buggy and uncontrollable nature of them, decided to make my own. It is a simple system, taking 2 points as attachments, and based on the distance between them, bulges or stretches the NURB muscle object using user-created SDKs. Complete with a basic MEL interface, I was able to get decent deformation at all points with full customization and no bugs.

Hero {

The Hero rig gave me the challenge of incorporating Motion Capture into the pipeline. Using Maya's HIK auto-rigging features, I was able to get a decent rig that was Mocap compatible with relative ease. Given the time, I would have created my own rig and used HIK as an input. HIK is horrible to animate with and I don't recommend it. The challenge in this rig came with the armor (modeled by Ben Smith). I didn't have the processing power or time to simulate each piece of armor. This route is also bug-prone and takes a good amount of time to perfect. I instead decided to get creative and make the armor conform to the pose of the Hero. With a variety of tools, including SDKs, I was able to make the armor slide, pivot, and interlock to match all extreme poses. I was sure to add some controls to certain troublesome regions in case of any unforeseen tweaking that might be needed on a per-shot basis. All in all, the armor worked out quite well. Given more time, I would have added a bit of constrained jiggle simulation on top of them just to sell the effect.

Please comment if you'd like me to break down any part of the pipeline! I'd love to hear your input and questions!


-K

Crabs and Penguins Launches {

Finally the day has come! "Crabs and Penguins", a game I worked on this last year for Coca Cola, is finally available on the AppStore for iPad and iPhone. It will be releasing for Android, PC and Mac standalone soon. We also made a cinematic commercial of the story behind the game. Be sure to check it out at the website link below!

As lead programmer at Ember Lab, I was tasked with the game programming for the main 6 levels. This includes the player controls, player movement, collectibles and power-ups, graphics and shaders, level block-ins, and game-play testing. The primary development tools were Unity3D game engine with C# programming language. I also used some CG and ShaderLab for shader programming, as seen in my Water Shader post.

Screenshot of "Crabs and Penguins"

The game is free so if you have an iOS device, go download it and tell me what you think!

Here's the link to the Download, the Website, and the Facebook Page.

If you have any feedback, comments, or questions on how anything was done for the game, please comment below! I'd love to do a tutorial or explanation on how we made this game. Try to be specific so I can give you a detailed answer.

"Leave a crab. Return a hero."

-K

Soft Feet {

I'm currently working on adding details to a quadruped rig from my senior thesis film "Gauntlet". I didn't get as much time as I wanted rigging him, so I decided I'd enhance a few parts. One part that bothered me about this character was his feet's interaction with the ground. So I set out to fix it by adding deformation to the foot to simulate the pads squishing on the ground. The animator can get the foot relatively realistic and with minimal clipping, but having a touch of deformation sells the impact.

The simple approach would have been to just create some NURB deformers and give the animator control of the squash and stretch of the foot. However this would add even more work to the poor animator who is tasked with a walk cycle of a quadruped. So I decided an automated/simulated solution was ideal in this scenario.

Now I needed to avoid the messiness and expense of making the entire body into an nCloth. The body mesh is quite high poly, and I only wanted to simulate the feet. Thus, I decided to only simulate the pads of the foot and use those as influences on the main mesh. The pads are extremely low poly, so they simulate almost real-time. And they also more correctly describe the foot of a lion (my inspiration for the feet). The one trick here is to make sure you check on "Use Components" in the skinCluster of the main mesh being influenced. This means it will use the components of the influence object and not just its transform.

Here is a quick video showing the deformation effect:




And here's one on a more bumpy surface (it is simulated after all):


So, to replicate, follow these steps:

Water Shader {

Here's a quick demo of a mobile water shader I wrote for an Ipad game (I'll post it when it is released). I used Unity3D with ShaderLab and CG for the shader writing and C# for the scripts. I will try to package it and upload it to the Unity Asset Store soon so others can use it.


Features:

• Efficient shader optimized for mobile devices
• Realtime refraction of anything on opposite side of water plane
• Sin blend between 2 normal maps for smooth normal animation
• UV Panning normal maps
• Reflection Cubemap
• Renders in Opaque queue with no expensive transparency cost
• Separate settings for fog over and under water
• Separate settings for far clip planes over and under water (quality)
• Controls for Transparency, RefractionFactor, ReflectionFactor, RenderTextureSize, Tiling, FogSettings, etc

Here's some more screenshots and a video: (Sorry for bad quality)

And here's the relevent vertex and surface shaders (in CG):

So It Begins {

Today the blog begins! I will be posting cool tricks and interesting solutions on both Programming and Rigging topics as I learn them. I hope to use this blog as an informative and helpful resource to others in my field, and as a sample of my work.

I also reserve the right to stray a little from Rigging and Programming to show some of my work in Modelling, Rendering, Simulation and FX, and other 3D Art.

So please check back often! Hope you enjoy it!

-K