10/30/11

Cucurbita Maxima 2011

It's that time of year again where I take a tiny saw and start cutting into the skin of pumpkins.  Here are the final results for this year: Captain America and Red Skull.



To show the process of how the effect is achieved:



I had to put in Sarah's contribution to our holiday spirit:


10/28/11

Advanced Lighting and Texturing: The Haunted House

Now that the character Chimi is complete, we are supposed to be lighting an environment and compositing it together.  Typically you will only light an environment when the textures are done, but for this class, we are doing things a bit backwards.  We created an additional render layer with all of the scene objects in it and assigned a 50% gray lambert shader as a layer override.  That way, we can focus just on lighting the scene.


I decided to go with a creepy nighttime scene with a long green streak of light reminiscent of a hallway door opening onto a supernatural scene.  I also used Mental Ray's Final Gather for this rendering, which is a way of calculating how light bounces from one surface to another.  In addition, I added in the background plate after rendering, as well as an ambient occlusion pass to bring out the cracks and details of the geometry. As a final note, I duplicated the rendered layer in Photoshop, blurred it slightly, set it to a screen transparency, and then adjusted the brightness and contrast and opacity so that there was some slight glow to the lit surfaces in the scene.

There's a lot of texture creation that needs to be done for this and hopefully I will be able to get it out easily.

10/27/11

A Trip to the Ranch...



Today I had the wonderful privilege of visiting Skywalker Ranch in Marin County, California, thanks to my directed study advisor, Roger Ridley.  Roger works as an assistant technical director for Lucasfilm on a feature animation.  The company is split between two locations: Big Rock Ranch where the animation previzualization department is, and Skywalker Ranch where Skywalker Sound and a few other offices are located.  He took me on a tour of the beautiful campus and I was constantly wondering if I was at a visual effects company or at a really fancy reception center.  Here are a few things I learned on my trip that may or may not be true:

  • All of the security guards carry lightsabers.
  • The Ranch has it's own fire brigade.
  • Saying "This is not the Toyota Camry you are looking for," while waving your hand won't get you a laugh from the security guard at the gate.
  • The main campus plaza has glass bottom ponds that look over the expansive underground parking garage.
  • The Ranch grows all of its own food that it serves in the employee cafeterias.
  • The Ranch has its own vineyards that doesn't serve its wine in its employee cafeterias.
  • You can order fresh taun taun from the cafeteria when it is in season.
  • The library is one of the most beautiful private libraries I have ever seen.
  • A colony of ewoks live in the trees just over the hills.
  • The cafeteria serves blue milk in tupperware containers, just like they used to to at Mos Eisley!
  • They have canoes and boats to use for summer parties on the lakes at the ranch.
  • George's office at the main house is off limits to minor employees.
  • George has his own private elevator so he doesn't have to see his employees.
  • George's private elevator goes down to his own screening theater, which has a killer sound system.
  • George is rumored to have a certain Gungan encased in carbonite in this theater.  He uses it as a coffee table.
  • George has the largest collection of original Norman Rockwell paintings on display at the Ranch.  He uses the rest for placemats at his dinner table.
  • The Stag Theater, named after a diner in George's home town, at Skywalker Sound has the best sound system in the entire world, probably because of the abundance of THX technicians that roam free-range on the ranch.
  • Each seat in the Stag Theater has its own subwoofer.
  • There is a rancor pit located in the atrium off of the main house... either that or a wine cellar.  I couldn't really tell.
  • The main house of the ranch contains and displays ancient relics that were supposedly discovered by Indiana Jones: the Holy Grail, the fake Holy Grail, the Shankara Stones, and the Crystal Skull.
  • The Ark of the Covenant was, unfortunately, still locked up at Area 51.
  • All of the main characters' lightsabers were on display as well, along with a model of an AT-AT.
  • A vast majority of the staff is contractually obliged to have facial hair, including the women.
  • Fanboys are tazed if they get overstimulated by all of the nostalgia.  Don't ask how I found this out.

All in all, it was a fun visit and fulfills a lifelong dream of mine.  Next up is the lifelong dream of actually visiting the ranch each day and getting paid to do so.

10/26/11

Thesis Project: Alex Shaders & Hair

This week it was my duty to refine the textures, shaders, and hair of the Alex model for my thesis.  There were a lot of technical challenges associated with this week's work.  One of the biggest challenges was associated with the lighting of the hair.  Typically, there are two ways to do shadows for lights: raytraced shadows and depth map shadows.  With raytracing, your image is calculated by casting "rays" from the camera into the scene to figure out how the lighting and shadows will interact.  This can create very realistic shadows, but is very heavy on the processor.  Depth map shadows work by casing rays from your lights, then generating shadows based on where the light is blocked.  It is much easier to produce these, but they can be memory intensive if you want it looking good.


So thus was my dilemma with the Alex model.  As you can imagine, trying to trace the light source back between half a million polygons and an additional fifty thousand hair primitives was causing some serious crashes if I wasn't careful.  Because I'm still using Maya 2010 for the Mac, I am stuck with a 32-bit program that can't make use of all the extra RAM my machine packs.  It's a shame.  However, I have heard terrible compatability stories with the newer versions of the Mac OS and Maya's programs.  It's sort of a Catch 22 at the moment.


The shaders still feel a bit artificial to me, but that's probably because I'm using regular Maya lights instead of physically accurate lights or an environment sphere.  With image-based lighting, the models would look a lot more accurate than what I currently have.  I plan on doing image-based lighting with the Robot, because I know he will look a whole lot better than with just plain shaders.


Truth be told, I'm ready to be done with this model.  This is the last push!

10/24/11

Advanced Texturing and Lighting: Render Layers

This week we were working on rendering out turntables for our textured models.  Typically, this is where I fail to excel.  When rendering in a studio environment, this is where things get very complicated.  When you render, you do it in various passes.  That means that you render one diffuse color pass, one specular color pass, one shadow pass, one reflection pass, etc.  Once you have separated all of the elements in your render, you can then adjust how they look after the fact, rather than having to re-render your entire scene

video

However, things can get even more complicated when you start breaking up components in your scene.  Take the above video of Chimi, for example.  When I rendered her out, I had the above described passes, but also managed to split it up between objects in the scene.  Her hair has its own set of passes, her clothes have its own set of passes, her skin has its own set of passes, and her eye have their  own set of passes.  You layer these passes on top of one another in a compositing program like Adobe After Effects or Nuke, allowing you to adjust color, brightness, and shadows all after you have rendered.

video

With Ugly Ray, here, things are a bit different since he has particle-based hair using Shave and a Haircut. I had to render a separate hair pass and extract its alpha channel in order to isolate the hair.  It was a bit backwards, but it worked in the end.  All in all, it's not my favorite type of work, but it is necessary to understand how it all goes together in the end.

10/19/11

Thesis Project: Alex – Shaders

This week was a big shift in duties for my project.  I moved away from modeling and onto shaders, which is where my brain starts to get a little bored, honestly.  However, I like putting shaders on my models because that's where they really start to come to life.

First things first, however, I had to pose the model in ZBrush, which I had never done before.  They have provided a little plugin called Transpose Master that allows you to build a rough rig in ZSpheres and move them around to pose your model.  It leaves a few things to be desired, but it sure is an easy way to get your model posed.

Next, I also exported the color maps and normal maps from ZBrush, some of which were the start of my other maps for the shaders.  I also exported about a subdivision level 3 version of the model for rendering, so that I didn't have to play with displacement at all.  Roughly, the model has about 540,000 polygons on it, which is par with what you'd see for hero characters in the industry.


Last night was the first time I got to see everything all put together.  Pardon the terrible haircut.  I am using Shave and a Haircut, a Maya plugin, to do the hair and there are some things that I still need to figure out with it.  However, it's on it's way.

One other thing I tried that seems to be working out okay is using an image map to control the specular highlights on a single mesh.  In times past, you needed to separate the mesh into different pieces in order to apply different specular attributes to it.  However, I discovered that you can use a grayscale image to control numerical values inside of a shader, which is how I am controlling the roughness and highlight size of 3 different "materials" on the same mesh.


Initially, there are some issues I noticed:

  • The overpaint on the pants and boots needs to be increased in order to hide the UV seams.
  • The skin seems to not be showing the bump map that is applied to it.
  • The head seems a bit too red, most likely due to a low diffuse weight and too high of a subdermal weight on the subsurface scattering shader.

Those issues will be dealt with along with working on the hair.  Right now I have learned a lot, but have a lot more to learn!

10/12/11

Advanced Texturing & Lighting: Ugly Ray's Hair

This week's assignment was to start with doing hair.  Now, our normal assignment was to use Maya Paint Effects to generate hair, but I wanted an excuse to play with another software tool I acquired, Shave and a Haircut.  It's a fairly advanced hair system that's fairly easy to use, and I am planning on using it for my project.  There's a lot I have to learn...

I wanted to compliment Ugly Ray with some crazy hair, and in fact did three separate hair objects with different properties each: head hair, eyebrows, and stubble.




I'm running into trouble with some shadow settings and other alpha settings that seem to be cropping up, but hopefully I can fix that this next week.

video

10/11/11

Thesis Project: Alex Surfacing Progress

This week I started to work more heavily on the tiny details of the Alex model.  I went a little sculpting crazy on the clothing and a few of the parts got a little convoluted.  So I did a little back tracking and smoothed out some of the more extreme folds, making the areas much more subtle.

ZBrush seems to handle high-resolution modeling much better than my current copy of Mudbox, most likely because it's a 64-bit program.  I have enjoyed using it for detailing skin textures and other surface patterns.  This week I started the fine detailing of the model, which involved putting a lot more subdivisions into each mesh.  I think the total point count for the model lies somewhere around 17 million points.  I won't be importing that directly into Maya, but rather one that is closer to something like a million.  The higher resolution details makes it much easier to get details out for the normal map when I start rendering in Maya.


I also started using ZBrush's Polypaint tools to create the basic color maps for the character.  I will need to do some additional work in Photoshop to get it looking right, but for the most part, it is looking a lot like the concept artwork.  Well, actually, it's looking better than that.


ZBrush also has done some impressive additions to their lighting system, which allows for HDRI creation.  Unfortunately, I haven't gotten the hang of it just down, so the gamma of each of these images is a bit off.  I tried tweaking it in Photoshop, but didn't get the exact results I wanted.

10/5/11

Advanced Texturing and Lighting: Ugly Ray

 This ugly little fellow is Ugly Ray, another model that was provided for us.  Our assignment with this was to test out the subsurface scattering skin shaders, which I am glad to get more exposure to.  The advances in rendering software had made a huge difference in getting the skin of animated characters to feel more lifelike.  Before, the algorithms that were used just made skin look like plastic.


For this, I thought I'd try one of ZBrush's little known features called Pixolpaint.  With this technique, you are actually coloring vertexes on the model, rather than pixels.  You can then transfer that information into an actual color map for use in Maya or some other renderer.  ZBrush is becoming more attractive to me all the time.


One of the nice advantages of subsurface scattering shaders is the nice, realistic, light leak you get coming from this surfaces like the ear here.




video

We also had to do a "fake skin" shader that used a combination of older shaders to try and get the same effect as a subsurface scattering shader.  However, it left much to be desired:




Diaspar: Alex ZBrush Progress

This week I took another look at the folds on the clothing after getting some honest feedback from my instructors at school.  It wasn't looking like I wanted it to, so I took an additional look at how cloth seems to fall around the knees and shoulders.  It probably still needs work, but at least I'm getting closer.



On a side note, I've been discovering tools and other things hidden deep within ZBrush that I never knew about before.  There are some exciting possibilities for texturing and painting that lie ahead.  I'm discovering some insane difficulties with doing displacement in Maya with some of the clothing, so I might wind up using a higher resolution model with normal maps to get the same overall effect.

Advanced Lighting and Texturing: Chimi Lighting - CSI Style

Although I have been using a 3-point light setup with Chimi this entire time, this week we were supposed to set one up in "CSI Style."  In terms of cinematic 3-lighting, most of the time, the basic lighting will be set up with three lights:
  1. Key light: Meant to be your main light
  2. Fill (or bounce) light: Meant to round out the form and keep it from falling too much into shadow.  Usually about 2/3rds the brightness of your key light
  3. Rim light: Meant to pop your hero characters off of the background.

In the show CSI, apparently, all of the hero characters have a very strong rim light on them, almost to an absurd degree, even though there is no possible physical light source in any particular scene that would do that.


I didn't push the rim light too much with Chimi, but, then again, I don't think she'll be appearing in any CSI episodes any time soon.