Graphics Industry Fun

Hollywood and video games

2008-07-11T10:24:00.000-07:00

As much as Hollywood enthusiasm and willingness to work in creating an engaging video game title helps, it can also get in the way. All the resources working on an interactive project should have a basic knowledge of the game development process which is so different from film making. Knowledge of timing constraints associated with development can help to ensure that meetings are scheduled and approvals are received when needed. It can be frustrating to reach alphas and betas only to receive a list of proposed changes from an approval request originally sent two months ago.

Its also helpful if the talent understands not only basic game play but also the potential limits when it comes to game design. If an award winning writer does not understand the basic content required for a game story line and dialogue, he might end up writing an amazing script that features little that relates to the title's gameplay or the addition of new and exciting game characters with fantastical physical technology that exceeds the limit of the game engine. The issues that arise from working with some of the most creative minds in entertainment can be resolved but it takes time and unfortunately time is a developer's most valuable commodity.

So this influx of talent from the entertainment industry is inevitable and the addition of some of the most creative writers, directors, animators and artists can do nothing but help the game industry move forward in its quest to create memorable interactive experiences.
From a developers point of view, when working on licensed IP, I've learnt the following lessons.
Take the time to meet with creators at the beginning of the development process to present the team, procedure, project management processes and goals. Most people are willing to resolve the issues that arise when merging one medium into another because noone really wants a bad game, much less a bad game that does not sell well.

Video game industry

2008-07-10T09:00:00.000-07:00

The Video game industry is currently the darling of the entertainment industry. Just pick up any Hollywood trade magazine and there will be an abundance of stories testifying that interactive entertainment is the place to be. Everyone from directors, writers to actors want to at least have a toe in the business and where they want to go their agents will lead them.

This sounds fantastic. But with access to all this talent, how do you think it could fail? Well... there are plenty of potential difficulties yet there are certain advantages that result from the influx of talent and access to Hollywood resources that the gaming industry is making games like King Kong and James Bond.

Simply put, the focus and attention being given to games based on movies is good for the video game business. Publishers and development teams are being allowed unprecedented access to talent and are allowed to run with the ball and create standalone experiences that extend the original IP and the result is better entertainment for the masses. There are usually a lot of brainstorming meetings scheduled during the beginning of game development. Writers, artists, directors, and animators sit down with produces, designers and programmers to share ideas and agree on the general direction of the game and everyone is given much more freedom.

I have been in many such meetings. From the Tech lead programmer perspective, I give rough estimates and resource promises to meet their budget requirements. The room is filled with creative talent. The collaboration will likely get to the point where the game designer or the film director will become so excited by the creative opportunities that they will seem to speak in a secret language.

More later.... hold on tight.

Cloth animation

2008-07-09T08:36:00.000-07:00

Cloth animation
One of the biggest challenges in computer animation has been to simulate how clothing bunches up and then relaxes again, as when a character's elbow bends or arm moves across the front of the body. The problem with conventional cloth simulation techniques is that during such motions, fabric becomes sandwiched in areas where it intersects with the body and itself and it gets pulled stretched and tangled. As a result, it can flutter, wiggle and appear jagged. And then, when the body parts separate, it can remain pinched and tangled instead of falling loosely and naturally back to its original shape.

To avoid these problems, David Baraff, Andrew witkin and michael kass of Pixar (owned by Disney), have devised two cloth simulation and collision algorithms described in Siggraph in a paper called "Untangling cloth". The first is called collision flypapering, which eliminates nearly all visible artifacts in regions of body intersection by carefully controlling the motion of any trapped or pinched cloth points. The accompanying figure shows how the fly-papering algorithm produces realistic cloth simulations when clothing would otherwise get pinched from typical body motions of a CG charater.

The researches also have developed a cloth-to-cloth collision algorithm that peforms a global intersection analysis of the intersecting cloth meshes. It instantaneously charaterizes the current intersection state of the fabric in order to guide the cloth back to an untangled state where the intersections occur.

Job Nature in CG

2008-07-06T15:52:00.000-07:00

Animation Director:
This position is responsible for supervising a team of animators and for developing the behavior of all the digital characters in a production project. For larger, character based feature films like Casper, Star wars I, the most senior Animation directors might be placed at the same level as the Visual Effects Supervisor. In this case, he/she might report as much to the Director as to the Visual effects supervisor.

Compositor:
A compositor combines many different rendered and scanned raster elements into a finished image or show. These elements often include a background image or live-action plate, rendered CGI elements, rotoscope mattes, and other digital matte paintings. The compositor must integrate all these together by balancing color and black levels, and by adding subtle amount of nuances such as flash and grain. The ultimate goal is to make the composited elements appear to have been captures as a whole. After all, its all 2D in the end. Excelling at this job requires a thorough understanding of color, light and film.

Computer graphics sequence supervisor:
This position has thorough knowledge of the tools in use on the production, excellent organizational skills and a great aesthetic sense. He/she works between the Technical director (responsible for individual shots) and the CG supervisor.

Technical director:
Mu favorite position in the entire graphics industry. Responsible for the direction of the technical aspects of an effect shot, although the term might mean different things in different companies. The job is to assemble the many different elements from Modelers, animators, painters, matchmovers, rotoartists, to create a finished shot to the Director's satisfaction. Sometimes, this job also requires to do compositing and effects animating.

Jobs in Computer graphics field

2008-07-05T06:58:00.000-07:00

Software Developer:
Being a software engineer myself, I can't resist listing this first. A software developer is one that develops software...duh... who writes code and custom tools that the production team uses. Programmers should work with CG supervisors to determine just how far off-the-shelf software can take the project and what needs to be written from scratch in-house. During development, the software developer works with the Technical Directors who use the early versions of the software and help the designer refine the tools to include the best features and interface. Although most often not considered "in production", a software developer is very much part of the team effort that gets a show done in time. A software developer might report to a CG supervisor on a large show or to management as part of a facility's more general overall scope of operation.

This job requires knowledge on programming languages like C, C++ or Java and scripting languages like javascript, perl, python working on operating systems like UNIX, Max or Windows. R&D team members generally have a PH.D. degree in Computer science specializing in one of modeling, rendering or animation areas.

Computer graphics Vs. Traditional methods

2008-07-03T06:15:00.000-07:00

As with any artistic endeavor, the final result is only as good as the skills of the people creating it; the tools are always secondary to the talent. Practical models have a distinct advantage in their interaction with light on a set or outdoor environment. Our eyes are accustomed to viewing images captured in a real space through a lens and onto film. The many subtle nuances of this seemingly simple and commonplace technique are very time consuming and are difficult to duplicate in an all-digital environment.

Creating a completely realistic all-digital reality occasionally is done so well that it goes unnoticed altogether. Most times, the whole point of a visual effect is to blend seemlessly into the context of a film and not stand out at all. Mission impossible is a movie that is an excellent example which had several such sequences. One of the scenes depicted a helicopter entering a tunnel entrance. No sets or models were used at all, but you never know it.

One of the biggest advantages of computer graphics is being able to do a job when it cannot be done any other way. In the movie, Small soldiers, ILM created more than 300 shots with many hundreds of interacting commandos and Gorgonite action figures, all completely digital and integrated perfectly with the live action sets. Achieving that volume of photorealistic animation on a very strict production timetable would not have been possible with any practical techniques. The animators even had to match with the few live action puppet closeup shots.

Visual effects

2008-07-02T05:32:00.000-07:00

Computer graphics is extensively used to create visual effects in Hollywood movies and video games. Pixar, Dreamworks, ILM, Digital domain are some well known companies in this area. Traditional models and miniatures are still very much a part of the visual effects used today. In many ways, more miniature work is being done lately because of the resurgence of big effects pictures. This was brought on by the advances of the newer digital technologies.

The largest single difference between any traditional effect and CG is based on the nature of the medium. Models naturally have physical limitations, both in how they are constructed and how they are captured on video. It is important to note that most CG models are created from some traditional reference sculpture made out of clay. The clay model is scanned by a microscribe digitizer that generates millions of 3D points depending on the sampling density used. There are sophisticated software available to convert the 3D points into a digital model. The process of constructing a digital model from a cloud of points is called surface reconstruction. They can either fit a polygonal mesh over the point cloud or a NURBS surface model. Geomagic, Paraform (now out of business) are very expensive $20K software that specializes in surface reconstruction tools. CG is limited only by the designer's imagination.

A combination of both should be used to take full advantage of both techniques. For example, I know ILM used the combination technique in transforming the black sedan sequence in the movie Men in Black. The metallic quality of the car itself and the very intricately animated surface structure and jet exhaust are all well done in CG. The tunnel through which the car travels is a miniature set that needed to be realized with thousands of cars.

Rendering in computer graphics

2008-07-01T17:17:00.000-07:00

Rendering phase is where geometric models, light effects and mathematically defined animation paths are turned into realities. Trust me it is extremely difficult to create computer graphics images that look realistic.

I am going to list the major milestones in computer graphics rendering below.
1. Wireframe rendering: The simple vector graphics represention of polylines or any surface geometry.
2. Hidden line rendering: Shows only portions of the surface that face you directly.
3. Surface Shading: Flat shading of one color per polygon. No interpolation at all.
4. Gouraud Rendering: Interpolates each pixel value from each vertex illumination value.
5. Phong shading: Uses the surface normal information when interpolating the vertext values.
6. Ray tracing: Advanced lighting techniques and reflection, refraction and specular, diffuse, emission, ambient kinda values are taken into consideration.
7. Radiosity: A good compliment to ray tracing technique. It calculates lighting based on global illumination techniques as well.

Bump mapping, displacement mapping and texture mapping add rendering details to existing geomety. It is the technique of creating surface detail through surface normal perturbation. The shader function is defined by 8-bit data. It only perturbs surface normals and does not directly affect underlying geometry. Displacement mapping does afffect the underlying geometry.

Autodesk's product Maya has excellent rendering tools. They have thousands of different shaders that can be defined using various parameters.

Animation in Computer graphics

2008-07-01T05:34:00.000-07:00

Animation is giving life to digital models. It means changing something over time whether a model's position or just a color value in a rendering style. There are two techniques usually employed in computer graphics.
1. Procedural animation
2. Keyframe animation

Procedural animation is generating motion through mathematical or rules based languages. Twister, Star wars, Armageddon are some movies that used complex rules to degine the movement of particles in animation. These rules can be based on accurate physical principles or they can be faked to skew towards a particular desired effect. After these rules are started, simulation runs its course creating its own effects designed by the artists. This technique sometimes results in different outcome than what was expected. This requires changing the rules and running the simulation again. This is time consuming, but executed properly, procedural animation can bring some complex animation to life which cannot be achieved by any other means.

In traditional keyframe animation, specific values are set for a given attribute that has to moved and the computer generates interpolating curves that join successive keyframes. At any point along the curve between these keys, the computer evaluates the curve to resolve to a value. Most often, the whole number frames are used to generate the beauty pass of the image. The intermediate frames are used to create the motion blur.

These two methods fundamentally differ from other animation techniques such as stop-motion or cel animation which requires the animators to draw every single successive frame one at a time from start to end.

That is my ramblings for today. More later...

More modeling techniques

2008-06-30T10:12:00.000-07:00

The basic concept of subdivision surfaces is not new as it is originally published in a paper written by current Pixar's CEO Ed Catmull in 1974. However the technology did not get popular until it was used by Pixar in modeling Geri's head in a movie. They had realistically designed the creases both hard and soft in Geri's head, noses and knuckles and clothes.

New technologies arise from university labs. One such example is the photogrammatery software that creates 3D geometry from analyzing multiple 2D Photographs by interpolating corresponding points between these photos.

It is all about the design data and its applications. If it is only to visualize (say in video games or movies) and not for manufacturing, there is no need for a lot of geometry. With little geometry and detailed textures and sophisticated bump and displacement maps shaders can represent a wide variety of models.

Unlike geometry based on some primitive shapes or NURBS or just plain old polygonal meshes, mathematically described implicit surfaces also known as isosurfaces are the basis for functional modeling. Surface is defined using the superposition of Gaussian potentials representing individual atoms. Many design software like 3DS Max and Maya have a feature called metaballs thas implements this technique.

Constructive Solid Geometry is the technique widely used by MCAD software and B-Rep (boundary representation) is used by CATIA, Autodesk Inventor, etc. In CSG, complex objects are represented as boolean operations on simple primitive solids like cone, sphere, tori and blocks. Some CAD/CAM applications use this technique.

In B-REP, objects are defined using topology and geometry. Topology represents the connectivity between various entities like SHELLS, FACES and EDGES. Geometry actually defines the data underneath the FACE or EDGE.

I will talk about animation in computer graphics tomorrow.

Computer Graphics Fundamentals

2008-06-29T17:40:00.000-07:00

Computer graphics has three main areas of concentration.
1. Modeling
2. Animation
3. Rendering

Subdivision surfaces are the latest in the geometric modeling area. There are some unknowns in this area and is an active research area in the graphics community. There are many open problems for PhD ideas available in this area. We need breakthrough results in this area to have it being used in commercial products for manufacturing. Not having C1 is a major letdown. Also, booleans operations and other solid modeling operations on a subdivision surface are still a major challenge. Currently these are used in products aimed at video games and movies. These models will visually look pleasing and smooth but are not mathematically smooth. Manufacturing these surfaces will be an issue.

Inverse kinematics is an active research area in animation. Maya is the world leader in providing animation modules. Cloth animation and fur animation, particle simulation, crowd effects are recent additions.

Photorealistic rendering and fast and accurate global illumination for lighting effects is very active in the area of rendering. Many university labs are doing active research in improving rendering techniques. Cornell university comes to mind immediately.

More on further research studies in a future post.

Geometric modeling - mathematical representations

2008-06-27T18:59:00.000-07:00

There are many ways to define the geometry of a digital model. Some popular ones are
1. Polygonal meshes
2. NURBS (Non-Uniform Rational B-Spline)
3. Subdivision surfaces
4. Implicit surfaces

There are software packages entirely based on one of the above to internally represent their models. Rhino, AliasStudio are pure NURBS based modeler. Some software like 3DSTudio and Maya have both meshes and NURBS representations.

Meshes vs NURBS have their own advanatages and disadvantages. For example, to represent a perfect sphere as a mesh object, we need thousands of tiny triangles to get the smooth curved shape of a sphere. NURBS can represent a sphere with just 9 control points and a few knot values. However, NURBS need to have rectangular surfaces (as they are parameterised in 2D space). Trimmed NURBS are common to represent freeform surfaces but they have leak and gap problems between surfaces.

Subdivision surface came as the rescue to solve both these issues. We can represent arbitrary free form surfaces with less control points. However, mathematically some regions of the subdivision surface is not smooth (not C1 continuous).

There are pure subdivision surface based modelers out there. Modo, Silo are some examples. They have huge limitations in the kinda models they can represent. They work great for certain applications.

IT is a great opportunity

Data Translation

2008-06-24T08:43:00.000-07:00

CAD data can survive many changes and iterations and still retain its integrity only if the chain of data remains unbroken and all departments have access to it in appropriate forms. Miss this point and you open the door to the probability of lost time and resources. Companies have to find reliable distribution and translation methods to reduce loss of data quality.
Before exploring the various distribution methods, companies have to determine exactly who needs design data in various departments. The answer may be obvious but careful examination might bring some surprises. The purchasing department may send out hard copy drawings for quotes or even for tooling. If so, the data will most likely be redrawn or recreated on a CNC machine somewhere with all the possiblities for simple human error. The sales department may be sending drawings to customers - make sure they are sending the correct versions and are tracking what they send. The minute a CAD model leaves drafting it may no longer agree with the design data so there is some definite potential for noncompliance with the released design unless they are properly controlled.
IGES (Initial Graphics Exchange Standard) is a graphics file format for 3-dimensional models. IGES files contain surfaces, so they are a natural choice for distributing the CAD data to anyone who does machining. However, IGES translations can be difficult and frustrating due to a variety of differences in the CAD products and the vagueness of definitions of the file format. Properly done, though, IGES translations do contain accurate model data and are compatible with most machining packages. Newer CMM and other digital inspection hardware are able to compare model data with acquired data points to generate reports and 3D color plots that visually display feature compliance.
STEP (Standard for the Exchange of Product Model Data) files, which contain non-parametric solid model data are smaller than IGES files and are usually easier to translate. Companies doing original designs for their customers can transmit design data back and forth in STEP format while retaining the engineering properties of the objects.
STL (Stereolithography) format is commonly used in rapid prototyping business.

Geometric Modeling

2008-06-23T17:01:00.000-07:00

The core strength of all the CAD products is their design capability. All these products started out as B-REP (boundary representation) modelers. As they evolved, they developed more modules to better serve the need of customers. They developed modules for simulation and analysis, finite element analysis, computational fluid dynamics, tubing and piping, cable and harness, electric circuit design, and data management solutions.

Companies that deviated too much into other categories and lost focus on their core modeling are in big trouble. PRO-E can be cited as an example.

Usually customers use a surface modeling program like AliasStudio for conceptual design. Then they use a solid modeling program like CATIA for mechanical and manufacturing design. There are some programs out there that can do hybrid modeling ie. surface and solid modeling. CATIA has a surface modeling module. Their recent release of expensive Imagine and Shape module sounds very promising.

They have combined mesh modeling into the manufacturing design process that is pretty innovative in my opinion. I can talk hours and hours of NURBS based modelers and subdivision surface modelers. Imagine and Shape is the first product out there that combines the best of both worlds.

I have to admit I did not have a chance to try the program myself to write any review. But the idea sounds very interesting and as it evolves more, I see other companies do the same after this technology gets proven.

Interoperability between CAD products

2008-06-21T00:06:00.000-07:00

A long standing problem in the CAD industry is the interoperability issue between CAD products. Usually users cannot do everything in just one product. They start the conceptual design in one product (say, in AliasStudio), take the data to a solid modeler like Autodesk Inventor, finish up the engineering design, take it to CATIA for more design and some simulation analysis, etc.

When data gets translated between systems, they lose their integrity with every data translation. Many products support industry standard neutral formats such as IGES or STEP, CAD vendors also support direct translators.

For example, PRO-Engineer can read CATIA files directly. However, the native file formats are not open...meaning, the file format is not published. In order to read CATIA files, pro-e has to reverse engineer CATIA's file format.

Autodesk's most popular format is DWG and it is not open. It is one of the most reverse engineered formats. http://www.opendwg.com is a forum just to reverse engineer dwg file format.

CAD Products

2008-06-18T08:51:00.000-07:00

Manufacturing CAD (MCAD for short) is a growing market due to explosive economic growth in the BRIC nations (Brazil, Russia, India, China).

Dessault, Parametric tecch (PTC), Unigraphics (UG) and Autodesk are the market makers in this industry.

Dessault develops CATIA (high end MCAD product)
PTC develops Pro-Engineer
UG develops UG-NX
Autodesk develops Inventor (mid-range MCAD product).

Other mid-range products include Solidworks, SolidEDGE, etc. (smaller companies like Think3, Alibre exist too).

Autodesk Inventor shows tremendous potential to win over Solidworks and SolidEDGE and become the leader in mid-range CAD products. During the course, it looks like to win over high end products like PRO-E and CATIA. Autodesk's billion dollar cash reserve and its powerful marketing muscle may acquire good talent and propel Inventor to new heights.

Given that ADSK at $39 per share looks like a good buy. I personally think it may reach $50 in a year.

modelers

2004-07-28T20:23:00.000-07:00

There are three popular mathematical representations for digital models. Polygons, nurbs and subdivision based algorithms. Many applications support all of them in various levels. Alias maya, softimage have good polygon modeling tools. Alias Maya also has nurbs and subdivision. Rhino is pure nurbs modeler. modo is pure subdivision based modeler.

Reverse engineering continued...

2004-07-11T20:57:00.000-07:00

Reverse engineering has always been a hot research topic in the universities. Stanford university gave birth to a product called Paraform (financially backed by paul allen). In 1999 and 2000 there was a lot of noise about this company. But they burned all the cash(abt $70 million) and had to close the doors.

Geomagic is another product from Raindrop geomagic in north carolina university. These products costs around $20,000 and serve a niche market. They do an amazing job of cleaning up point cloud data and forming surfaces fitting those points.

reverse engineering

2004-07-08T07:35:00.000-07:00

Reverse engineering is the process of generating a digital model from its physical counterpart. First, the real physical part is scanned (using a digitizer or any kind of scanner) to obtain a usually dense point cloud. There are sophisticated algorithms that take an arbitrary point cloud and convert it into a digital model. There are various representations of a model. It can be a polygonal mesh or a set of nurbs surfaces (stitched together) or some other mathematical representation (subdivision surfaces, implicit reps are also popular).

Geomagic, Paraform, Surfacer, RapidForm are some of the popular reverse engineering products. More abt these companies and their products in my next post...

more news

2004-07-01T08:14:00.000-07:00

Daz3D, a salt lake city, Utah based company has purchased the Bryce division from the troubled Corel. Corel had originally acquired Bryce from Metacreations. Metacreations sold many of their 3D graphics products three years ago to different companies and moved to NewYork to start their online 3D product called viewPoint. Bryce is a good and affordable ($100) 3D product that is good for landscaping or terrain modeling.

graphics modeling products

2004-06-25T18:29:00.000-07:00

maya and 3ds max are the most popular in this category. maya is mostly used in production studios to create visual effects for movies. 3ds is mostly used in game development studios. maya is developed in toronto, canada by Alias. 3ds max is developed in san francisco and montreal by Autodesk.

Maya which was owned by SGI till last month was bought over by some investment firms for 57 million US dollars.

Some other products in this area are lightwave3d, cinema4D, electric image, etc. Rhino is another well known product (pure nurbs based modeler) used by people in a variety of professions.

Next blog will report about some reverse engineering software...

core modeling kernels

2004-06-22T18:35:00.000-07:00

Two major geometric kernels available on the market today :
1. Parasolid - developed and owned by UGS. (Unigraphics - they use it in their products Unigraphics, SolidEdge) and also license to other customers. Development is in UK.
2. ACIS - developed by Spatial, boulder, colorado company owned by Dessault systems.

There are other propreity kernels used by other CAD companies.

Autodesk - has Autodesk ShapeManager used in Inventor, AutoCAD ,etc.
Think3
VX - varimetrix corporation
PTC - Granite

The interesting thing is competitors are heavily dependent on each other for their kernel and other libraries. For example, Solidworks (owned by Dessault) uses its competitor's product, Parasolid. Autodesk owns Mechsoft, a functional modelling software- used by all UGS, Solidworks, etc.

More rambling later...

Introduction to this blog

2004-06-20T12:44:00.000-07:00

Hope to post hot news, comments, thoughts, discussions in graphics, game and the CAD industry. Focus would be on companies that provide software tools to help advance these technologies. Adobe, Alias, Autodesk, Avid, Bentley, Corel, Dessault, Geomagic, Intergraph, Microsoft, NewTek, GraphiSoft, Parametric Technology Corporation, UGS, products like ProE, CATIA, Inventor, Solidworks, SolidEdge, 3DS Max, Maya, Cinema4D, Rhino, Lightwave 3D, Softimage, Electric Image, etc...