Making Bobo Robot vs. Ninja Wang

Special FX filmmaking

The purpose of making “Bobo Robot vs. Ninja Wang” is to take a stab at creating movie visual effects.  It’s always been my personal goal to be able to tell any story I can imagine, whether it includes tornados, monsters or in this case, killer terminator robots with dual action SMG rifles for arms.  You really don't need that much experience to create your own FX films.  This film was created with a novice level of knowledge in Softimage XSI (3 months experience at the time of making this film) and Adobe After Effects (3 weeks – a very intuitive application).  What you do need however is lots of time, patience and more time.  This film was made in about 10 days of continuous labor:
 

- 1 day - planning shooting the film (actually took about 2 hours to shoot in a forest with freshly fallen snow) - 3 days - modeling and rigging Bobo Robot - 6 days - rendering, compositing, animating

In this basic tutorial I will cover the three basic processes of creating your own FX film:

Modeling

Rotoscoping

Compositing

I'll explain each of these in detail later, but before you start that, the first step is planning and shooting your film.  When combining CG elements with live action footage, the first thing you will need to do is storyboard your shots.  Visualize the whole film in your mind and draw it out, shot by shot.  Storyboards don't have to be complicated nor master works of art.  They just need to be enough to remind you of each shot so when you are out in the hectic-ness of your location you will have a nice to-do list of shots in your hands.  Below is a page of my storyboards, quickly drawn and taken on location where it got stepped on, crinkled up and blown around.  And that's fine because the storyboard is your friend.  The yellow check marks are completed composite shots...

The Design

Designing your 3D models can be one of the most tedious tasks.  Mainly because its in this stage that you need to fully grasp your 3D models from every angle possible.  Its important that you don't skimp on this stage because when it comes time to model, if you are unsure of what you want to make, you end up wasting many hours fiddling around with even the smallest inconsequential details. 


I like to draw my 3D models in different angles, roughing out the shape and main details.  It may take many tries to come up with something that you are happy with.  And visualizing in 3D is not always an easy task.  But take it one step at a time, design the main body, then individual parts and bring them together.  When I am happy with what I've designed, I move on to the next phase.

Once you have a clear sense of your lovely 3D character/model, the next step is getting into your 3D application and start modeling.  Modeling takes many hours and there is no quick method to making a quality, highly detailed model.  Bobo Robot took about 3 days of continuous modeling, about 25+ hours or so to make.

For symmetrical models, the recommended method is to model only one half of the model and clone the other half.  That way everything you do to one side will be reflected in the other.  This saves tons of time of course and since this was only a test project, I found it convenient to have Bobo to be completely symmetrical.

The basic shape of Bobo was pretty easy to come by.  His head (body) is a simple primitive sphere with a stretched deformation near the "chin."  I drew the individual lines of the metal plates and then extruded them to give them depth. 

I went on to make the arms next.  For the arms, I drew 2D polygon shapes and extruded them out, added bevels and just sat there for hours making little indentations and other details.  The same deal for the legs.

Overall, you will find yourself spending lots of time detailing things, and its just the reality of 3D modeling.  So if you are making your own 3D models and wondering why its taking so long and maybe there is something wrong with you, well don't worry, nothing is wrong with you - its just a tedious process.

After you are finished with the modeling, texturing comes next.  Again, with limited time, I decided just to give Mr. B a nice shiny material and leave it at that. 

Your model is complete, what next?  It's time to rig it for animation.  Rigging basically means giving your model a skeleton.  The skeleton is attached to your model and is then moved around in 3D space to be animated.  Rigging Bobo was a simple task, as he only need to move his arms and legs.  In the pictures on the left the green sticks are the rigs for the legs...
 

KEYING
Keying is the process of taking live action footage and isolating the area you want.  Usually this involves shooting the actor in front of a blue screen.  For this film, I had no such time of acquiring a blue screen or going to some blue screen stage to shoot the ninja in action.  A quick work around was to frame myself behind a white area in the background (see pic below).  Since I was wearing dark clothes, I figured it might work.

Unfortunately while performing my ninja actions, I shifted my body too much and a lot of trees and dirt and various things got into the background making keying a nightmare.  Isolating the white areas was easy, but I had a lot of garbage areas in my footage.  I didn't have time to mask out individual frames (which is basically drawing a precise outline of the subject in each frame - taking huge amounts of time), so I ended up creating a garbage matte around myself, isolating out most of the background and keying two colors - white and grey.  The grey started making holes in my body...but it was forgivable.  In the really really bad frames when there was an entire tree blending in with my arm for instance, I added five different blurs inside After Effects to compensate.  Even so, there were still many blotchy areas in my images (as you can see in the image below) but because I had a busy background and the ninja hologram illusions were semi-transparent, the garbage around me is hardly noticeable (composited image  below)

YES if you have a blue screen use it.  Just make sure that the lighting matches if you are shooting indoors.  If you can, bring your blue screen with you to your location.  It might look kinda funny, carrying this big blue wall around, but if you are handy, you can get a large blue cloth you find at craft stores and build a collapsible stand with some parts at a hardware store.  Trust me it will save you hours of time.

ROTOSCOPING
Rotoscoping in this case is the process of combining CG elements with a live action background plate.  I first captured a few screen grabs of the background that I wanted to combine the CG with and brought that image into Softimage.  I set the background plate as the rot scope so it shows up in the workspace and just played around with the lightning until my rendered CG model of Bobo looked like it matched the lightning in the background.  I also made Bobo's surface shiny and reflective, so to give an illusion that Bobo was really reflecting the environment around him, I used an environment shader inside XSI which basically takes an image and wraps it around the model.  Ideally, you need to use an image that has a spherical projection so that when it is wrapped in a spherical manner, a true 3D environment is emulated.  Again, since time was not on my side, I just wrapped one single picture of the environment that I took with my digital camera into a sphere and used that for my environment.  Although highly inaccurate, it got the job done.  Just as an extra bit of interest, if you want to get really good real world lighting, there is something called an HDR image, standing for High Dynamic Range.  It is an image that compresses several exposures of the same image into one.  It also is an image taken of a chrome sphere so that a full spherical projection is wrapped up into the image.  For added realism HDR's are the way to go.  With no time on my hands however...



Much time was spent working in XSI and timing the animated actions of the Bobo robot.  The rig (skeleton) of Bobo was individually keyed for each movement.  Again, because of time, I completed a very basic rig that made Bobo's limbs move...much of the movement was rough and stiff, but it was ok since this was only for practice.  Overall, there was over 1,500 frames rendered for all of Bobo's movement in this short little 1 minute film. 

THE NINJA STARS
The ninja stars or shurikens was probably the easiest thing to do in this film.  Time was running out so I modeled a simple ninja star thing and made it shiny, and animated its rotation.  For the shots when Wang the Ninja was chucking the stars, I animated the spinning stars along a straight path and added a motion blur.  I rendered out several different angles of the same animation to give the ninja star throwing sequence extra variety.  Compositing for the stars is the same process as compositing Bobo.  As I worked, I drew what's called inside XSI a render region around my object (see yellow box in pic below) that renders out the object with all its reflections and tweaked the light sources in my 3D scene.  I played around until the star looked like it naturally belonged inside the scene and then rendered out final animations.  Not too hard eh?

Together at last!  You have all your elements: keyed live action footage, background plate, and CG animations.  Compositing is the process to bring all these together into one final seamless (hopefully) shot.  In the series of pictures above, I had four elements: the keyed ninja, the 3D robot, the background plate and the CG snow.

Everything except the background plate has something called an ALPHA channel, which is basically a transparent color for which other layers can show through.  Notice the black areas in the CG snow or robot...that black color is made transparent so the background plate can show through.  Inside After Effects, importing elements such as pictures with an ALPHA channel will be automatically treated so that the transparent areas will become just that: transparent.

Within Softimage XSI, I rendered out a series of TIFF images with an ALPHA channel and imported into After Effects as a TIFF sequence.  I then layered all the elements on top of each other, tweaked them until they looked like they matched each other and rendered out a final shot.

For the shots when we see the robot vision and the scanning, I drew some hi-tech looking cross hairs using Flash, imported them into After Effects, made them move around and blink.  I used a spherical distortion to give it the fish-eye look and added a strong red tint to everything.  With some random details here and there such as some hi-tech sounding text, I had my robot vision completed.

Editing and Color Correcting

So now you have all your FX shots completed.  The final (and most fun) step is to put all these clips together, add sound and watch your creation come to life!  Editing your film digitally is basically arranging your clips in a linear sequential order on a "time line." 

Editing this film took about two hours of arranging clips and making the sequence right.  The most important aspect of editing this film was to find the tempo and rhythm of the action.  Tempo and rhythm are extremely important when executing action films, because when there is a lot of action happening in your film, your audience will see one of two possibilities: a chaotic mess of nonsense (leaving them bored) or a graceful action piece that leaves them breathless.  There is a fine line that is drawn between these two extremes and even if its your intention to make something chaotic, your execution will make the difference between making an impact or boring them to death.
 

Find a rhythm that works.  Tap it out on your desk with your fingers.  Jackie Chan's actions films are choreographed with a very carefully selected tempo...if you converted his moves into a song, you would most likely end up with a dance beat!  The most important thing however, is just to make sure that your film makes sense.  The continuity of a film is very important.  If you have poor continuity, there goes your audience.  Hence, again I stress the importance of planning and storyboarding.

Color Correcting.  Many digital editing applications have color correcting tools that allow you to mess around with the colors of your image.  I wanted to give my film a cold blue look (its snowing after all).  In advanced color correcting tools, there are 3 ranges of colors that you can modify: lows (shadows, dark areas), mids and highs (highlights).  I simply dragged the mids down towards the blue to give my image a bluish tint.  I then increased the contrast of each shot to give it more range and an increased saturation.

BEFORE color correcting

AFTER color correcting

Sound
Once you have your colors and your edit done, the last step is to add sound.  To be honest, sometimes I just cant wait and start sound as soon as I start editing.  That's cool, whatever works for you, but make sure you don't get carried away and spend too much time on the sound design and neglect the editing!

There are tons of free sound effects resources on the net.  My top two sites I go to for sounds is:
http://www.findsounds.net
http://www.flashkit.com

When you download your sounds, its just a matter of timing them to coincide with the action of your video.  If your editor can layer audio, you can have multiple tracks of sounds, for example, making a punch impact sound more dramatic by placing two different bone crunching sounds on top of each other.

Well that's it, a basic overview of making an FX film.  Drop me a line if you have a specific question.  Until next time...

young@younghlee.com
http://www.younghlee.com