[NanoGator]

Greetings all,

I had the opoprtunity to work on a fun little short movie a couple of months ago called Rocket & Co.. My contributions included creation of a digital set, compositing of a 3D robot into live-action footage, and a some digital double work. I thought I'd talk a little bit about some of the work I did on this movie.

First, I'd like to show you all the robot. I'm saddened to say that a lot of the work I did on the robot was trimmed in the final version. However, I thought some of you would like to see some insight into how our friend "Calvin" came into being. I was contacted last year by Christopher Lombardi about designing a robot for his short Rocket & Co.. After a short discussion in email, I went to work designing a few concepts for him to examine.

Here are a few of the concepts I cooked up for him:





In the discussions we had, the most important detail was that this robot had to have character. He referred me to Iron Giant and Metropolis and a few other examples of robots he liked. So I gave him 3 distinct designs for him to mix and match with. After recieving them, he picked the one he liked the most and doodled a little on top of it. Once done, he sent me that doodle and I was off to do one more design.



That was it. He loved it. He wanted me to take that one further. So that's precisely what I did! We had our basic design down. So, I refined it from there. I should mention that this really was a 'spare time' kind of project. I only had a few precious hours in the evening to do this work, so I apologize in advance because the drawings aren't as refined as I've produced before.

I needed to take a 2D doodle and turn it into something more three dimensional. The interesting thing about not having a lot of time to work on projects is that one becomes innovative. I had to figure out a way to refine the three dimensional shape of this robot rather quickly, and simplify the modelling task as simply as possible. I decided to use a technique similar to what I did in order to make my Advanced Ore Refinery. When I designed that station, I actually started with a 3D primitive, rendered it, printed it, and drew the details on top of it. I didn't have the time (or my drawing supplies as I was in-transit to Santa Maria) to go to paper, so instead I relied on Lightwave's curves.



(warning: I work at 1600 by 1200, so the resulting image is pretty large.)

This method was quite advantageous for three reasons. 1.) I could rotate the curves in real time and get a sense of the 3-D shape of this robot. 2.) I could do a screen grab right to Photoshop so I can doodle right on it with my tablet. (if only pencil and paper had a Photoshop style undo...) 3.) Those curves could sit in the background while building the model. When I recieved a thumbs-up from Chris, I built a 3D mockup so I could test the rigging etc. With that mockup built, I did one more (supposedly) final detail drawing.



This drawing has most of the detail that was put into the robot that made it on screen. Though his design did change one more time, most of the elements here made it into the final model. Originally, the robot had a much larger part in the movie. They filmed an actor in a green suit to perform his movements. The CG version of the robot was intended to be overlaid on top of the footage with his motions matched exactly to what the actor originally performed. Because of this, the robot needed to be altered one more time in order to match the actor's proportions as closely as possible. Chris sent me some reference footage to model the robot to. With that imagery, I did one more drawing and one more final mockup of the robot with its final proportions.


(the image on the right was my backdrop while in Modeler...)

And here's a test shot with the mockup:


And with that, I started the modelling. I didn't have long to model this guy. Somehow, though, I cranked it out. (at the cost of a lot of sleep.. hehe.) When I was done modelling, I realized I was a little over-zealous with the detail. I don't recall the polygon count, but when all was said and done it was at least 200,000 polys, possibly as high as 500k. Keep in mind, though, that a.) this was subpatched, and b.) he had fully articulated limbs all the way down to his fingers. Instead of trying to optimize him down, I ultilized an alternative approach. I made a real simple mockup model that responded really quickly in Layout. I wrote a little Lscript that would automatically switch back and forth between this model and the full detail high res version. So the process was like this: 1.) Load model. 2.) Animate Model. 3.) Run Script to flip it into the high-res mode. 4.) Perform test render. 5.) Run script again to refine the animation. It worked beautifully.

Click here for a short clip of the robot rotating... (DivX 5.0 required.)

When it finally came time to animate and render the robot, it was decided to cut his scenes short and focus my energies on working on digital doubles and a CG set for the Rocket & Co. lair. In the end, only two robot shots made it into the final movie. One shot, in particular, proved to be quite challening. It was time Calvin's unveiling. In the original clip, Allistair (the bad guy) pulled a sheet off of the green-suited actor, then passed in front of Calvin as he explained his sinister plans for the city. Unfortunately, during filming, they weren't able to put a greenscreen behind the actor. (Long story...) So I had to manually cut out Allistair and put Calvin behind him. This also meant I had to reconstruct the BG behind him! I had never really gone this far in After Effects before, but I think I pulled it off despite the limited time I had.



Click here for Calvin's 'unveiling' shot... (note: DivX 5.0 required)


Man, every step of this was challenging. This shot was a little over 10 seconds long. Mainly, I used animated masks to cut Allistair out of the shot. Everything is real up until he pulls the sheet off of Calvin. At that point, I cut to the artificial background. Allistair was cut out via animated masks in AE. I also did a little color keying and spill supressing in higher detail areas. (If you watch carefully, you can see hints of that... *sigh* if only I had more time on it...) Fortunately, the sheet wasn't too tough as it only obscures Calvin for a few frames. I used an animated mask with a high feather value to simulate the blur of the sheet as he ripped it off.

I expected that replacing the BG plate would be easy. Err, it wasn't. I had to make *sure* that I used the exact frame that I performed the cut as the BG reference. Since the camera wasn't locked off, this created a lot of trouble. I ended up using AE to make the plate. (I wouldn't normally have expected that, but it just *worked* in this case.) I created a new composition and using masks I created several pieces from different frames of the footage. It took a lot of layers, but AE gave me all the tweakability (i.e. rotating of clipped images) I needed to fine tune this shot. Then, I used that composition as a BG layer behind Allistair. I manually matched the BG plate to the camera movement of the original footage. (I didn't use motion tracking because the smoother result was more pleasing.) I added a little bit of grain to match the foreground footage. Since the camera didn't turn much, I got away with just having a flat BG map. That was a relief, making a spherical BG image would have taken considerably more time.

The final aspect was Calvin. I placed him in the shot using one from of the footage for reference. Since I already had the flat BG plate moving, I didn't animate the camera. That gave me a little time to enhance the rendering, so I did a couple of things to make it more realistic. First, I used a Photoshopped version of the BG image and mapped it to a sphere around Calvin. I turned on radiosity and ended up with a nice diffuse lightsource around him. I then made a relatively human shaped dummy and animated it moving past Calvin, matching Allistair's movement in the shot. The result is that Calvin recieved a nice shadow crawling over him. I have to say, I'm really happy with how Lightwave performed with this render. Not only was it quick to set up the 'dummy', but the renderings were under 3 minutes a frame. Can't complain!

And.. it's done. It is unfortunate that this shot was cut a little short in the final version of the movie, but I have to say I am quite pleased with what all I learned while working on this project. I have to say that After Effects and Lightwave make for a powerful duo. Not only did this project get done fast, but the results were quite pleasing. I really can't say enough about those two! It really is amazing what one can do with a small budget these days.

Any questions? Please, ask away. If you all find this interesting, I can write up some more about the other FX shots I did for this movie. And.. if you haven't seen it yet, check it out at http://www.rocketandco.com. You can watch it for free. Enjoy!

[Mark]

Excellent post there NanoGator. It's always insightful to see what others go through in detail when preparing a piece. Superb work too - especially considering the time constraints you were working under.

Kudos

[Zeeman]

WOW!!! I've actally learnt quite a bit through your post Nanogator! Thanks for posting this!!! :beer:

[hopesfall]

Awesome job man! Modeling Composition and all! I do have one question, you may have addressed it and I just didn't realize it; but how did you tackle the lighting of the model to match or fit in with the footage? Your model blends quite remarkably.

[NanoGator]

@Mark & Zeeman: Thanks guys.

@hopesfall: I lightly touched on this topic in my post, but I'd be happy to go into more detail. (Don't worry, I'm not the type to say RTFA!! hehe)

I examined the footage and developed a sense of what the light sources were on-set. The first big thing that caught my attention was that there were no harsh shadows. Everything was VERY soft. The second was that there appeared to be two really strong light sources. The first was the light that was behind the camera. (Either they had a stage light or they had the door open and it was a nice sunny day. I've actually been in a hangar before so that helped considerably.) The second light source was simply a strong ambient reflecting from all the walls and the floor. So I built a cube around the robot using a tiled image I made in Photoshop of the walls and the floor. I made it self luminous and turned radiosity on. In the case of the first light, I created a HUGE area light at approximately the right position that the light source in the footage was.

I also made a dummy model roughly shaped like Allistair and place it in front of the robot. I did this for two reasons: 1.) So I could cast a shadow of the main character onto the robot during the animation. 2.) So I could more accurately place the light source. The great thing about putting the actor in the green suit was that I could see shadows very clearly despite the light sources being so soft. That made a big difference.

There is one other thing I did with that robot involving lighting that I hadn't mentioned in my original article. He's using a reflection map I made as well. It's subtle, but it's there. That's actually where Calvin's specular highlights are coming from. (well some of them are coming from the main light source, but most of it is from the reflection map I made.) I've done a lot of work with spherical photography, so I put it to use here. I used a similar technique on this image here.

Any more questions? Fire them off!