Monday, May 30, 2011

Portal 2 P-body

First off, major props go out to CGJeff ([url=http://www.cgjeff.com/]Cgjeff.com[/url]) for hooking me up with a textured model from the game.  It's proven to be an invaluable asset and reference for this project.  I've also commissioned him out to print out some of the more intricate mechanical parts for this fella and from what I've seen so far he does great work.  If yall need something printed, he's a wizard with a Reprap.



I ended up settling on a scale of 72" inches for this fella, even though his in game scale puts him at 79".  I'm just pushing 6' and the proportions of P-body give him a LOT of leg, so I scaled him back slightly in order to make this puppet manageable.  P-body will be a "bunraku" style puppet, where the main body will attach to a harness, and I'll be controlling the arms and legs with control rods, servos, etc.

Here's the main body for P-body hot off the mill and coated with onyx for structure and a smooth surface.  You can see the 2" slice layers in this first shot fairly well. Originally the plan was to build up a hardcoat and call it a day, but I've been having trouble with delamination and airbubbles warping the skin.



Then the torso got a liberal application of apoxie sculpt and primer, and was sanded down again.  I propped up the eye piece in there to see how it might look once it's fitted in and working.  Turns out there's a lot of intersecting geometry in this area which really came back to bite me in the ass while working on the animatronics for the eye as we'll see later.







Next, Volpin gave me the bright idea to melt down the pink foam innards and backfill the body with resin to strengthen the piece and reduce flex and delamination in the skin.  To his credit, it's a great idea in theory, but my execution left me with a ton of air pockets and voids between the outer skin and the backfill.  The next couple days were spent gouging out these pockets and filling them in with bondo.  At this point the torso is probably more bondo than resin, and it's starting to get pretty heavy.  Once I get a decent finish on this piece, I'll do what I should have done to begin with and just mold it and pull a strong, lightweight cast in fiberglass. 



I took a cue from the disaster that was the upper torso and went ahead and molded the lower portion from the outset.  Fun note - All of my molding so far has been done using silicone molding products from Wal-Mart.  At 2.68 / 10oz tube, this has been a fantastic money saver.  It's a little difficult to work with, but once you get the hang of the workflow and ratios of acrylic and glycerine to add you can get some fairly decent results.  Obviously you're not going to get smooth-on quality from this silicone, but at 1/5 the price, it works just fine for me.





Along with the torso I've decided I'd like to have an animatronic eye that I can have track around and (if there is time) blink.  I can't seem to find the original video to upload here, but I did have it posted up to my facebook prop page - Animatronic Eye Proof of concept




The servos are controlled with a 2 axis thumb stick running through an Arduino board.  I can't stress how much fun it was learning and playing with the Arduino.  It was super easy to learn and is a very robust platform for protoyping near bouts anything. 


Here's a quick shot of the lower leg shell cover.  It's nothing more than the milled parts coated in a bit of leftover onyx.  It has since been molded/cast/cleaned up/remolded, and is now ready for to have fiberglass laid in it for the final piece.  




I've noticed that I am notoriously bad at not documenting my work.  If a picture is worth 1000 words, I'm going to need to write a lot more about this build to make up for my lack of pictures.  This week I'm making an honest effort to keep the camera in the shop to keep up to date on the build.