The Pixel Crush

-------------------------------------------|Digital Animation & Game Criticism|-------------------------------------------

Monday, 13 May 2013

Pixel Cobbler II: Silicon Scissors

Brace for flowery language and motion blur.

The much anticipated Cornish roller derby documentary, Low Down & Derby: The Documentary (which you can follow here and check out the official website for here) is coming to completion under the supervision of virtuoso director Jennifer Rollason. My role has been to complete a title sequence that is both informative and spectacular, animation style, and the deed is done.

I started months ago in January making the boot for the skaters and since then have been on and off making progress, much more on than off in the last 3 weeks. At the end of March I had this ricketty animated block through that illustrates my suspect attempt to turn roller derby into Grand Prix with whip pans and close ups of wheels. Fortunately, most of that stuff didn't survive after a well aimed blow of directorial feedback. Here it is for the sake of demonstrating how it evolved:

The directorial vision specified a side on camera angle that followed the pack in one long tracking move showing the jammer making their way through the middle. So I hastily re-animated and created a placeholder skater for clarity's sake. Five days later it looked like this:

There are a few techniques of note I want to detail.
1. Creating Super Detailed Geometry From Curves Taken From An Image
The skater was made using a workflow inspired by- read 'stolen from', Aardman's Staves music video.
An image is taken and the outline is selected, that selection can be converted to a path in Photoshop, that path can be exported to Illustrator, it is now .ai file that Maya can read as curves. From said curves a plane can be created by choosing surface/planar/ and selecting polygons. Or something like that. Now you can extrude that polygonal surface and you have a detailed outline with some thickness. Now proceed to spend days trying to unwrap all the edges so you can tile a corrugated cardboard texture along them that is only visible in shot when something rotates towards camera.

For example this text started when it leans forwards...


...displays its true cardboardy nature. Though this didn't stop most people identifying the cardboard as wood. Fools.

Also if you're curious as to what proper motion would look like on that same frame then see below, but deadlines dictated that 33 minutes per frame was unacceptable, though considering it was only actually a 10 minute increase on a complex scene it mental ray's new unified sampling is actually pretty impressive, if you're doing heavy raytracing, you also get a boost in image quality too, providing its not too grainy.
Motion Blur!
2. Using IES Profiles To Create Uber Realistic Falloff On Lights Like REAL LIFE!
IES profiles are lighting information captured by light bulb manufacturers and can be read by point lights in maya, I'm assuming only point lights are compatible because point lights cast light in all directions and the light data is 360 degrees and three dimensional? The light profile (which can be downloaded and viewed for free and with free software like IES viewer) then aligns itself with the point light's -y axis: so by default its pointing straight down. Here you can see the falloff as the light casts a kind of ringed effect across the card like that of a torch, creating a home-made punk aesthetic enhanced by my lovely duct tape that evokes derby culture.

 3. Using Extreme Mental Ray Rendering Features Like Environment Lighting
These fantastic scripts from the Elemental Ray blog expose some of the really cool hidden features mental ray has but aren't accessible in Maya by default. This includes the environment lighting mode that allows for an HDR to be used to light the environment extremely realistically, also generating detailed reflections as well as seen in the glossy wooden floor below, this takes the emphasis off blotchy final gather and allows most of the lighting to be raytraced.

 I played with the quality of the floor quite a bit, going from very glossy to a more scuffed and matte looking thing.

This is what it looked like before when I nicked it straight out off the old roller derby promo, which still looks great, but not so much from the angle that it was going to be viewed in the title sequence so I retooled the shader and tiled all the textures.

Something that was a bit of a conundrum was getting the lighting to look good considering the angle I'd chosen, I wanted to light it from above like a large snooker table light, because I loved the look of this reference I'd dug up:

The problem with that was that I was lighting thin cards, that catch almost no light from above, as seen in this early render:
I ended up sort of solving it by using spot lights in conjunction with area lights to light the tops of the cards and get a nicer penumbra on the ground, then I increased the bounce light coming from the track to better light the bottoms of the cards and create that bright miniature look.

4. Creating An Enormous Crowd In Compositing Because RAM Is A Thing You Never Have Enough Of
I couldn't have the size of crowd I wanted in Maya, it just wouldn't handle it. So I made a long string of people populating the crowd and rendering it at 8k (8192 X 8192 pixels, imagine the kick I got out of that) and started laying them out in 3D space in After Effects. In order to get the crowd to move with the render from Maya I was able to export the camera from Maya as a .ma, once I'd got the right frame rate and baked all the keyframes (which was more awkward than it should have been because of the weird parenting constraints of the camera shake script I use). Then I could have the rendered and composited crowd move in perfect synchronicity. The entire crowd in the shot below is comped from 2D images. One thing that was a little tricky was recreating the zdepth for this crowd so that the depth of field effect smoothly transitioned between rendered and comped footage, but in the end it was just a case of layer gradually darker greys back across the crowd.

And here are some pictures I don't really have any words for. Check out the scratches on this wheel.
Juicy SSS Rubber Wheels

Smouldering Metallic Reflections
So now everyone can await the documentary proper with appropriately high levels of anticipation. Thanks for making it to the end of possibly my longest post, ever.

Sunday, 5 May 2013

Pixel Knitting II: Sty Dive

You know what's rubbish? Having a blog I used to be proud of and neglecting it for several months. That's awful, especially when theres a ton of things I want to share. So hopefully this is the first of five or more semi written blog posts.
This is Shaun the sheep with no arms. Why does he have no arms? Because part of the magic CG is that we can just turn things on and off, like arms. Find the arms button, turn it off (its not that simple). Part of the fancy animation for the Sty Dive game was that Shaun's arms waved independently of his body depending on the angle he was falling at.

One of the great things about using Vray is the way you can easily isolate parts of the render using object properties and render elements, simply grouping them in the outliner and changing attributes that effect multiple objects. Not just alpha attributes either, GI, shadows, reflections, all the control is in there.

Here's a composited frame of Shaun's in-game animation where surveys the height before diving.

I tried a couple of different lighting setups, above being closer to the final one as it has cooler shadows giving a better sense of Shaun being higher up in the blue sky than the one below where the green bounce light from the grass makes him appear too grounded.

When Shaun plunges into the bucket at the bottom of the dive he needed to emerge with a victorious grin so I created some alternate shaders to make him appear nice and wet from the water he'd just been submerged in. 

The mandatory glitch render, don't even know how this happened:
a table for some moles to sit behind as they judge Shaun's diving performance.
We got some feedback, always good, and the general consensus was that the blue goggles I had made weren't comical enough, and admittedly they were more surgical than athletic in appearance. Also the refractive index on the goggle lenses is too high as it makes Shaun's eyes appear like that of a person with severely deficient eyesight.

So we had a look at the series for reference and came back with this fantastic flowery showercap and pink snorkel combination!

The problem with writing these posts so long after the subject of the post has actually taken place, is that they become rather light on prose- due to the fact I can't remember what I would have said. This arguably improves the blog. Perhaps I should dedicate more time to presenting these posts as visual pieces that comprise multiple images rather than talking about the technical details of how I moved this vertice or rendered that pixel. I never felt I was really educating anyone anyway, if people like the work and want to know how to achieve a specific effect they tend to just ask me.


Pixel Propaganda
How do you summarise or collect months worth of reading into the appendices of a blog post? You don't, we're starting from scratch. Mostly because I stopped collecting material for this segment a long time ago when I realised that posts had become too infrequent to warrant any kind of literature curation. So here is the residue and then we can start afresh:

Here is a video from the game jam back in January, I have make a cameo appearance a couple of times and its great to see some of the other jammer's work in progress.

One of the more interesting game bloggers wrote an article regarding the fine line between advocating diversity in the representation of minorities in media, and promoting censorship.

One of the games I've been playing more of than any other recently is actually a Japanese role playing game, a genre I usually avoid. But Persona 4: Golden is a real revelation. Imagine The Sims meets Pokemon embedded within a high school murder mystery where the lead characters can explore an alternative reality. Its cleverly designed with all the core themes being systemically represented. The writing is great, very very funny in places, and characters face their personal demons down during gameplay. Here a couple of great critics exchange a series of letters exploring its finer points.

And lastly, on a more CG note, if you copy these scripts into your scripts folder and you're running Maya 2013 (it may be compatible with other versions this is just the one I've got it working with) then some of mental ray's more powerful and exciting new rendering features are exposed in the render settings window. Things like unified sampling and environment lighting are all easily accessible and great to use. As explained in elemental ray's great post linked above. They help bring mental ray's feature set more in line with some of the standard stuff I've come to expect from lighting and rendering in Vray.