3D Graphics

Graffiti Analysis


Grafitti analysis is an interesting project by Evan Roth (and others) where he’s converting graffiti, or more accurately the motions which create graffiti tags, into data, which is then archived into a database and can be displayed as a 3d visualization. There are some interesting applications, but mostly I think it looks cool.


Diffusion limited aggregation redux

Over time people have been asking me to share the DLA compound I wrote waaay back. So here it is.


The compound can be found in the downloads section.

Diffusion limited aggregation is a natural phenomena in which particles in solution build up over time – as particles are deposited they limit the locations where subsequent particles can be deposited, resulting in a pseudo-random growth of deposits with characteristic nodules and ‘fjords’. You can see examples of DLA systems in nature all over, from veins of copper to urban growth patterns. In this simple ICE implementation particles are emitted from geometry and then pulled towards a “seed” point, namely the point cloud the compound is applied to. If there are no existing points in the cloud the first will be deposited at the origin. This causes DLA structures to build towards the provided surface and then to spread across it or inside it’s volume. The compound has a turbulence node which adds a random tropisim as well as a vector input for user-directed tropisims. Please be aware this was never intended as more than an experiment: it works fine but is a pretty simple implementation.

To use: apply the compound to a point cloud (typically with a single point) in a simulated ice tree… …

MSpro from XSI

Models in .obj format into XSI, then to MSpro for materials, lighting and a 5k render. The sculpture mesh is a full res scan, about as thick as a zbrush export with several hundred thousand polys.

Screen capture

More realtime test renders

Since I’ve been putting MSpro through it’s paces today, I decided to see how it did with a larger data set. So I fed it a reasonably large model of Manhattan. Mach Studio did great, export/import was fast, the machine was responsive, and even hitting it with realtime ambient occlusion, shadows and depth of field didn’t get the scene to a point where it chugged. Rendering this scene with similar settings in Mental Ray would have meant significant time per frame, certainly enough to preclude much in the way of any kind of immediate feedback. MSpro was fine onscreen and rendering 5k resolution images with settings turned up relatively high resulted in render times still under a half second a frame.


Not high art, but we’re talking test images people. I rather enjoy the simcity look of the orthographic one…Hey it looks like I nudged the ground mesh in one of those images. That would be a serious drag with a traditional render process, you’d have to submit it to the farm again. Realtime, it’s no big deal. Of course, there’s a lot of room for improvements on these images… the majority are not issues with the renderer but the artist (errr, me) who for some reason didn’t want to spend all night obsessing over test images. You can speed up render times, but there’s still tweaking galore. But at least you can tweak interactively.

Testing Mach Studio

Here’s the result of 1/2 hour (probably less) fiddling around with Mach Studio Pro and  Photoshop to try to see how fast I could produce an acceptable concept image.

I exported the buildings from Maya which took a few minutes, slapped on some materials, threw in an environment light and a spot light. Rendered a frame (which took 0.13 seconds to render) and took it into photoshop where again I just threw some elements together – a sketch filter blended with the CG, some vignetting and color manipulation. It’s not going to win any awards but that’s not the point… I was able to get this image out from start to finish incredibly fast, and that’s despite my being a novice with MSpro.  Very promising…

Gorillaz and Miku. Who can’t resist a cg character performing onstage? Not these people. I dig the leek-shaped lightsticks. (For the impatient, Miku makes her stage appearance at about 5:25 in this video.)

The mocap performance is nice I guess but what really interests me about Hatsyune Miko is that her voice is synthesized, not recorded. Would have been cooler if she was puppeteer-ed in real time ala Henson’s creature shop…

Update – no video available anymore, it was removed from youtube. Bah.

XSI toon shader

Did some more work on a basic realtime toon shader for XSI (and maya, it’s CGFX.) Here’s a sample…

Me. Me me me. Me too.
It's Agent Smith(s), toon style.

Functionality is pretty basic at the moment: Ink threshold, 2 levels of paint and a hard spec hilight, overall color control, a single point light source. I still need to introduce diffusion and spec mapping, possibly some reflections and bump/normal. Remember, if you see an agent, run.