Stefan Ihringer's Comp-Fu

TiefKühlKost – Fail

Stefan — Sun, 13 May 2012 20:45:03 +0000

Lecker

TMI Color Temperature Correction

Stefan — Tue, 08 May 2012 07:00:04 +0000

One of the things that I miss in Fusion whenever I have been using Nuke is a way to adjust colors using color temperature. Yes, there’s a white balance tool, but it’s a bit of a black box and it doesn’t have the kind of sliders known from Nuke (or even Photoshop’s RAW converter). I think Fusion’s tool is pretty accurate in terms of color science, but for eyeballing adjustments of creative tinting the other programs’ sliders are more useful.

Nuke provides the TMI system in its color picker so you can use it anywhere you see a color swatch. One parameter adjusts the color temperature by moving red and blue in different directions (you don’t have to specify a proper temperature like 5300K). The second parameter is a shift along the magenta/green axis.

Here’s a macro which allows you to tint an image using this system in Fusion. I don’t know if the formulas I’ve reverse-engineered are only used in Nuke or if there’s a standard for TMI (it’s kinda hard to find information about it). It goes without saying though that all of this is only valid in a linear color space. Reportedly it was also useful to cancel the effect of the ARRI Alexa’s white balance and CC Shift settings.

Download the macro here or view the help page on vfxpedia.

Immer die gleichen Filmplakate

Stefan — Sat, 05 May 2012 10:36:34 +0000

Kreatives Echo oder einfach nur einfallslose Grafiker unter Zeitdruck? Im (frankophonen) Blog von Christophe Courtois gibt es eine Menge dieser Collagen aus den sich ewig wiederholenden Bildmotiven, die für Kinoplakate in Frage kommen. 2 davon habe ich hier wiedergegeben:

Strand und große Köpfe in den Wolken: Der Code für schnulzige Dramen

Einsamer Krieger von Hinten mit seiner Lieblingswaffe

Die Plakate gibt es auch auf den folgenden Seiten gesammelt, wenn man sich nicht durch Christophe’s Blog wühlen möchte:

VFX Breakdown Effect (Breakdown)

Stefan — Tue, 01 May 2012 11:35:47 +0000

I was pointed to an effects reel for “Wrath of the Titans” by Method Studios (you need to watch it on YouTube due to the usual licensing issues):

Stills from a vfx breakdown by Method Studios (not my work)

The shots look cool, but what was more interesting is the way they did the breakdown of their CG elements. Look at the camera moves at 0:14 or 1:17.

I’ve tried to dissect their technique using a Fusion comp and some random model I’ve downloaded from turbosquid (so don’t tell me it doesn’t look as cool as Kronos in the video above). The way I think this was done was by projecting the rendered passes back onto either real geometry or a recreation of the geometry using a world position pass. The latter is the only feasible solution for scenes with a high polygon count and can also be done as a particle cloud (see the “dissolving” rocks in the stills above).

Then, additional footage is brought in on image planes. Whether the footage was a 2D matte painting to begin with or a CG element doesn’t matter, for the breakdown it’s all treated like a 2D element. You can see this on the flat volumetric godrays.

To spice it up even more, they probably rendered additional passes especially for the breakdown (for example the wireframe pass) using the camera move designed for the breakdown shot. At this point you could also re-render your scene’s FX passes using the new camera move and treat the breakdown shot as if it was an original shot Depends on how much work you wanna put into it.

Download the annotated comp (+ obj & textures, 1.4 MB)

Here’s a quick video that puts all the techniques together: particle cloud, projections, image planes and wireframe pass.

Mosaic Effect in Fusion

Stefan — Thu, 26 Apr 2012 20:20:18 +0000

I’ve recorded another video tutorial for your viewing pleasure. It’s just a tiny effect, but the video shows that you can take even little tasks like this a bit further.

http://www.youtube.com/watch?v=NL99jnhOzWk

Rocket Launch Reference Footage

Stefan — Thu, 19 Apr 2012 09:02:02 +0000

This is an awesome video about an impressive feat of engineering. But I don’t just love the video and it’s voiceover from a technology-geek point of view. It’s also a great reference footage for rocket exhaust and the mayhem it causes. I would love to see more science-fiction authors take this into account when they allow space ships to launch and land as effortlessly as a taxi pulling up.

Watch it full-screen and turn on HD 720p!

Here’s another one: The sound track of a ride on a space shuttle booster rocket from its launch to its impact in the ocean.

Thanks to my colleague who showed me the aptly-named tumblr page FUCK YEAH SPACE EXPLORATION

Correcting Rolling Shutter in Fusion

Stefan — Sun, 08 Apr 2012 23:27:16 +0000

eyeon has recently released its Dimension optical flow and stereo disparity toolset. I didn’t have a chance to test the stereo part yet, but since you can now calculate nice and crisp motion vectors, I’ve written a Fuse that can correct rolling shutter artifacts. Here’s a quick demo video:

You can get real-time performance on your GPU using OpenCL and as usual I’ve licensed my source code BSD-style if you want to tinker with it.

I haven’t had enough footage from different cameras to test the plugin thoroughly (just my iPhone and a Canon 5D Mark II). I also haven’t tested any other motion vector generators except for Dimension. Maybe Twixtor works as well, we’ll see…

Download the plugin here: RollingShutter_v1_0.Fuse or head over to Vfxpedia.
Photo credits for icon: CC-BY Nayu Kim

Google Maps 8 bit version

Stefan — Sun, 01 Apr 2012 07:51:07 +0000

Grandioser Aprilscherz von Google:

Verrückte Wissenschafter 2.0

Stefan — Mon, 19 Mar 2012 09:00:28 +0000

YouTube hat dem Typus “Verrückter Wissenschafter” eine Frischzellenkur verpasst. Der Bastelfreak von heute wohnt nicht mehr bei Mutti im Keller, er ist extrovertiert und präsentiert sein Kind im Manne vor einem Millionenpublikum. Vom Hobby-Pyromanen bis zum Waffennarr – hier sind ein paar Youtube-Channels, die mich mehr faszinieren als ich gedacht hätte:

Nighthawkinlight

Pyrotechnik und Druckluftgeschosse, mit denen man sich ernsthaft verletzen könnte:

http://www.youtube.com/watch?v=UslstxqrBlI

The Slingshot Channel

Jörg Sprave, der deutsche Steinschleuder-Enthusiast präsentiert sein Arsenal aus Holz, Stahl und Gummi:

http://www.youtube.com/watch?v=PYJ2zj1SB5Y

FPSRussia

Ich bin mir immernoch nicht sicher, ob das nicht alles ein Fake ist und von einem Waffenhersteller gesponsort wird… aber was solls. Waffen und Explosionen, was will man mehr:

http://www.youtube.com/playlist?list=PL9ED6B6AA7A8C2CDC

Doch halt, das Web gibt natürlich noch ganz anderen Wissenschaftlern eine Plattform. Die Macher hinter den folgenden Channels schaffen es, Wissenschaft für eine Generation spannend zu machen, deren Aufmerksamkeitsspanne die Länge einer SMS nicht mehr überschreitet. Ich finde, diese Videos erreichen mehr als ein Jahrzehnt “Mediengestalter” mit ihren Lern-CD-ROMs…

Minute Physics

Häppchenweise Quantentheorie in einer Minute und mit Filzstift:

http://www.youtube.com/playlist?list=PLED25F943F8D6081C

TED Education

TED, die Konferenz mit den Vorträgen, die tiefgreifend und verständlich zugleich sind, hat sich mit Animatoren zusammengetan. Das Ergebnis sind Wissenschaftshäppchen, die die Neugierde von Schülern und Studenten wecken sollen. Hier ist ein Clip mit Adam Savage (Mythbusters):

http://www.youtube.com/watch?v=F8UFGu2M2gM

NASA

Und zum Schluß etwas Entspannung mit den beeindruckenden Aufnahmen der NASA:

http://www.youtube.com/watch?v=FG0fTKAqZ5g

(Aufmerksam gemacht auf die letzten paar Videos hat mich Dropping The Science)

Syntheyes Lens Distortion to 3DEqualizer

Stefan — Fri, 16 Mar 2012 20:08:00 +0000

I’ve crunched a few numbers yesterday and I think I came up with a solution to convert the lens distortion coefficient calculated by Syntheyes to the one used by 3DEqualizer.

This is necessary since up until now, Fusion’s native LensDistort tool only supports the latter. Unfortunately, only the first coefficient can be used since 3DEqualizer’s formula differs for the higher order coefficient. You can download a tool script that does the calculations for you here:

LensDistort for Syntheyes.py

Here’s the math behind: