Matchmoving, Motion Graphics and Dubstep

Nuke’s Smooth Ramp Functions

Nuke’s Ramp node can produce linear and smooth gradients. Here are its formulas. I have reverse-engineered them by trial and error after reading up on interpolation formulas like smoothstep (nicely summed up on this website).

In these formulas, “x” denotes a value from 0 to 1. The result falls into the [0-1] range as well and needs to be scaled by the desired end color if you want an RGB ramp.

// linear
y = x
// plinear: perceptually linear in rec709
y = pow(x, 3)
// smooth: traditional smoothstep
y = x*x*(3 - 2*x)
// smooth0: Catmull-Rom spline, smooth start, linear end
y = x*x*(2 - x)
// smooth1: Catmull-Rom spline, linear start, smooth end
y = x*(1 + x*(1 - x))

Here’s a ramp macro for Fusion which allows you to draw ramps directly onto an image like in Nuke. Fusion’s own BG tool is of course much more flexible, but it requires you to merge its gradient manually and it has no easy switch for smoothstep gradients.

Ramp_v01.setting

Compositing Tutorial Part 2

Here’s part 2 of my compositing tutorial series. It’s still about tweaking the camera move of our turntable shot. This time, I’ll demonstrate some expressions to retime one camera move based on the angle of another one so the projection’s distortion is minimized. You can grab the comps and footage on my tutorial page.

Using these techniques, you can integrate matchmoved footage into modified camera moves. This may be necessary because there were problems with the camera move on set (bumpy, wrong pacing, …), the director changes his mind or the intended camera move wouldn’t have been possible in real life.

I have employed this technique on the EXPO project. The scene can also be found at the end of the tutorial video. The actor was shot on a turntable and the camera move went like this:

• pull camera away from actor
• rotate actor by 90 degrees
• dolly in

Of course this makes for a really crappy camera move if you add a CG environment since it’ll look nothing like what a real camera crane operator would perform. The final shot was designed in 3D so the plate that was shot had to be integrated somehow. I had to cut out a piece of the original plate, luckily for us the actor was sitting still. After a bit of additional 2D stabilization (the matchmove wasn’t that exact apparently) the plate matched perfectly.

Christmas Card Origami Animation

Excellent full-CG piece:

I suspected the snow globe to be CG but throughout the video I thought that the animals around it were stop-motion origami sculptures.

See more work from the artist at mono-motion.com or visit the flickr album for work-in-progress screenshots.

Python & Fusion Video Tutorial

I’ve finished another video tutorial for Fusion. It covers Python scripting and takes a look at the object oriented model of controlling Fusion’s tools, querying their attributes and setting keyframes.

Download the script that’s shown in the video.

Vertical Alignment

I’ve finished another quick video tutorial, this one is about vertical alignment in stereo shots. It’s done with Fusion but this technique requires no plugins and can even be done in Photoshop 🙂

• Download annotated comp and images (zip)

I have enabled Youtube’s automatic transcript just for the fun of it. It used speech recognition and it’s funny how some phrases are transcribed perfectly despite my German accent while others are jibberish. You can download the subtitle file though and it only takes a few minutes to edit the transcript and re-upload it again.

So enjoy the English captions on this tutorial! Here are some funny phrases that Google’s voice recognition software had produced initially:

0:00:09.809,0:00:14.019
as you probably know there are lots of things that can give the bureaucratic when it comes to stereoscopic footage

0:00:14.019,0:00:17.960
the most important one is spiritual alignment

0:01:05.239,0:01:07.340
the monogram version wants it

0:01:20.080,0:01:22.230
his foreign troops of the ride i

0:01:35.240,0:01:38.929
since the transform which is his offspring you have to hold down the
aisle to key while driving the mention of your porch

0:02:48.259,0:02:55.259
now zoom back into the top left corner and adjust the anglo french haitian

0:02:57.629,0:03:01.020
using the cursor keys left and right then
you can get justice in smaller steps

You tell 'em, Sly!

Multiple Camera Projections in Fusion

Made another video tutorial about combining projections from multiple cameras. Enjoy 🙂

Also, check out my script to quickly align image planes to points in a point cloud and my latest tutorial about camera projection workflows.