As far as the release itself goes, here’s another little list of my favourite contributions this time around.

• Tapering 3D curves with radius per CV, with shrink/fatten tool
• Tablet pressure and tilt support in Mac OS X, and tilt support in Windows and X11
• New UV test grid generated image, designed to be easier on the eye and to show distortion clearly
• Proportional edit mode random falloff option
• Object level view/select/render restrictions in the outliner
• Upgraded the User Prefs OpenGL lights section to use nice modern vector and colour picker UI controls
• Dynamic icon fie loading and themability
• Compositor Displace node, Combine RGBA node

There’s one bit of disappointing news though. The next release was planned for a while to be a UI-centred Blender 2.5 release, for which Ton would do the huge and time consuming necessary internal upgrades that would allow features that I’ve been working on such as drag and drop in the outliner, a customisable toolbar, and radial menus to be implemented.

It seems now that once again, it has been decided for this work to be postponed in favour of a version 2.44 with smaller projects, meaning that it’s going to be at least May or June before any of these UI projects can be integrated. It’s a lot of difficult work for Ton to do, and it’s up to him to decide what he wants to work on, but it’s also frustrating and demotivating for me, because I’ve been waiting so long, being prevented from working on these sorts of improvements release after release. I offer my apologies to any of you who are waiting too.

This is quite simple to rig up in the compositor, below is an example with a deliberately grainy and blurry render to clearly show the effect of the unsharp mask.

Now that I’ve got an unsharp mask, it’s easy enough to follow through and look at implementing some of the techniques mentioned in the paper. One that interests me the most is where they use the depth buffer to give a kind of ‘drop shadow’ behind foreground objects, using the unsharp mask to find discontinuities and and mask foreground/background. This can be used like a fake, post-process ambient occlusion. With a low radius, it can be used to act like a dirt shader, darkening cracks and wrinkles, and with a higher radius it can act more subtly on larger features.

Below is an example of using this fake AO technique. I didn’t actually use this on the Waiting in the Basement image, but the model is a nice test case. I start by finding the creases and corners from the depth channel using the unsharp mask, then I do some tweaks to the intensity since what comes out of the unsharp mask isn’t immediately useful by itself, and doesn’t cover all the areas I want to darken. Because it’s using a non-antialiased Z buffer, I do some small blurring to the mask at the end to make it a bit smoother, and then use that mask to darken the image slightly, giving the detail shadows.

Note that I’m using the Min and Max options on the Map Value nodes to clamp the channel to between 0.0 and 1.0 before blurring. Since the channels are all float values, giving a range greater than 0-1 can make the blur nodes work in strange ways. The effect is much clearer on the full size image, especially around the collar and folds in the face, so click to check it out. Here’s the .blend file (2.43 RC+ required)

(click for full size)