Yesterday I added a new node to Blender’s compositor: Displace. It works very similarly to Shake’s iDisplace node, pushing pixels around based on an input vector mask, and is useful for all sorts of things like doing hot air distortion, quick and dirty refraction effects in post, and so on. The full documentation is in the commit log, I guess I’ll have to tidy it up for the release notes.

One curiousity of this one is the technique used to code it. Most of the code logic was done using Blender’s Python Image API, as a means of quickly testing and prototyping. Python is a lot slower at the actual processing, but it’s a heck of a lot quicker to test than having to compile Blender each time. I recommend it!

You can download the prototype script/.blend file if you’re curious (just press Alt P). I then ported to C, which is relatively easy to do for simple image processing code like this, and changed a few things around. Previously in the Python version I had to try and come up with my own not-too-bad antialiasing code, though I’m sure what I came up with has been done before and has a nice technical name or something ;) In the C version I was able to use some nicer image sampling code that Ton used for the awesome Map UV node. Incidentally, I also used the same Python prototyping technique for the UV test grid option when creating new images in Blender (.blend file).

Last week, my ADSL2 modem bit the dust and until my ISP sends me a new one, I’m disconnected from the net - I’m posting this from an internet cafe. Of course, thanks to the christmas/new year break it’ll probably be a while before I get connection back again, so if I take a while to reply to email etc, that’s why, and I apologise!

Hope you’re all enjoying the holidays, see you back online soon.

Edit, a few hours later: Scratch that, I arrived home and there was a nice working modem waiting for me. Yay!

A few pics of Tokyo through a fisheye lens, from November. I’ve also discovered the awesome new geotagging capabilities on flickr. It took an evening to go back through most of my ~400 shots there and drag and drop them to the locations around the world that I remembered on the map, but damn, it’s a fantastic feature.

When I worked on adding tablet support to GHOST, Blender’s low-level input system (alongside Nicholas Bishop and Andrea Weikert who did the X11 and Windows versions), one thing I had in mind was the possibilities not only in the obvious painting and sculpting, but in other more experimental areas too. I’ve got a few ideas sketched down about potential uses in the interface, for example imagine sliders that changed in precision depending on tablet pressure, or a radial menu that uses the tablet tilt information to bias what option is selected.

A tablet, especially one that supports tilt sensitivity like the Wacom Intuos, is almost a poor man’s 3d input device. With X/Y location, pressure and tilt, you can derive a lot of information about the pen’s situation in 3D space. This is interesting to me, because unlike real 3D input devices like spaceballs (which I don’t own), many CG artists have tablets, so input methods involving a tablet can involve a much larger audience than the more obscure devices, and so investigating it doesn’t feel like such a waste of time :).