Voronoi playtime, redux

In a previous article I showed how some hidden functionality in Blender's distributed OSL headers could be used to create all sorts of Voronoi/Worley noise. At that point I left out the choice of distance metric because there wasn't a nice way to implement choices in OSL.

There still isn't but prompted by a question I decided to implement it in an ugly way; after all, if it works that is all that matters :-). All the necessary code to implement different distance metrics is already in node_texture.h but for some reason it was commented out. I therefore lifted the necessary part from this file and combined it with a a small shader that lets you choose the distance metric with an integer. An example for the Manhattan metric is shown below.

Node setup and code availability

The node setup used to generate the image above looks like this:

The code for the shader is available on GitHub. The node it generates may look a bit different than in the noodle shown here because I added an exponent input E that can be used for the generalized Minkovsky metric (metric == 6).

If you would like to know more about programming OSL you might be interested in my book "Open Shading Language for Blender". More on the availability of this book and a sample can be found on this page.

Greebles in OSL

The shader that is presented here basically takes as input a set of uv coordinates and produces a set of rectangles, each with their own uv coordinates. These rectangles are randomly distributed and rotated and do not necessarily cover everything: the fac output signals whether there is a rectangle or not.

With this set-up you can for instance cover a surface with random hull plates or similar:

The noodle used to produce the image looks like this:

There are two OSL shaders in this noodle: the first one on the left is called Greebles and is the one that divides up the coordinate space, the second one is called Rivets and is part of the green Rivets material layout. That last one simply distributes small circles around the edges of a rectangle.

Both shaders are available on GitHub, Greebles here, and Rivets here.

If you would like to know more about programming OSL you might be interested in my book "Open Shading Language for Blender". More on the availability of this book and a sample can be found on this page.

WeightLifter add-on: new feature release

Version 20150501170240 adds two new modes: one that assigns values based on the average area of the faces sharing a vertex and another mode that assigns values based on the variance of the lengths of edges that share a vertex. The first one I find useful in creating materials on organic shapes that vary in a subtle but correlated manner while the latter offers a complement to the curvature mode, highlighting certain vertices in a different way. Of course you might find a completely different use for it, that's why I include it in the add-on :-)

The new version is of course available free of charge to people who have already purchased the add-on. Check the BlenderMarket page for more details.