blender

SabakiThemes Blender Directory

This folder contains the resources used to make the themes, including the blend file.

Notes on the Blend File

SabakiThemes.blend requires Blender 2.93.3. It might work with earlier versions but I haven't tested. The renderer is set to "Cycles".

The project is heavily reliant on linking objects between scenes to avoid duplication of resources. This saves some space but primarily allows editing of shared resources to benefit all of the users of those resources. In particular there are only three stone meshes: a single-convex Yunzi, a bi-convex Yunzi and a Japanese-style shape with a sharper rim. The various stone objects share those meshes (see Duplicate Linked) but have their materials linked at the object level (see Data Block) so they can vary. Likewise there is only one board mesh shared by the various board objects which provide the varying materials. Finally there are only a handfull of cameras, a couple of different ones for the backgrounds, one for the board, one for previews and one for the stones, these are directly linked between scenes (see Link Object to Scene).

There are four scenes per theme: "ThemeName Preview", "ThemeName Background", "ThemeName Board" and "ThemeName Stones". Scenes comprising a theme share a common HDRI environment in their World Properties for consistent lighting. Each scene nominates its preferred camera in its Scene Properties.

Each scene is rendered with a compositing phase that uses a File Output Node to write images directly, saving development time.

The "Preview" scenes render two stones on their board with the prevailing lighting, in order to see how the shadows should look when making adjustments to the css for each theme. See previews for the results.

The "Background" scenes are the most varied as some use a simple plane with a carpet texture, while others use a tatami mat that I pulled in from an earlier project. They also link one of the cameras.

The "Board" scenes just contain a board and a link to a camera. The materials for each board are collected into a node group so they can be re-used by their sibling "Stones" scenes.

The "Stones" scenes contain the stones, a board and a linked camera. The film setting for the stones theme is transparent meaning the background behind the rendered stone image will be transparent. The board material is interesting, it uses its sibling "Board" scene board node group but mixes it with a holdout shader with the mix factor determined by a light path node's Is Camera Ray output. The upshot of this is that the board is invisible to the camera but still causes specular and diffuse reflections on the stones. Each stone has a separate View Layer (actually there is a separate view layer for each stone and all other stones are disabled from that layer). The compositor sends each stone image to a separate file.

Gotchas

I thought I had found a bug, and even reported it to the blender developers, who kindly explained it was actually behaving as expected though it is confusing, so I thought I'd share: In the properties editor, in the Material Properties tab, the Material Slots are owned by the mesh, not the object. Each slot then nominates wheter the actual material it refers to belongs to the mesh or to the object. This means that if you attempt to remove a material from an object by clicking the - button in the material slots tab, you'll remove it from all objects that share that mesh. Instead you should remove or replace it in the linked material field immediately below.

make-seamless script

After rendering out a board or a background, you'll need to make it seamless (tileable). You can use Photoshop or Gimp or possibly many other tools to do this, but if you have Gimp installed you might be surprised to know that it is scriptable and can be run in batch mode. I'm on a Mac but this should work fine on Linux, and shouldn't be too hard on Windows using this as an example:

• Copy simple-make-seamless.scm to your gimp scripts directory.
  • For me that's ~/Library/Application\ Support/GIMP/2.10/scripts (I had to create the scripts directory).
  • On Linux I beleve it's ~/.gimp-<version>/scripts.
• Edit the make-seamless bash script and change the path to your gimp executable.
• You should then be able to run ./make-seamless path/to/your.png to transform the file in place.