Stefan Schlechtweg Tobias Germer Thomas Strothotte RenderBots-Multi-Agent Systems for Direct Image Generation. 137-148 2005 24 Comput. Graph. Forum 2 http://www.eg.org/EG/CGF/volume24/issue2/v24i2pp137-148.pdf db/journals/cgf/cgf24.html#SchlechtwegGS05