Distributed Procedural Creation Project

Introduction

Procedural Creation Project provides yet another way to create virtual-world contents, scripting all creation processes. The goal of the project, however, is not necessarily to replace the interactive creation, which is the standard way you have been already doing in modern virtual-world client software, such as SL viewer and its variants. Instead, the project will propose an entirely different approach for artists and designers to explore 3D drawings in procedural fashion. Also, it will bring a promising interface for scientist to visualize scientific data in a virtual world.
 

Example

The main component of Distributed Procedural Creation Project is a general purpose stack-based virtual machine, called PCVM (Procedural Creation Virtual Machine), which is implemented as a region module. Here is an example of PCVM code and its resulting images. The first one is Hello World! and the second one is simple coordinate axes to show the current coordinate. Because PCVM is a powerful higher-level abstraction of virtual-world content creation, any new functionality can be easily added to PCVM as a new operator. The third one is, for example, a teapot operator to generate an in-world instance of the Utah Teapot. Thanks to the stack-based architecture of PCVM, it is not pleasure that much for human-beings to write PCVM code by hand. Its architecture is rather intended to facilitate mechanically generating PCVM code. The forth one is a machine-generated maze. This is also an example of a distributed application using PCVM, that is, one machine mechanically generates a maze and injects its resulting data to another machine where a distributed PCVM-enabled region server is running.
 

Related Works

The MRM, Adam Frisby's recent work[1], will potentially overlap or even cover Distributed Procedural Creation Project. But, DPC is going to be completely separated from the existing framework, LLUDP and LSL. As mentioned above, DPC is currently working on a programming language interpreter implemented as a region module. Also, more interestingly, an instance of PCVM works as an Erlang node in its own right. In other words, distributed applications are fairly easily built using PCVM. Distributed Procedural Creation Project will be able to provide more powerful and general approach to connect in- and out-world. External Simulator Bridge[2] is an experimental region module to reflect external data source back into in-world states. DPC will cover most of its goals, too.
 

Architecture

As mentioned above, the heart of Distributed Procedural Creation Project is a PostScript?[3]-like, general purpose stack-based interpreter implemented as a region module for procedural creation. It is called Procedural Creation Virtual Machine (PCVM). You may think of PostScript? as a graphics format, or even some of you may call it more specifically a vector graphics format. But, neither description does not accurately show what PostScript? is. In reality, PostScript? is a full-fledged programming language. Even though it can be used as a general-purpose programming language, PostScript? probably best works when used to describe printed pages as it was designed.

Needless to say, PostScript? works in 2D graphics on paper. But, we have another dimension in 3D virtual world. What if a PostScript?-like programming language is offered in OpenSim? To open up that new horizons, I started this project a couple of months ago. As PostScript? draws on 2D paper, PC draws in 3D space!!

To provide a framework to build distributed applications using PCVM, an instance of PCVM works an Erlang[4] node in its own right. Erlang is a concurrent and distributed programming language originally designed and developed by Ericsson to build scalable, fault-tolerant, distributed telephony applications. Distributed Procedural Creation Project integrated Erlang.NET[5] into the DPC region module to enable an instance of PCVM to work as an Erlang node and communicate other Erlang nodes. It provides a powerful and general framework for PCVM to participate in distributed applications. Erlang.NET is also being developed and maintained by Distributed Procedural Creation Project.

Another motivation for Distributed Procedural Creation Project was Processing[6], which "is an open source programming language and environment for people who want to program images, animation, and interactions." For those of you who are experienced programmers, Processing might be less attractive because it provides only a small set of basic operations, all of which are nothing different from ones you have done in any other graphics library, for example, draw a dot, draw a line, put a color on them, etc. In addition, Processing is basically designed as a 2D application, although some extensions for 3D graphics are available. But, Processing has opened up another door and invited a large audience of artists and designers. Most of them were not computer programmers at first, but they have been creating a great number of great works using Processing, more or less in procedural manner. Look at a collection of works created using Processing[7]. I have a dream that one day a virtual-world exhibition for DPC artists will be held in a OpenSim? grid!

Future Works

The PCVM is a stack-based programming language interpreter. Thanks to its nature as a stack machine, instead of writing "1 + 1" in other standard programming languages, you have to achieve the same result writing "1 1 add". As you easily imagine, a slightly complex expression generates rapidly lengthy cryptic operations. Unless you are a pathologically enthusiastic computer programmer, the PCVM code is not at all a best choice for human-beings to practice a computer program. But, its simplicity is rather advantage to generate the PCVM code mechanically. The next step will be to write a PC library or even a PC compiler, so that you can write an equivalent PCVM code in other programming languages like C# in a more standardized way.