queo blog – Das Blog der Spezialisten für kreative Werbung, ganzheitliche Onlinevermarktung und individuelle Softwarelösungen. » Second Life

3d module process

Thomas Gründer — Fri, 31 Aug 2007 11:38:44 +0000

Finally, here is the current progress on the 3d module of SUSL. I have finished the class diagram and a description of the algorithm to explain the structure and the way I hope to find SL-Primitives in a 3d mesh. The diagram is not very exact, I used it to structure my thoughts and group the elements I need.

I will try to explain the algorithm. I hope it will be comprehensible. If not, tell me and I will explain it more deeply.

What elements to use?

SL Primitives are geometric primitives like cubes, spheres and cylinders. To find them in a mesh you need to specify them independent from size, rotation and position. Therefore I define topologies to describe the primitives. A topology consists of elements and neighbourhood relations between elements. For expample: you have an edge and it is connected to another edge orthogonally. To optimize the SL Primitive count I will not use edges but introduce “pieces” which are the smallest units in a topology but may contain several edges. Other elements are curves and faces. With those elements you are able to define the abstract primitives.

How to find those topologies in a mesh?

First the program will retrieve all edges from the Sketchup Model. It will take every edge, try to expand it and search on its basis for possible topologies. To expand means that the program will look if the edge matches a piece, and if there are other edges which elongate it. The piece and its neighbours are the starting condition for the topologies. If they match the topologies, they will be saved in a dynamic list with the piece, the state and the topology. The state defines the completion of a to-be-completed-topology. Afterwards every item of the dynamic list will be further processed step by step until the topology cant be further processed, or the topology is being completed.

The Description is simplified, but those are the main ideas.

SUSL architecture

Thomas Gründer — Sat, 07 Jul 2007 10:35:38 +0000

After having verified the tools we will use, we started to analyze and design the SUSL project. Our approach on SUSL is a kind of three-tier-architecture. We use an input layer which is represented by the SketchUp framework. You are able to import various data types and SketchUp represents the mesh data in a 3D environment. Furthermore there is the processing layer. It is constructed modularly so that you are able to add new modules like a sculptie module. You need to create a new folder in the “/plugins/susl/” folder of SketchUp. After creating a “*.susl” file you only have to define your methods. The 2D and 3D Module are the ones we will implement in our thesis. The modules are able to write onto the third layer, the Second-Life-export-layer (output layer). A SL-container will be filled with SL Primitives by the modules. The export layer has to verify that no Second Life restrictions are violated (like 10*10*10 m restriction, 16kb script restriction and stuff like that) and it has to write a file which is copied and pasted into Second Life.

Progress on SUSL

Thomas Gründer — Tue, 26 Jun 2007 17:22:30 +0000

This is our current progress in the 2D Module. You are able to let SketchUp build up walls out of edges and export them into a text file in the SketchUp working directory. The script is “Copy & Pasted” into Second Life. Now you only need to touch the “Builder” and it will build the ground plan to walls. It is a prototype to test the technologies we like to use. Here are the pictures: