Arsenal   Virtual Reality Systems

 
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please, visit our YouTube channel where You can find some computer graphic animations and videos taken from our proprietary immersive Real Time navigation system.

Stereoscopical walktrough.

 

Technologies
  • Open Scene Graph
  • CAD, 3D Graphics and animation
  • Stereoscopic visualization

Open Scene Graph

Virtual Reality projects are almost always unique and complex, because of the number of variables present in the same reality that it is to be simulated. That explains why there are not user-friendly applications, as there are for word processing or photo retouching. Virtual Reality projects are realized in programming environments, where the resources are specialized libraries, that require the creation of software code. These environments can be either proprietary or open source.

Arsenal, after having employed commercial tools such as WorldToolKit by Sense8, has then adopted OpenSceneGraph (OSG), an open source software, to the development of which our company cooperates actively with its own resources. The reasons for this choice have also been, besides the particularly interesting characteristics and performances of OSG, the opportunity to have the complete control over the development environment. OpenSceneGraph has been adopted by important organizations, such as N.A.S.A. for the visualization of the Earth, and industries such as Boeing for the flight simulation.

To know more about OpenSceneGraph: http://www.openscenegraph.org/index.php

CAD, 3D Graphics and animation

All Arsenal projects include the development of 3D graphics. However, the different applications impose different philosophies on the creation of 3D models.
For Virtual Reality applications, where it is required that the rendering (computational process that produces images starting from a geometric description) occurs in real time, care must be taken in order to keep the complexity of the created geometry low. This technique requires a deep knowledge of the 3D rendering rules and the standards on which it is based (OpenGL), the GPU (Graphics Processing Unit) internals, and of course a real experience acquired over the years.

The situation when a Video, to distribute on CD-ROM or DVD, is to be produced is different. A video, since it is not interactive, has just to display images generated previously through a rendering process that can take all the time needed, usually many hours or days and on many computers connected with each other. The advantage of the video is therefore the absence of limits in the geometry complexity, with a consequent better image quality than the Virtual Reality’s, quality that can reach the hyper-realism. On the contrary, the video does not allow all the flexibility of Virtual Reality systems.

Despite the two different applications described, the tools used for the creation of 3D models are the same. Rhinoceros3D, a CAD software particularly suitable for realizing models with complex surfaces, represents the first step. This CAD is indicated for architecture, marine design and mechanics projects. It is also able to provide instructions directly to the machines for the numerical control manufacturing (i.e. milling machines) and to the machines used in stereolithography, the technology for the creation of extremely accurate solid prototypes obtained by building up thin layers of resins.

Rhinoceros3D is a real CAD for the designing. For the 3D modelling of organic forms we use Lightwave3D Modeler, a software that also allows to give the surfaces the desired aesthetic characteristics. Modeler is particularly suitable for archaeology and character animation.

One of the techniques we employ as support to object measurement and 3D modelling is photogrammetry. Starting from pictures, a solid model of an object is obtained through a software based on trigonometry. For the photogrammetry, Arsenal employs RealVizImageModeler.

Stereoscopic visualization

The stereoscopic visualization is one of the main characteristics of Virtual Reality. The vision acquires the sense of depth with the employment of goggles, sort of glasses with polarized lenses, that can be either passive or active. The stereoscopic system provides the right eye as well as the left one with their respective perspectives. The stereoscopic visualization obviously requires a specialized hardware. To achieve acceptable performances with the stereoscopic projection the hardware costs are really high, some tens of thousands euros.

The stereoscopic projection can be applied to Virtual Reality applications as well as to videos. As for the Virtual Reality, the real-time rendering doubles the amount of resources requested to the GPU (Graphics Processing Unit), that has so to be of a special type and very powerful.

Arsenal can realize stereoscopic videos with Lightwave3D Layout.

Stereoscopic Virtual Reality applications are developed in OpenSceneGraph.