A Methodology for the Semantic Visualization of Industrial Plant CAD Models for Virtual Reality Walkthroughs

Abstract

There are still many open questions and needs in important aspects of the scientific area of Large Model Visualization LMV- for Plant Design. Performance to achieve interactive rates in immersive virtual environments is certainly one of them, especially if resources are limited, but not anymore the most critical one. Surprisingly, the different processes used today to generate the walkthroughs experiences take into account very few explicit semantic considerations. The main approaches presented in the literature in the field of LMV are mainly related to algorithms and compression methods to be applied to the geometric entities that compose the CAD model. However, no sufficient attention is given to the following aspects: (i) These models actually belong to a special engineering domain with related standards; (ii) the different potential users have diverse backgrounds and intentions; and (iii) an adapted visualization walkthrough of the model can be different for a specific user and purpose in that context, in order to use in an optimal way the available resources and techniques. Therefore, the most common situation is that the generation of visual walkthrough experiences is typically not aware (in proprietary systems with links to PDM the situation is better to some extent) that the 3D CAD model of a plant is actually just a geometric representation of a complex engineering system, and this knowledge is not sufficiently exploited in the generation of the walkthrough experience. The consequence is to have advanced VR environments for the interactive exploration of models of millions of triangles, that have little explicit use of the knowledge and in many cases none- about the domain, users and visualization purposes involved. As a result, the main motivation for the present work is focused on one of this research lines not sufficiently covered so far: The explicit introduction of semantic aspects, pushed from an engineering domain perspective and strongly complemented with computer graphics and semantic technologies-, in the process of generating visual walkthrough experiences for specific users, visualization purposes and resources in the Plant Design domain.