Article

Técnicas de interacción y campo de trabajo en la selección de objetos en Realidad Virtual

ABSTRACT
Resumen. Este trabajo describe un estudio experimental sobre los efectos del campo de trabajo y la técnica de interacción en la selección de objetos. En concreto, se pretende analizar sus efectos sobre la eficiencia y precisión en la tarea de selección restringida en tiempo de objetos situados a diferentes distancias. Los resultados obtenidos muestran que el campo de trabajo puede determinar cuál es la técnica de interacción más precisa y que las técnicas basadas en ray-casting ofrecen mejores prestaciones que las basadas en mano virtual. 1 Introducción Los sistemas de realidad virtual conforman un paradigma que todavía puede considerarse innovador en la interacción persona-ordenador. Son muchos los estudios realizados sobre las ventajas y desventajas de los entornos virtuales inmersivos en ámbitos de diferente índole: tratamiento psicológico, diseño, visualización, adiestramiento médico y militar etc. Si bien los resultados de estos estudios resultan esperanzadores, la interacción tridimensional sigue siendo en muchos casos un problema no resuelto. La interacción en un mundo virtual se puede desglosar en dos mecanismos principalmente: navegación [1] y selección/manipulación [2]. Nuestro trabajo está dedicado a las técnicas de selección. Con el paso del tiempo se han propuesto diversos mecanismos de selección que van más allá de la metáfora natural; ejemplos de estos mecanismos son la utilización de secciones volumétricas selectoras a modo de cursores 3D (trasladando el concepto del ratón al espacio tridimensional) [3], escalado relativo del usuario respecto al mundo [5], selección sobre miniaturizaciones del entorno virtual [4], selección por apertura [6], mano virtual Go-Go [2], etc. La mayoría de estas técnicas de selección pueden clasificarse en dos grupos: selección con mano virtual, y selección con rayo o ray-casting [7]. Nuestro trabajo pretende comparar un pequeño grupo de éstas técnicas en un entorno con objetos de tamaño y posición variables. Nuestra hipótesis es que la eficiciencia en las tareas de selección, no sólo dependerá de la técnica usada, sino que otras variables, como las dimensiones del campo de trabajo pueden interactuar con la técnica usada. Dicho de otro modo, la mejor técnica para campos de trabajo pequeños no tiene por qué ser también la mejor en campos grandes.

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