16 International Journal of Creative Interfaces and Computer Graphics, 3(1), 16-27, January-June 2012 Copyright © 2012, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Copyright © 2012, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Keywords: Collision Detection, Computer Science,GPU, Graphics Computing, Image Space,Multitexturing, Texture Space INTRODUCTION Collision detection is a well known problem in computer graphics, with applications in sev- eral fields including animation, virtual reality, video games and simulation. The possibility of representing volumes and surfaces in the same scene is a consequence of the current popularity of graphics hardware supporting 3D texturing. Virtual surgery, medical planning and volume edition are only a few examples of applications requiring the interaction of volumetric datasets with virtual objects represented commonly by polygonal meshes. Currently a virtual surgery room is being developed at Universidad Central de Venezuela, with the goal of simulating knee surgeries. This kind of application requires mixed data because the bones and muscles are volumetric data from CT scans, while the surgical instruments are represented as meshes. This imposes the need for special collision detection techniques that can handle the interactions between volumes and meshes. Besides this, different parts of the An Image-Space Approach for Collision Detection Between Multiple Volumes and a Surface Rhadamés Carmona, Universidad Central de Venezuela, Venezuela Héctor Navarro, Universidad Central de Venezuela, Venezuela ABSTRACT Collision detection has been studied for scenes containing only polygonal objects (surfaces) or only volumes. With the evolution of the graphics hardware, surfaces and volumes can be rendered together, demanding new challenges for the area of collision detection. In this order of ideas, the authors propose the frst approach for volume-surface collision detection, with GPU support. A mapping from surface space to texture space is established, such as each mesh fragment has a 3D texture coordinate. The volume-surface collision is tested in the fragment shader, verifying if a surface fragment is texturized with an opaque voxel. OpenGL® occlusion query extension is used to count the number of mesh fragments colliding with the volume. Since one surface can be texturized with multiple volume textures, the authors’approach is naturally extended to discard collision between one surface and several volumes in a single pass, with a minimum impact in the rendering time. The authors’ tests reveal that collision between thousands of volume-mesh pairs can be evaluated in one second, showing that our solution is ideal for real-time applications. DOI: 10.4018/jcicg.2012010102