K. Henriksen - Academia.edu (original) (raw)

Papers by K. Henriksen

Research paper thumbnail of Feature-Based Stereo Matching

Research paper thumbnail of Scripted motion and spline driven motion

Research paper thumbnail of Trackballs Revisited

Research paper thumbnail of Physics-based animation

Competencias genéricas Saber aplicar técnicas de simulación física para resolver problemas de ani... more Competencias genéricas Saber aplicar técnicas de simulación física para resolver problemas de animación gráfica (efectos especiales, simulación en vídeo juegos, realidad virtual…) Competencias específicas Dominar los elementos de una simulación, desde las leyes físicas que ...

Research paper thumbnail of B-splines

Research paper thumbnail of Direct determination of the orientation of a translating 3D straight line

Pattern Recognition Letters, 1989

Abstract A new method for determination of spatial orientation of a straight line is derived. The... more Abstract A new method for determination of spatial orientation of a straight line is derived. The system is linear and involve orientation of the projected line and optic flow of one feature point, but neither camera position nor motion.

Research paper thumbnail of Computing the Time-Varying Orientation of a Moving 3D Straight Line

Research paper thumbnail of Using mirror caneras for estimating depth

Research paper thumbnail of Direct Dtermination of the Orientation of a 3-D Translating Straight Line

Research paper thumbnail of Direct Dtermination of the Orientation of a 3-D Translating Straight Line

Research paper thumbnail of Stereo ranging with verging cameras

IEEE Transactions on Pattern Analysis and Machine Intelligence, 1990

Absfract-We present a novel method to compute absolute range from stereo disparities with verging... more Absfract-We present a novel method to compute absolute range from stereo disparities with verging cameras. The approach differs from others by concentrating, through both analysis and experiment, on the effects caused by convergence, rather than on the general camera calibration problem. To compute stereo disparities we first extract linear image features and then match them using a hypothesize-and-verify method. To compute range we derive the relationship between object distance, vergence angle, and disparity. Experimental results show the precision of the range computation, excluding mistaken matches, to be approximately 5% for object distances up to three meters and a baseline distance of 13 cm. Including mistaken matches results in performance an order of magnitude worse, leading us to suggest methods to identify and model them.

Research paper thumbnail of Virtual trackballs revisited

IEEE Transactions on Visualization and Computer Graphics, 2004

Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-ai... more Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [1]. We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual trackball and we give a correction. Another popular virtual trackball is Shoemake's quaternion implementation [2], which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake's virtual trackball is inhomogeneous and discontinuous with consequences for usability. Finally, we review Bell's virtual trackball [3] and discuss studies of the usability of virtual trackballs.

Research paper thumbnail of Virtual trackballs revisited

Abstract—Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in co... more Abstract—Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [1]. We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual trackball and we give a correction. Another popular virtual trackball is Shoemake’s quaternion implementation [2], which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake’s virtual trackball is inhomogeneous and discontinuous with consequences for usability. Finally, we review Bell’s virtual...

Research paper thumbnail of A Simple Plane Patcher Algorithm

The daily work with mesh data structures can be a painful experience. Topological inconsistency a... more The daily work with mesh data structures can be a painful experience. Topological inconsistency and digital mockup is part of daily life and often unwanted in both visualization, collision detection and animation. In this paper we focus on the particular problem of patching (also termed capping) an open boundary of a mesh after it has been cut by a plane. The paper describes an algorithm for planar patching and outlines an implementation. The novel contribution is a divide and conquer algorithm working on a spatial hierarchical data structure of the cutting boundaries of the mesh.

Research paper thumbnail of Scripted bodies and spline-driven animation

In this paper we will take a close look at the details and technicalities in applying spline driv... more In this paper we will take a close look at the details and technicalities in applying spline driven animation to scripted bodies in the context of dynamic simulation. The main contributions presented in this paper are methods for computing velocities and accelerations in the time domain of the space splines.

Research paper thumbnail of Physics Based Animation (Graphics Series)

Research paper thumbnail of A Simple Plane Patcher Algorithm

The daily work with mesh data structures can be a painful experience. Topological inconsistency a... more The daily work with mesh data structures can be a painful experience. Topological inconsistency and digital mockup is part of daily life and often unwanted in both visualization, collision detection and animation. In this paper we focus on the particular problem of patching (also termed capping) an open boundary of a mesh after it has been cut by a plane. The paper describes an algorithm for planar patching and outlines an implementation. The novel contribution is a divide and conquer algorithm working on a spatial hierarchical data structure of the cutting boundaries of the mesh.

Research paper thumbnail of A Simple Plane Patcher Algorithm

The daily work with mesh data structures can be a painful expe rience. Topological inconsistency ... more The daily work with mesh data structures can be a painful expe rience. Topological inconsistency and digital mockup is part of daily life and often unwanted in both visualization, collision de tection and animation. In this paper we focus on the particular problem of patching ( also termed capping) an open boundary of a mesh after it has been cu t by a plane. The paper describes an algorithm for planar patchin g and outlines an implementation. The novel contribution is a div ide and conquer algorithm working on a spatial hierarchical data st ructure of the cutting boundaries of the mesh. CR Categories: I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling—Boundary representations; I .3.5 [Computer Graphics]: Computational Geometry and Object Modeling—Constructive solid geometry (CSG);

Research paper thumbnail of В-Splines

Research paper thumbnail of Relating Scene Depth to Image Ratios

Lecture Notes in Computer Science, 1999

... If the base line between the optic centers of the cameras has length ∆ then the lens planes a... more ... If the base line between the optic centers of the cameras has length ∆ then the lens planes are separated by the amount δ = ∆ sin β. The resulting composite image for a binocular side view of two scene points P1 and P2 with different and finite depths is shown in figure 4 If the ...

Research paper thumbnail of Feature-Based Stereo Matching

Research paper thumbnail of Scripted motion and spline driven motion

Research paper thumbnail of Trackballs Revisited

Research paper thumbnail of Physics-based animation

Competencias genéricas Saber aplicar técnicas de simulación física para resolver problemas de ani... more Competencias genéricas Saber aplicar técnicas de simulación física para resolver problemas de animación gráfica (efectos especiales, simulación en vídeo juegos, realidad virtual…) Competencias específicas Dominar los elementos de una simulación, desde las leyes físicas que ...

Research paper thumbnail of B-splines

Research paper thumbnail of Direct determination of the orientation of a translating 3D straight line

Pattern Recognition Letters, 1989

Abstract A new method for determination of spatial orientation of a straight line is derived. The... more Abstract A new method for determination of spatial orientation of a straight line is derived. The system is linear and involve orientation of the projected line and optic flow of one feature point, but neither camera position nor motion.

Research paper thumbnail of Computing the Time-Varying Orientation of a Moving 3D Straight Line

Research paper thumbnail of Using mirror caneras for estimating depth

Research paper thumbnail of Direct Dtermination of the Orientation of a 3-D Translating Straight Line

Research paper thumbnail of Direct Dtermination of the Orientation of a 3-D Translating Straight Line

Research paper thumbnail of Stereo ranging with verging cameras

IEEE Transactions on Pattern Analysis and Machine Intelligence, 1990

Absfract-We present a novel method to compute absolute range from stereo disparities with verging... more Absfract-We present a novel method to compute absolute range from stereo disparities with verging cameras. The approach differs from others by concentrating, through both analysis and experiment, on the effects caused by convergence, rather than on the general camera calibration problem. To compute stereo disparities we first extract linear image features and then match them using a hypothesize-and-verify method. To compute range we derive the relationship between object distance, vergence angle, and disparity. Experimental results show the precision of the range computation, excluding mistaken matches, to be approximately 5% for object distances up to three meters and a baseline distance of 13 cm. Including mistaken matches results in performance an order of magnitude worse, leading us to suggest methods to identify and model them.

Research paper thumbnail of Virtual trackballs revisited

IEEE Transactions on Visualization and Computer Graphics, 2004

Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-ai... more Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [1]. We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual trackball and we give a correction. Another popular virtual trackball is Shoemake's quaternion implementation [2], which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake's virtual trackball is inhomogeneous and discontinuous with consequences for usability. Finally, we review Bell's virtual trackball [3] and discuss studies of the usability of virtual trackballs.

Research paper thumbnail of Virtual trackballs revisited

Abstract—Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in co... more Abstract—Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [1]. We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual trackball and we give a correction. Another popular virtual trackball is Shoemake’s quaternion implementation [2], which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake’s virtual trackball is inhomogeneous and discontinuous with consequences for usability. Finally, we review Bell’s virtual...

Research paper thumbnail of A Simple Plane Patcher Algorithm

The daily work with mesh data structures can be a painful experience. Topological inconsistency a... more The daily work with mesh data structures can be a painful experience. Topological inconsistency and digital mockup is part of daily life and often unwanted in both visualization, collision detection and animation. In this paper we focus on the particular problem of patching (also termed capping) an open boundary of a mesh after it has been cut by a plane. The paper describes an algorithm for planar patching and outlines an implementation. The novel contribution is a divide and conquer algorithm working on a spatial hierarchical data structure of the cutting boundaries of the mesh.

Research paper thumbnail of Scripted bodies and spline-driven animation

In this paper we will take a close look at the details and technicalities in applying spline driv... more In this paper we will take a close look at the details and technicalities in applying spline driven animation to scripted bodies in the context of dynamic simulation. The main contributions presented in this paper are methods for computing velocities and accelerations in the time domain of the space splines.

Research paper thumbnail of Physics Based Animation (Graphics Series)

Research paper thumbnail of A Simple Plane Patcher Algorithm

The daily work with mesh data structures can be a painful experience. Topological inconsistency a... more The daily work with mesh data structures can be a painful experience. Topological inconsistency and digital mockup is part of daily life and often unwanted in both visualization, collision detection and animation. In this paper we focus on the particular problem of patching (also termed capping) an open boundary of a mesh after it has been cut by a plane. The paper describes an algorithm for planar patching and outlines an implementation. The novel contribution is a divide and conquer algorithm working on a spatial hierarchical data structure of the cutting boundaries of the mesh.

Research paper thumbnail of A Simple Plane Patcher Algorithm

The daily work with mesh data structures can be a painful expe rience. Topological inconsistency ... more The daily work with mesh data structures can be a painful expe rience. Topological inconsistency and digital mockup is part of daily life and often unwanted in both visualization, collision de tection and animation. In this paper we focus on the particular problem of patching ( also termed capping) an open boundary of a mesh after it has been cu t by a plane. The paper describes an algorithm for planar patchin g and outlines an implementation. The novel contribution is a div ide and conquer algorithm working on a spatial hierarchical data st ructure of the cutting boundaries of the mesh. CR Categories: I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling—Boundary representations; I .3.5 [Computer Graphics]: Computational Geometry and Object Modeling—Constructive solid geometry (CSG);

Research paper thumbnail of В-Splines

Research paper thumbnail of Relating Scene Depth to Image Ratios

Lecture Notes in Computer Science, 1999

... If the base line between the optic centers of the cameras has length ∆ then the lens planes a... more ... If the base line between the optic centers of the cameras has length ∆ then the lens planes are separated by the amount δ = ∆ sin β. The resulting composite image for a binocular side view of two scene points P1 and P2 with different and finite depths is shown in figure 4 If the ...