328 research outputs found
3D computational steering with parametrized geometric objects
Computational Steering is the ultimate goal of interactive simulation: researchers change parameters of their simulation and immediately receive feedback on the effect. We present a general and flexible graphics tool that is part of an environment for Computational Steering developed at CWI. It enables the researcher to interactively develop his own interface with the simulation. This interface is constructed with 3D Parametrized Geometric Objects. The properties of the objects are parametrized to output data and input parameters of the simulation. The objects visualize the output of the simulation while the researcher can steer the simulation by direct manipulation of the objects. Several applications of 3D Computational Steering are presented
Parametrizable cameras for 3D computational steering
We present a method for the definition of multiple views in 3D interfaces for computational steering. The method uses the concept of a point-based parametrizable camera object. This concept enables a user to create and configure multiple views on his custom 3D interface in an intuitive graphical manner. Each view can be coupled to objects present in the interface, parametrized to (simulation) data, or adjusted through direct manipulation or user defined camera controls. Although our focus is on 3D interfaces for computational steering, we think that the concept is valuable for many other 3D graphics applications as well
Logging in a computational steering environment
Logging of input and output variables is very useful in computational steering. In this paper we describe how we added logging functionality to a computational steering environment developed at CWI. We show how a 2D interface can be augmented with logging by using the third dimension for the display of the logged variables. The user specifies which graphical representations of variables must be logged, and this log is displayed together with the current state of the simulation. Two examples show that logging in computational steering gives more insight in the simulation, that it can be used for monitoring, and that it can be used to undo erroneous actions
Pixel masks for screen-door transparency
Rendering objects transparently gives additional insight in complex and overlapping structures. However, traditional techniques for the rendering of transparent objects such as alpha blending are not very well suited for the rendering of multiple transparent objects in dynamic scenes. Screen-door transparency is a technique to render transparent objects in a simple and efficient way: No sorting is required and intersecting polygons can be handled without further preprocessing. With this technique, polygons are rendered through a mask: Only where the mask is present, pixels are set. However, artifacts such as incorrect opacities and distracting patterns can easily occur if the masks are not carefully designed. In this paper, first the requirements on the masks are considered. Next, three algorithms are presented for the generation of pixel masks. One algorithm is designed for the creation of small (e.g. 4 4) masks. The other two algorithms can be used for the creation of larger masks (e.g. 32 32). For each of these algorithms results are presented and discussed
Virtual Reality and Desktop as a Combined Interaction-Visualisation Medium for a Problem-Solving Environment
Computational steering
The traditional cycle in simulation is to prepare input, execute a simulation, and to visualize the results as a post-processing step. However, more insight and a higher productivity can be achieved if these activities are done simultaneously. This is the underlying idea of Computational Steering: researchers change parameters of their simulation on the fly and immediately receive feedback on the effect. In this paper the Computational Steering Environment, CSE, developed at CWI is described. We discuss the requirements of computational steering environment, its relation with high performance computing and networking, and show an application of its use
Bringing computational steering to the user
Computational steering is a technique that combines simulation and visualization. The user is continuously provided with visual feedback about the state of the simulation, and can change parameters on the fly. Designers can vary parameters to optimize their product, users can detect errors in the input early, researchers can do qualitative sensitivity analyses easily. The implementation of computational steering is very tedious. It requires knowledge of the simulation, visualization, user interfacing, and data communication. In this paper we discuss an environment that enables users to implement and use computational steering effectively without much support from user interface experts. We show how the environment is applied to various applications
Direct Ink Writing of Recyclable Supramolecular Soft Actuators
Direct ink writing (DIW) of liquid crystal elastomers (LCEs) has rapidly paved its way into the field of soft actuators and other stimuli-responsive devices. However, currently used LCE systems for DIW require postprinting (photo)polymerization, thereby forming a covalent network, making the process time-consuming and the material nonrecyclable. In this work, a DIW approach is developed for printing a supramolecular poly(thio)urethane LCE to overcome these drawbacks of permanent cross-linking. The thermo-reversible nature of the supramolecular cross-links enables the interplay between melt-processable behavior required for extrusion and formation of the network to fix the alignment. After printing, the actuators demonstrated a reversible contraction of 12.7% or bending and curling motions when printed on a passive substrate. The thermoplastic ink enables recyclability, as shown by cutting and printing the actuators five times. However, the actuation performance diminishes. This work highlights the potential of supramolecular LCE inks for DIW soft circular actuators and other devices
Computational steering in the CAVE
Scientists can gain much more insight from their simulations if they are enabled to change simulation parameters on the fly while observing the results immediately. A crucial aspect of such {em computational steering/ is an intuitive user interface. We have developed an environment that enables researchers to construct such interfaces efficiently and effectively for graphical workstations. In this paper we report on our next step towards more intuitive user-interfaces: We have modified our system for use in the CAVE. The CAVE is a projection-based virtual environment. Virtual environments are designed to provide the effect of immersion in an interactive three-dimensional computer-generated environment. We show that the use of virtual environments for computational steering interfaces can improve interaction with the simulation and immersion in the computational process. We present our system, the methods we have developed for improved 3D interaction, and describe three applications
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