2,745 research outputs found
Painterly rendering techniques: A state-of-the-art review of current approaches
In this publication we will look at the different methods presented over the past few decades which attempt to recreate digital paintings. While previous surveys concentrate on the broader subject of non-photorealistic rendering, the focus of this paper is firmly placed on painterly rendering techniques. We compare different methods used to produce different output painting styles such as abstract, colour pencil, watercolour, oriental, oil and pastel. Whereas some methods demand a high level of interaction using a skilled artist, others require simple parameters provided by a user with little or no artistic experience. Many methods attempt to provide more automation with the use of varying forms of reference data. This reference data can range from still photographs, video, 3D polygonal meshes or even 3D point clouds. The techniques presented here endeavour to provide tools and styles that are not traditionally available to an artist. Copyright © 2012 John Wiley & Sons, Ltd
Implicit Brushes for Stylized Line-based Rendering
International audienceWe introduce a new technique called Implicit Brushes to render animated 3D scenes with stylized lines in real-time with temporal coherence. An Implicit Brush is defined at a given pixel by the convolution of a brush footprint along a feature skeleton; the skeleton itself is obtained by locating surface features in the pixel neighborhood. Features are identified via image-space ïŹtting techniques that not only extract their location, but also their proïŹle, which permits to distinguish between sharp and smooth features. ProïŹle parameters are then mapped to stylistic parameters such as brush orientation, size or opacity to give rise to a wide range of line-based styles
Posing 3D Models from Drawing
Inferring the 3D pose of a character from a drawing is a complex and under-constrained problem. Solving it may help automate various parts of an animation production pipeline such as pre-visualisation. In this paper, a novel way of inferring the 3D pose from a monocular 2D sketch is proposed. The proposed method does not make any external assumptions about the model, allowing it to be used on different types of characters. The inference of the 3D pose is formulated as an optimisation problem and a parallel variation of the Particle Swarm Optimisation algorithm called PARAC-LOAPSO is utilised for searching the minimum. Testing in isolation as well as part of a larger scene, the presented method is evaluated by posing a lamp, a horse and a human character. The results show that this method is robust, highly scalable and is able to be extended to various types of models
Active Strokes: Coherent Line Stylization for Animated 3D Models
Paper session 8: Lines, strokes and textures in 3DInternational audienceThis paper presents a method for creating coherently animated line drawings that include strong abstraction and stylization effects. These effects are achieved with active strokes: 2D contours that approximate and track the lines of an animated 3D scene. Active strokes perform two functions: they connect and smooth unorganized line samples, and they carry coherent parameterization to support stylized rendering. Line samples are approximated and tracked using active contours ("snakes") that automatically update their arrangment and topology to match the animation. Parameterization is maintained by brush paths that follow the snakes but are independent, permitting substantial shape abstraction without compromising fidelity in tracking. This approach renders complex models in a wide range of styles at interactive rates, making it suitable for applications like games and interactive illustrations
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Spatial navigation, episodic memory, episodic future thinking, and theory of mind in children with autism spectrum disorder: evidence for impairments in mental simulation?
This study explored spatial navigation alongside several other cognitive abilities that are thought to share common underlying neurocognitive mechanisms (e.g., the capacity for self-projection, scene construction, or mental simulation), and which we hypothesized may be impaired in autism spectrum disorder (ASD). Twenty intellectually high-functioning children with ASD (with a mean age of ~8 years) were compared to 20 sex, age, IQ, and language ability matched typically developing children on a series of tasks to assess spatial navigation, episodic memory, episodic future thinking (also known as episodic foresight or prospection), theory of mind (ToM), relational memory, and central coherence. This is the first study to explore these abilities concurrently within the same sample. Spatial navigation was assessed using the âmemory islandâ task, which involves finding objects within a realistic, computer simulated, three-dimensional environment. Episodic memory and episodic future thinking were assessed using a past and future event description task. ToM was assessed using the âanimationsâ task, in which children were asked to describe the interactions between two animated triangles. Relational memory was assessed using a recognition task involving memory for items (line drawings), patterned backgrounds, or combinations of items and backgrounds. Central coherence was assessed by exploring differences in performance across segmented and unsegmented versions of block design. Children with ASD were found to show impairments in spatial navigation, episodic memory, episodic future thinking, and central coherence, but not ToM or relational memory. Among children with ASD, spatial navigation was found to be significantly negatively related to the number of repetitive behaviors. In other words, children who showed more repetitive behaviors showed poorer spatial navigation. The theoretical and practical implications of the results are discussed
Using Computer Simulations as a Pre-Training Activity in a Hands-On Lab to Help Community College Students Improve Their Understanding of Physics
The purpose of this study was to investigate the effectiveness of using computer simulations as a pre-training activity to a hands-on lab to improve studentsâ understanding of induction topics in physics. The computer simulation activity was compared to an overview presentation. Conceptual understanding and spatial ability were measured. A two-group descriptive repeated measures design was implemented with a convenience sample of 35 community college physics students in the Bay Area. Participants were randomly assigned to a simulation group (n = 17) or a presentation group (n = 18). A 30-item spatial ability assessment was given to all participants one week before the day of the experiment.
On the day of the experiment, the simulation group completed a 30-minute induction simulation activity while the presentation group received a 30-minute overview presentation. Both groups then completed a 90-minute hands-on lab. Before completing the simulation activity or receiving the overview presentation, an 18-item conceptual understanding test was given to all participants. The same test was given as a posttest after participants completed the simulation activity or received the overview presentation, and again as a second posttest after participants completed the hands-on lab.
Overall results suggest that the overview presentation was more effective in improving students understanding of induction topics in comparison to completing the simulation activity. However, both groups showed noticeable conceptual understanding gains. The simulations had a medium effect (d = 0.68) and the overview presentation had a large effect (d = 1.07) on conceptual understanding. Results also suggest that high spatial ability participants benefited more from the simulations while the low spatial ability participants benefited more from the overview presentation. Both male and females benefited similarly from the overview presentation. However, male participants seemed to have benefited more from the simulations.
Although the overview presentation was more effective in improving students understanding of induction topics, the 30-minute computer simulation activity still made a difference in student learning. This result can be seen as a positive finding suggesting that 30-minutes of working with simulations could help students improve their understanding of physics concepts even if they had not used the simulations before
MARS: a tool-based modeling, animation and parallel rendering system
Ankara : Department of Computer Engineering and Information Science and Institute of Engineering and Science, Bilkent Univ., 1992.Thesis (Master's) -- Bilkent University, 1992.Includes bibliographical refences.A b stract: This thesis describes a system for modeling, animating, previewing
and rendering articulated objects. Tl^^ system has a modeler which models objects,
consisting of joints and segments. The animatoi- interactively positions the articulated
object in its stick, control vertex or rectangular prism representation into the
keyframes, interpolates inbetweens and previews the motion in real time. Then the
data representing the motion and the models is sent to a multicomputer {iPSC/2
Ilypercube^). The frames are rendered in parallel by distributed processing techniques,
exploiting the coherence between successive frames, thus cutting down the
rendering time significantly. The main aim of this research has been to make a detailed
study on rendering of a sequence of 3D scenes. The results show that due to
an inherent correlation between the 3D scenes, a much more efficient rendering than
the conventional sequential one can be done.AktıhanoÄlu, MuratM.S
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