Tianchen Xu | University of Macau (original) (raw)
Papers by Tianchen Xu
IEEE Transactions on Visualization and Computer Graphics
This paper presents a novel approach for generating the real-time fluid flow driven by the motion... more This paper presents a novel approach for generating the real-time fluid flow driven by the motion of the character in full 3D space, based on Smoothed-Particle Hydrodynamics method. In the past relevant works, the real-time fluid-character animation could hardly be achieved due to the intensive processing demand on the movement of the character and fluid simulation. In order to handle such interactions, the motion trajectory of the character is first estimated, and then the movement of particles is constrained by the geometric properties of the trajectory. Furthermore, the efficient algorithms of the particle searching and rendering are proposed, by taking advantage of the GPU parallelization. Consequently, both simulation and rendering of 3D liquid effects with realistic character interaction can be performed on a conventional PC in real-time.
Computer Animation and Virtual Worlds, 2020
Generally, it is regarded as challenge work to grasp the drawing style of an ancient masterpiece ... more Generally, it is regarded as challenge work to grasp the drawing style of an ancient masterpiece in Chinese painting learning. This paper presents a novel approach to the generation of a Chinese ink painting in a certain style and animating its brushwork process with expert skills. In order to demonstrate the techniques of brush and ink inside a stroke, a serials of geometric properties of a brush stroke, are first extracted, then through rational deformation calculation, the best stroke source is mapped onto the stroking path, which is sketched by the user, and finally a new Chinese painting can be synthesized by style migration and natural stroke composition. So with the generated strokes, the lifelike brushwork process of the new painting can be represented dramatically. Actually, by showing the authentic painting process, the tool we implemented helps the learners, who have no profound skills and knowledge in domain of Chinese painting, master the essence of a great painting style, and also provides an easy way to art creation and the comprehension of mysterious Chinese traditional art.
2018 IEEE International Conference on Applied System Invention (ICASI), 2018
The easy acquisition of various information of a Chinese calligraphic character can greatly enhan... more The easy acquisition of various information of a Chinese calligraphic character can greatly enhance comprehension and learning efficiency of Chinese calligraphy. This paper presents a handy tool for fast searching all kinds of information of a written calligraphic character. Taking the characters written in regular style for example, which are the popular and representative style in calligraphy, first we establish an information library of over 6,700 standard Chinese calligraphy including Pinyin, structure, components and explanation. Then in order to fast identify a given image of a written calligraphic character in the library, we build a neural network with a feature set that largely determines the shape and spatial structure of a character and for the character that is provided more than one identifying results, we turn to image-based matching algorithm to find out the one with the highest similarity. Finally, users can easily obtain the whole information of the input character.
SIGGRAPH Asia 2019 Technical Briefs on - SA '19, 2019
This paper presents a novel solution for approximations to some large convolution kernels by leve... more This paper presents a novel solution for approximations to some large convolution kernels by leveraging a weighted box-filtered image pyramid set. Convolution filters are widely used, but still compute-intensive for real-time rendering when the kernel size is large. Our algorithm approximates the convolution kernels, such as Gaussian and cosine filters, by two phases of down and up sampling on a GPU. The computational complexity only depends on the input image resolution and is independent of the kernel size. Therefore, our method can be applied to nonuniform blurs, irradiance probe generations, and ray-traced glossy global illuminations in real time, and runs in effective and efficient performance.
SIGGRAPH ASIA 2016 Technical Briefs, 2016
This paper presents a novel approach to fast rendering realistic meta-balls in view space. Meta-b... more This paper presents a novel approach to fast rendering realistic meta-balls in view space. Meta-ball rendering is widely used in computer graphics to represent liquid drops, and especially important to particle-based fluid dynamics for the rendering on the final stage. Traditionally, meta-balls are procedurally modeled in object space according to implicit surface extraction and rendered as meshes. Instead of such consuming geometry-based methods, our algorithm is executed at screen-space level, and it utilizes the features of GPU, which demands low overheads and thus is much faster. Compared with other screen-space methods of particle rendering, our method obeys the basic principle of implicit surface. Consequently, real-time meta-ball rendering can be achieved very efficiently in a significantly high quality.
International Journal of Virtual Reality, 2011
With regard to skeletal character animation, the question on how to ensure the quality of transit... more With regard to skeletal character animation, the question on how to ensure the quality of transition between key frames is of crucial importance. The lack of properly defined motion ranges based on movements would leave the animator with no choice but intervene the result based on camera perspective afterwards, thus creating a lot more work for the animator to modify or clean up the animation curves. Although a number of methods have been raised in these years, such as the Linear Blending Skinning (LBS), they may still have shortcomings in some specific cases, one of which is the obvious unnatural deformation around the joint areas. The primary investigation in this paper is directed to address the problem and improve the framework of rendering in real-time environment with satisfactory skinning effect to the aforementioned scenario, with assistance of GPU computation
SIGGRAPH Asia 2014 Technical Briefs, 2014
ABSTRACT
Science China Information Sciences, 2016
Transactions on Edutainment XI, 2015
We propose an interactive construction method of 3D objects from Chinese ink paintings for the ch... more We propose an interactive construction method of 3D objects from Chinese ink paintings for the challenge problem of generating the Chinese ink animation. Marching Cube method is the popular method of 3D modeling; however, it has the limitation on constructing the objects with complex shapes by lines in Chinese ink paintings. Based on our method, we develop a software system for constructing 3D objects interactively by the manual input of brush strokes from the Chinese ink paintings. And then the system can generate 3D objects with 2D surface mesh and 3D skinned mesh automatically. Finally, the system renders them with the original ink effect textures of input image. Our experiments show that the approach is suitable for converting 2D painting image into 3D objects. This work would be helpful for the problem of generating 3D animation of Chinese ink painting.
Proceedings of the 10th International Conference on Virtual Reality Continuum and Its Applications in Industry - VRCAI '11, 2011
SIGGRAPH Asia 2012 Technical Briefs on - SA '12, 2012
ABSTRACT This paper presents a novel approach for real-time ink wash painting style rendering on ... more ABSTRACT This paper presents a novel approach for real-time ink wash painting style rendering on geometric models. We first create an ink footprint model in particle form, then extract classified strokes from ordinary 3D models by utilizing the existing geometry information, and finally combine the strokes and the ink to generate an immersive painted image. By taking advantage of parallel processing on GPU, consequently, the rendering of geometric models with realistic features of Chinese ink painting can be performed on a consumer-level PC in real-time.
Science China Information Sciences, 2012
Computer Animation and Virtual Worlds, 2013
SIGGRAPH Asia 2021 Technical Communications, 2021
SIGGRAPH Asia 2019 Technical Briefs, Nov 17, 2019
This paper presents a novel solution for approximations to some large convolution kernels by leve... more This paper presents a novel solution for approximations to some large convolution kernels by leveraging a weighted box-filtered image pyramid set. Convolution filters are widely used, but still compute-intensive for real-time rendering when the kernel size is large. Our algorithm approximates the convolution kernels, such as Gaussian and cosine filters, by two phases of down and up sampling on a GPU. The computational complexity only depends on the input image resolution and is independent of the kernel size. Therefore, our method can be applied to nonuniform blurs, irradiance probe generations, and ray-traced glossy global illuminations in real time, and runs in effective and efficient performance.
IEEE Transactions on Visualization and Computer Graphics
This paper presents a novel approach for generating the real-time fluid flow driven by the motion... more This paper presents a novel approach for generating the real-time fluid flow driven by the motion of the character in full 3D space, based on Smoothed-Particle Hydrodynamics method. In the past relevant works, the real-time fluid-character animation could hardly be achieved due to the intensive processing demand on the movement of the character and fluid simulation. In order to handle such interactions, the motion trajectory of the character is first estimated, and then the movement of particles is constrained by the geometric properties of the trajectory. Furthermore, the efficient algorithms of the particle searching and rendering are proposed, by taking advantage of the GPU parallelization. Consequently, both simulation and rendering of 3D liquid effects with realistic character interaction can be performed on a conventional PC in real-time.
Computer Animation and Virtual Worlds, 2020
Generally, it is regarded as challenge work to grasp the drawing style of an ancient masterpiece ... more Generally, it is regarded as challenge work to grasp the drawing style of an ancient masterpiece in Chinese painting learning. This paper presents a novel approach to the generation of a Chinese ink painting in a certain style and animating its brushwork process with expert skills. In order to demonstrate the techniques of brush and ink inside a stroke, a serials of geometric properties of a brush stroke, are first extracted, then through rational deformation calculation, the best stroke source is mapped onto the stroking path, which is sketched by the user, and finally a new Chinese painting can be synthesized by style migration and natural stroke composition. So with the generated strokes, the lifelike brushwork process of the new painting can be represented dramatically. Actually, by showing the authentic painting process, the tool we implemented helps the learners, who have no profound skills and knowledge in domain of Chinese painting, master the essence of a great painting style, and also provides an easy way to art creation and the comprehension of mysterious Chinese traditional art.
2018 IEEE International Conference on Applied System Invention (ICASI), 2018
The easy acquisition of various information of a Chinese calligraphic character can greatly enhan... more The easy acquisition of various information of a Chinese calligraphic character can greatly enhance comprehension and learning efficiency of Chinese calligraphy. This paper presents a handy tool for fast searching all kinds of information of a written calligraphic character. Taking the characters written in regular style for example, which are the popular and representative style in calligraphy, first we establish an information library of over 6,700 standard Chinese calligraphy including Pinyin, structure, components and explanation. Then in order to fast identify a given image of a written calligraphic character in the library, we build a neural network with a feature set that largely determines the shape and spatial structure of a character and for the character that is provided more than one identifying results, we turn to image-based matching algorithm to find out the one with the highest similarity. Finally, users can easily obtain the whole information of the input character.
SIGGRAPH Asia 2019 Technical Briefs on - SA '19, 2019
This paper presents a novel solution for approximations to some large convolution kernels by leve... more This paper presents a novel solution for approximations to some large convolution kernels by leveraging a weighted box-filtered image pyramid set. Convolution filters are widely used, but still compute-intensive for real-time rendering when the kernel size is large. Our algorithm approximates the convolution kernels, such as Gaussian and cosine filters, by two phases of down and up sampling on a GPU. The computational complexity only depends on the input image resolution and is independent of the kernel size. Therefore, our method can be applied to nonuniform blurs, irradiance probe generations, and ray-traced glossy global illuminations in real time, and runs in effective and efficient performance.
SIGGRAPH ASIA 2016 Technical Briefs, 2016
This paper presents a novel approach to fast rendering realistic meta-balls in view space. Meta-b... more This paper presents a novel approach to fast rendering realistic meta-balls in view space. Meta-ball rendering is widely used in computer graphics to represent liquid drops, and especially important to particle-based fluid dynamics for the rendering on the final stage. Traditionally, meta-balls are procedurally modeled in object space according to implicit surface extraction and rendered as meshes. Instead of such consuming geometry-based methods, our algorithm is executed at screen-space level, and it utilizes the features of GPU, which demands low overheads and thus is much faster. Compared with other screen-space methods of particle rendering, our method obeys the basic principle of implicit surface. Consequently, real-time meta-ball rendering can be achieved very efficiently in a significantly high quality.
International Journal of Virtual Reality, 2011
With regard to skeletal character animation, the question on how to ensure the quality of transit... more With regard to skeletal character animation, the question on how to ensure the quality of transition between key frames is of crucial importance. The lack of properly defined motion ranges based on movements would leave the animator with no choice but intervene the result based on camera perspective afterwards, thus creating a lot more work for the animator to modify or clean up the animation curves. Although a number of methods have been raised in these years, such as the Linear Blending Skinning (LBS), they may still have shortcomings in some specific cases, one of which is the obvious unnatural deformation around the joint areas. The primary investigation in this paper is directed to address the problem and improve the framework of rendering in real-time environment with satisfactory skinning effect to the aforementioned scenario, with assistance of GPU computation
SIGGRAPH Asia 2014 Technical Briefs, 2014
ABSTRACT
Science China Information Sciences, 2016
Transactions on Edutainment XI, 2015
We propose an interactive construction method of 3D objects from Chinese ink paintings for the ch... more We propose an interactive construction method of 3D objects from Chinese ink paintings for the challenge problem of generating the Chinese ink animation. Marching Cube method is the popular method of 3D modeling; however, it has the limitation on constructing the objects with complex shapes by lines in Chinese ink paintings. Based on our method, we develop a software system for constructing 3D objects interactively by the manual input of brush strokes from the Chinese ink paintings. And then the system can generate 3D objects with 2D surface mesh and 3D skinned mesh automatically. Finally, the system renders them with the original ink effect textures of input image. Our experiments show that the approach is suitable for converting 2D painting image into 3D objects. This work would be helpful for the problem of generating 3D animation of Chinese ink painting.
Proceedings of the 10th International Conference on Virtual Reality Continuum and Its Applications in Industry - VRCAI '11, 2011
SIGGRAPH Asia 2012 Technical Briefs on - SA '12, 2012
ABSTRACT This paper presents a novel approach for real-time ink wash painting style rendering on ... more ABSTRACT This paper presents a novel approach for real-time ink wash painting style rendering on geometric models. We first create an ink footprint model in particle form, then extract classified strokes from ordinary 3D models by utilizing the existing geometry information, and finally combine the strokes and the ink to generate an immersive painted image. By taking advantage of parallel processing on GPU, consequently, the rendering of geometric models with realistic features of Chinese ink painting can be performed on a consumer-level PC in real-time.
Science China Information Sciences, 2012
Computer Animation and Virtual Worlds, 2013
SIGGRAPH Asia 2021 Technical Communications, 2021
SIGGRAPH Asia 2019 Technical Briefs, Nov 17, 2019
This paper presents a novel solution for approximations to some large convolution kernels by leve... more This paper presents a novel solution for approximations to some large convolution kernels by leveraging a weighted box-filtered image pyramid set. Convolution filters are widely used, but still compute-intensive for real-time rendering when the kernel size is large. Our algorithm approximates the convolution kernels, such as Gaussian and cosine filters, by two phases of down and up sampling on a GPU. The computational complexity only depends on the input image resolution and is independent of the kernel size. Therefore, our method can be applied to nonuniform blurs, irradiance probe generations, and ray-traced glossy global illuminations in real time, and runs in effective and efficient performance.
SIGGRAPH Asia 2019 Technical Briefs
SIGGRAPH Asia 2016 Technical Briefs
SIGGRAPH Asia 2014 Technical Briefs
SIGGRAPH Asia 2012 Technical Briefs
Proceedings of Computer Animation and Social Agents 2013
Proceedings of the 10th International Conference on Virtual Reality Continuum and Its Applications in Industry
Nowadays, computers play a significant role in art creation as new media and tools. Hence, the re... more Nowadays, computers play a significant role in art creation as new media and tools. Hence, the relevant techniques on non-photorealistic animation and rendering, artistic simulation, and computational aesthetics are demanding to satisfy the expectation of the digital artists and attract the eyes of the beholders. This thesis presents the main research works finished during the author’s Master studying, which focus on artistic simulation and rendering, as well as two useful novel techniques for ink-wash stylistic rendering and artistic special effects based on fluid simulation.
In our first research work, a novel approach to real-time ink-wash stylistic rendering from 3D geometric models is proposed. Firstly, the strokes are classified and extracted from ordinary 3D models by utilizing the existing geometry information, and finally a lifelike painted image can be generated by combining the stroke properties and our ink model. By taking advantage of parallel processing on GPU, the rendering of geometric models with realistic features of Chinese ink painting can be consequently performed on a consumer-level PC in real-time.
Moreover, our second work proposes a physically based simulation-rendering framework to generate vivid character-driven special effects that enhance the artistic visual perception of 3D animations. The complex interactions between the liquid simulation based on SPH and deformable character are successfully handled by taking advantage the general-purpose GPU computing. Furthermore, an optimized neighbor search and an improved screen-space particle rendering are also proposed in our framework. As a result, both of the fluid simulation and liquid rendering with realistic illumination can be realized in real-time by using our method.
Moreover, our second work proposes a physically based simulation-rendering framework to generate ... more Moreover, our second work proposes a physically based simulation-rendering framework to generate vivid character-driven special effects that enhance the artistic visual perception of 3D animations. The complex interactions between the liquid simulation based on SPH and deformable character are successfully handled by taking advantage the general-purpose GPU computing. Furthermore, an optimized neighbor search and an improved screen-space particle rendering are also proposed in our framework. As a result, both of the fluid simulation and liquid rendering with realistic illumination can be realized in real-time by using our method.