Abstract: An interactive palette interface includes a color picker for digital paint applications. A user can create, modify and select colors for creating digital artwork using the interactive palette interface. The interactive palette interface includes a mixing dish in which colors can be added, removed and rearranged to blend together to create gradients and gamuts. The mixing dish is a digital simulation of a physical palette on which an artist adds and mixes various colors of paint before applying the paint to the artwork. Color blobs, which are logical groups of pixels in the mixing dish, can be spatially rearranged and scaled by a user to create and explore different combinations of colors. The color, position and size of each blob influences the color of other pixels in the mixing dish. Edits to the mixing dish are non-destructive, and an infinite history of color combinations is preserved.

Abstract: Stroke operation prediction techniques and systems for three-dimensional digital content are described. In one example, stroke operation data is received that describes a stroke operation input via a user interface as part of the three-dimensional digital content. A cycle is generated that defines a closed path within the three-dimensional digital content based on the input stroke operation and at least one other stroke operation in the user interface. A surface is constructed based on the generated cycle. A predicted stroke operation is generated based at least in part on the constructed surface. The predicted stroke operation is then output in real time in the user interface as part of the three-dimensional digital content as the stroke operation data is received.

Abstract: Stroke operation prediction techniques and systems for three-dimensional digital content are described. In one example, stroke operation data is received that describes a stroke operation input via a user interface as part of the three-dimensional digital content. A cycle is generated that defines a closed path within the three-dimensional digital content based on the input stroke operation and at least one other stroke operation in the user interface. A surface is constructed based on the generated cycle. A predicted stroke operation is generated based at least in part on the constructed surface. The predicted stroke operation is then output in real time in the user interface as part of the three-dimensional digital content as the stroke operation data is received.

Abstract: Stroke operation prediction techniques and systems for three-dimensional digital content are described. In one example, stroke operation data is received that describes a stroke operation input via a user interface as part of the three-dimensional digital content. A cycle is generated that defines a closed path within the three-dimensional digital content based on the input stroke operation and at least one other stroke operation in the user interface. A surface is constructed based on the generated cycle. A predicted stroke operation is generated based at least in part on the constructed surface. The predicted stroke operation is then output in real time in the user interface as part of the three-dimensional digital content as the stroke operation data is received.

Abstract: An interactive palette interface includes a color picker for digital paint applications. A user can create, modify and select colors for creating digital artwork using the interactive palette interface. The interactive palette interface includes a mixing dish in which colors can be added, removed and rearranged to blend together to create gradients and gamuts. The mixing dish is a digital simulation of a physical palette on which an artist adds and mixes various colors of paint before applying the paint to the artwork. Color blobs, which are logical groups of pixels in the mixing dish, can be spatially rearranged and scaled by a user to create and explore different combinations of colors. The color, position and size of each blob influences the color of other pixels in the mixing dish. Edits to the mixing dish are non-destructive, and an infinite history of color combinations is preserved.

Abstract: An interactive palette interface includes a color picker for digital paint applications. A user can create, modify and select colors for creating digital artwork using the interactive palette interface. The interactive palette interface includes a mixing dish in which colors can be added, removed and rearranged to blend together to create gradients and gamuts. The mixing dish is a digital simulation of a physical palette on which an artist adds and mixes various colors of paint before applying the paint to the artwork. Color blobs, which are logical groups of pixels in the mixing dish, can be spatially rearranged and scaled by a user to create and explore different combinations of colors. The color, position and size of each blob influences the color of other pixels in the mixing dish. Edits to the mixing dish are non-destructive, and an infinite history of color combinations is preserved.

Abstract: A method, system, and computer-readable storage medium are disclosed for simulation of a stateful brush tip. A tip of a brush tool is modeled using a data structure. A user input is collected representing a stroke made on a virtual canvas with the brush tool. The stroke is made with the tip in a first state. A second state of the tip is determined dependent on the first state of the tip and the user input. The second state represents a different shape of the tip than the first state. The second state of the tip is stored using the data structure.

Abstract: An interactive palette interface includes a color picker for digital paint applications. A user can create, modify and select colors for creating digital artwork using the interactive palette interface. The interactive palette interface includes a mixing dish in which colors can be added, removed and rearranged to blend together to create gradients and gamuts. The mixing dish is a digital simulation of a physical palette on which an artist adds and mixes various colors of paint before applying the paint to the artwork. Color blobs, which are logical groups of pixels in the mixing dish, can be spatially rearranged and scaled by a user to create and explore different combinations of colors. The color, position and size of each blob influences the color of other pixels in the mixing dish. Edits to the mixing dish are non-destructive, and an infinite history of color combinations is preserved.

Abstract: Stroke operation prediction techniques and systems for three-dimensional digital content are described. In one example, stroke operation data is received that describes a stroke operation input via a user interface as part of the three-dimensional digital content. A cycle is generated that defines a closed path within the three-dimensional digital content based on the input stroke operation and at least one other stroke operation in the user interface. A surface is constructed based on the generated cycle. A predicted stroke operation is generated based at least in part on the constructed surface. The predicted stroke operation is then output in real time in the user interface as part of the three-dimensional digital content as the stroke operation data is received.

Abstract: Systems and methods for providing a natural media painting application may receive user inputs through tablet stylus gestures. A user interface may detect stylus gestures that mimic real-world actions of artists based on information collected during user manipulation of the stylus, and may map the gestures to various digital painting and image editing tasks that may be invoked and/or controlled using the gesture-based inputs. The collected information may include spatial and/or directional information, acceleration data, an initial and/or ending position of the stylus, an initial and/or ending orientation of the stylus, and/or pressure data. The stylus gestures may include translations, rotations, twisting motions, mashing gestures, or jerking motions.

Abstract: A method, system, and computer-readable storage medium are disclosed for simulation of an erodible tip. A brush tool representing an erodible media is modeled as a height map. Information is collected about a user manipulation of a stylus representing a stroke made on a virtual canvas with the brush tool. A mark to be made on the virtual canvas is determined dependent on the brush tool model and the collected information. The determined mark is rendered. A change in the height map of the brush tool due to the stroke is determined dependent on the brush tool model and the collected information. One or more subsequent marks are rendered in response to manipulation of the brush tool dependent on the determined change in the height map.

Abstract: Implementations relate to relate to rectification of distortion in an image. In some implementations, a method includes extracting edgelets from an image, each edgelet defined by a location of a pixel having an edge depicted in the image and defined by a direction of the edge. The method finds at least one vanishing point in the image based on intersections of pairs of the edges of the edgelets. Each vanishing point is selected based on a plurality of the edgelets in the image having edges approximately aligned with the vanishing point. Found vanishing points are used to transform the image to reduce image distortion.

Abstract: A method, system, and computer-readable storage medium are disclosed for simulation of an erodible tip. A brush tool representing an erodible media is modeled as a height map. Information is collected about a user manipulation of a stylus representing a stroke made on a virtual canvas with the brush tool. A mark to be made on the virtual canvas is determined dependent on the brush tool model and the collected information. The determined mark is rendered. A change in the height map of the brush tool due to the stroke is determined dependent on the brush tool model and the collected information. One or more subsequent marks are rendered in response to manipulation of the brush tool dependent on the determined change in the height map.

Abstract: Implementations relate to relate to rectification of distortion in an image. In some implementations, a method includes extracting edgelets from an image, each edgelet defined by a location of a pixel having an edge depicted in the image and defined by a direction of the edge. The method finds at least one vanishing point in the image based on intersections of pairs of the edges of the edgelets. Each vanishing point is selected based on a plurality of the edgelets in the image having edges approximately aligned with the vanishing point. Found vanishing points are used to transform the image to reduce image distortion.

Abstract: Systems and methods for synthesizing paintbrush strokes may use high fidelity pose data of reference strokes to supplement lower dimension stroke data. For example, 6DOF data representing reference strokes created by skilled artists may be captured and stored in a library of reference strokes. A query stroke made by a less skilled artist/user and/or made using input devices that do not provide 6DOF data may be processed by a stroke synthesis engine to produce an output stroke that follows the trajectory of the query stroke and includes pose data from one or more reference strokes. The stroke synthesis engine may construct feature vectors for samples of reference strokes and query strokes, select the best neighbor feature vector from the library for each query stroke sample, assign the pose data of the best neighbor to the query sample, and smooth the sequence of assigned poses to produce the synthesized output stroke.

Abstract: A method, system, and computer-readable storage medium are disclosed for simulation of an erodible tip. A brush tool representing an erodible media is modeled as a height map. Information is collected about a user manipulation of a stylus representing a stroke made on a virtual canvas with the brush tool. A mark to be made on the virtual canvas is determined dependent on the brush tool model and the collected information. The determined mark is rendered. A change in the height map of the brush tool due to the stroke is determined dependent on the brush tool model and the collected information. One or more subsequent marks are rendered in response to manipulation of the brush tool dependent on the determined change in the height map.

Abstract: Techniques for improving the performance of vector-based, fluid motion simulation techniques. The techniques may be implemented in procedural painting algorithms that employ a vector-based, fluid motion simulation technique to help achieve dynamic, serendipitous behaviors of painting at good interactive rates even on relatively low-powered devices. Instead of employing polygons in a procedural painting algorithm that are combinations of pigment and water, a technique may be employed in which the polygons are separated into pigment polygons and water polygons. The water polygons are not rendered; only the pigment polygons are rendered. To improve the performance of the wetness determination at vertices of the pigment polygons, a technique may be used that first rasterizes all of the water polygons into a buffer, which may be referred to as a wetness layer or wetmap; the wetness at a vertex is then determined by sampling this buffer or layer at the vertex's position.

Abstract: Techniques for improving the performance of vector-based, fluid motion simulation techniques in procedural painting algorithms. The techniques may be implemented in procedural painting algorithms that employ a vector-based, fluid motion simulation technique to help achieve dynamic and serendipitous behaviors of watercolor painting at good interactive rates even on relatively low-powered devices. The techniques may include resampling the vertices of pigment polygons after growth at least at some iterations of the algorithm to provide smoother, more uniform growth; rasterizing dried pigment polygons into a texture so that the dried polygons are not rendered at each iteration of the algorithm; and rendering only a subset of live pigment polygons at each iteration of the algorithm. Polygons used by the techniques may be separated into static water polygons and dynamic pigment polygons.

Abstract: A graphics application for simulating natural media drawing and painting may model a tablet stylus as if it were a virtual projector, and as if a 2D brush tip image were projected on a virtual canvas. The application may compute a texture projection based on the values of configurable parameters of the application and/or 6DOF data collected from the tablet stylus and/or the tablet. This texture projection (i.e., the mark resulting from deformation of the 2D brush tip image due to the stylus pose) may be used as a 2D stamp to create a mark on the virtual canvas in response to contact between the stylus and tablet. This may create a more natural mapping between tablet stylus poses and the resulting marks for artists accustomed to the behavior of pencils, felt tip pens, airbrushes, or another natural media, compared to those employed in previous digital painting applications.

Abstract: A graphics application for simulating natural media drawing and painting may model a tablet stylus as if it were a virtual airbrush tool that sprays paint on a virtual canvas (tablet). The application may compute a conical shape of the paint spray, a target area in which to create an airbrush mark, and a target distribution of the paint to be deposited within the target area based on values of configurable parameters of the application and on 6DOF data collected from the tablet stylus and the tablet. The target distribution shape may be based on a hardness parameter. The virtual airbrush tool may create the mark using texture projection or by emitting multiple individual paint particles, which may have random sizes and velocity directions. In a hybrid mode, a granularity parameter may control the relative contributions of texture projection and particle emission in creating a given airbrush mark.