摘要:
A computer implemented method for deforming a 3D polygon mesh using non-linear and linear constraints. The method includes creating a coarse control 3D polygon mesh that completely encapsulates the 3D polygon mesh to be deformed, projecting the deformation energy of the 3D polygon mesh and the constraints of the 3D polygon mesh to the vertices, or subspace, of the coarse control 3D polygon mesh, and determining the resulting deformed 3D polygon mesh by iteratively determining the deformation energy of the subspace. The constraints may be either linear or non-linear constraints, for example, a Laplacian constraint, a position constraint, a projection constraint, a skeleton constraint, or a volume constraint.
摘要:
Surfaces can be decorated with texture tiling and/or texture painting using one or more sample textures, such as BTFs. In a described implementation of texture tiling, a patch-based BTF synthesis algorithm is utilized. In an example embodiment, a mesh of a target surface is re-sampled to produce a dense mesh such that there is a one-to-one correspondence between vertices of the dense mesh and pixels of an image. Patch matching is then employed with a working image that corresponds to a working patch. In an example embodiment, the patch matching is effectuated using translations and rotations of the sample texture. In a described implementation of texture painting, irregular feature(s) of a sample texture are synthesized onto a target surface. In an example embodiment, user-specified constraints as to a desired foreground feature of a sample texture and an intended foreground region of a targeted surface are factored into a graphcut operation.
摘要:
A real-time algorithm for rendering an inhomogeneous scattering medium such as fog is described. An input media animation is represented as a sequence of density fields, each of which is decomposed into a weighted sum of a set of radial basis functions (RBFs) such as Gaussians. The algorithm computes airlight and surface reflectance of the inhomogeneous scattering medium. Several approximations are taken which lead to analytical solutions of quantities such as an optical depth integrations and single scattering integrations, and a reduced number of integrations that need to be calculated. The resultant algorithm is able to render inhomogeneous media including their shadowing and scattering effects in real time. The algorithm may be adopted for a variety of light sources including point lights and environmental lights.
摘要:
Surfaces can be decorated with texture tiling and/or texture painting using one or more sample textures, such as BTFs. In a described implementation of texture tiling, a patch-based BTF synthesis algorithm is utilized. In an example embodiment, a mesh of a target surface is re-sampled to produce a dense mesh such that there is a one-to-one correspondence between vertices of the dense mesh and pixels of an image. Patch matching is then employed with a working image that corresponds to a working patch. In an example embodiment, the patch matching is effectuated using translations and rotations of the sample texture. In a described implementation of texture painting, irregular feature(s) of a sample texture are synthesized onto a target surface. In an example embodiment, user-specified constraints as to a desired foreground feature of a sample texture and an intended foreground region of a targeted surface are factored into a graphcut operation.
摘要:
Large mesh deformation using the volumetric graph Laplacian is described. In one aspect, information is received from a user, wherein the information indicates how an original mesh is to be deformed. The original mesh is then deformed based on the information and application of a volumetric differential operator to a volumetric graph generated from the original mesh.
摘要:
A real-time algorithm for rendering of an inhomogeneous scattering media such as smoke under dynamic low-frequency environment lighting is described. An input media animation is represented as a sequence of density fields, each of which is decompressed into a weighted sum of a set of radial basis functions (RBFs) and an optional residual field. Source radiances from single and optionally multiple scattering are directly computed at only the RBF centers and then approximated at other points in the volume using an RBF-based interpolation. Using the computed source radiances, a ray marching technique using slice-based integration of radiance along each viewing ray is performed to render the final image. During the ray marching process, the residual field may be compensated back into the radiance integral to generate images of higher detail.
摘要:
A real-time algorithm for rendering of an inhomogeneous scattering media such as smoke under dynamic low-frequency environment lighting is described. An input media animation is represented as a sequence of density fields, each of which is represented by an approximate model density field and a residual density field. The algorithm uses the approximate model density field to compute an approximate source radiance, and further computes an effective exitant radiance by compositing the approximate source radiance using a compositing methods such as ray marching. During the compositing process (e.g., ray marching), the residual field is compensated back into the radiance integral to generate images of higher detail.
摘要:
A “texture generator” uses an inverse texture synthesis solution that runs in the opposite direction to traditional forward synthesis techniques to construct 2D texture compactions for use by a graphics processing unit (GPU) of a computer system. These small 2D texture compactions generally summarize an original globally variant texture or image, and are used to reconstruct the original texture or image, or to re-synthesize new textures or images under user-supplied constraints. In various embodiments, the texture generator uses the texture compaction to provide real-time synthesis of globally variant textures on a GPU, where texture memory is generally too small for large textures. Further, the texture generator provides an optimization framework for inverse texture synthesis which ensures that each input region is properly encoded in the output compaction. In addition, the texture generator also computes orientation fields for anisotropic textures containing both low- and high-frequency regions.
摘要:
A real-time algorithm for rendering of an inhomogeneous scattering medium such as fog with a surface object immersed therein is described. An input media animation is represented as a sequence of density fields. The algorithm computes surface reflectance of the surface object in the inhomogeneous scattering medium. The algorithm may also compute airlight of the inhomogeneous scattering medium. Several approximations are taken which lead to analytical solutions of quantities such as optical depth integrations and single scattering integrations, and a reduced number of integrations that need to be calculated. The resultant algorithm is able to render inhomogeneous media including their shadowing and scattering effects in real time. The algorithm may be adopted for a variety of light sources including point lights and environmental lights.
摘要:
A graphics system allows for manipulation of a detail mesh for a subdivision surface. To deform the subdivision surface, the graphics system generates a corresponding deformed control mesh by attempting to satisfy both position constraints of the manipulation and Laplacian constraints for the detail mesh. After the deformed control mesh is generated, the deformed detail mesh can be generated by applying a subdivision function to the deformed control mesh to generate a deformed smooth mesh and then applying detail information to the deformed smooth mesh.