초록 ▼

Surfaces of an object are rendered in the order from a surface remotest from a viewpoint. When a rear surface, e.g., a rear surface, is to be rendered, a range, i.e., a range of a texture to be used, projected by way of perspective projection with vectors which are directed from the viewpoint toward

Surfaces of an object are rendered in the order from a surface remotest from a viewpoint. When a rear surface, e.g., a rear surface, is to be rendered, a range, i.e., a range of a texture to be used, projected by way of perspective projection with vectors which are directed from the viewpoint toward a background image and take into account refractions at vertexes of the surface is determined, and the texture in the determined range is mapped onto the surface. When a front surface, e.g., a front surface, is to be rendered, a range, i.e., a range of a texture to be used, projected by way of perspective projection with vectors which are directed from the viewpoint toward a background image and take into account refractions at vertexes of the surface is determined, and the texture in the determined range is mapped onto the surface.

대표청구항 ▼

1. A method of automatically rendering an image, comprising:selecting a surface of a transparent or semi-transparent light-refracting object having a plurality of surfaces, the selected surface being remote from a virtual viewpoint;selecting a first range of a background image portion disposed behin

1. A method of automatically rendering an image, comprising:selecting a surface of a transparent or semi-transparent light-refracting object having a plurality of surfaces, the selected surface being remote from a virtual viewpoint;selecting a first range of a background image portion disposed behind the object as viewed from the virtual viewpoint, the first range being selected by perspective projection using first vectors directed from the virtual viewpoint towards the background image portion, taking into account refractions at vertexes of the remote surface;employing the first range of the background image portion as a texture to render the remote surface;thereafter, selecting a second surface of the object, the second surface being closer to the virtual viewpoint than the remote surface;selecting a second range of the background image portion by perspective projection using second vectors directed from the virtual viewpoint towards the background image portion, taking into account refractions at vertexes of the second surface; andemploying the second range of the background image portion as a texture to render the second surface.2. The method as claimed in claim 1, whereinthe first vectors include first line segments directed from the virtual viewpoint towards the vertexes of the remote surface and second line segments directed from the vertexes of the remote surface towards the background image portion, the first line segments being disposed at incident angles with respect to normals to the remote surface and the second line segments being disposed at second angles with respect to normals to the remote surface, the second angles being determined by refractions according to the incident angles at the remote surface, andthe second vectors include first line segments directed from the virtual viewpoint towards the vertexes of the second surface and second line segments directed from the vertexes of the second surface towards the background image portion, the first line segments being disposed at incident angles with respect to normals to the second surface and the second line segments being disposed at second angles with respect to normals to the second surface, the second angles being determined by refractions according to the incident angles at the second surface.3. The method as claimed in claim 2, whereinthe second angles of the first vectors are determined by the normals at the remote surface, the incident angles of the first line segments, a refractive index of a medium occupying a space adjacent the remote surface of the object, and a refractive index of the object at the remote surface, andthe second angles of the second vectors are determined by the normals at the second surface, the incident angles of the first line segments, a refractive index of a medium occupying a space adjacent the second surface of the object, and a refractive index of the object at the second surface.4. The method as claimed in claim 2, whereinthe background image portion is disposed in a uv plane in which a u-axis and a v-axis orthogonal to the u-axis are disposed, the virtual viewpoint is displaced from the uv plane in a direction of a z-axis orthogonal to the uv plane, such that the vertexes of the remote surface and the vertexes of the second surface are located by u, v and z coordinates of the u-axis, v-axis and z-axis, respectively, and the first and second ranges of the background image portion are selected by:projecting the first line segments, the normals to the remote surface and the normals to the second surface onto a uz plane in which the u-axis and the z-axis are disposed,determining the u-coordinates of the first and second ranges of the background image portion in the uv plane based on directions of the projections of the first line segments in the uz plane, the projections of the normals to the remote surface in the uz plane and the projections of the normals to the second surface in the uz plane,projecting the first line segments, the normals to the remote surface and the normals to the second surface onto a vz plane in which the v-axis and the z-axis are disposed, anddetermining the v-coordinates of the first and second ranges of the background image portion in the uv plane based on directions of the projections of the first line segments in the vz plane, the projections of the normals to the remote surface in the vz plane and projections of the normals to the second surface in the vz plane.5. An image processing apparatus, comprising:a processor, the processor being operable to:select a surface of a transparent or semi-transparent light-refracting object having a plurality of surfaces, the selected surface being remote from a virtual viewpoint,select a first range of a background image portion disposed behind the object as viewed from the virtual viewpoint, the first range being selected by perspective projection using first vectors directed from the virtual viewpoint towards the background image portion, taking into account refractions at vertexes of the remote surface,employ the first range of the background image portion as a texture to render the remote surface,thereafter, select a second surface of the object, the second surface being closer to the virtual viewpoint than the remote surface,select a second range of the background image portion by perspective projection using second vectors directed from the virtual viewpoint towards the background image portion, taking into account refractions at vertexes of the second surface, andemploy the second range of the background image portion as a texture to render the second surface.6. The image processing apparatus as claimed in claim 5, whereinthe first vectors include first line segments directed from the virtual viewpoint towards the vertexes of the remote surface and second line segments directed from the vertexes of the remote surface towards the background image portion, the first line segments being disposed at incident angles with respect to normals to the remote surface and the second line segments being disposed at incident angles with respect to normals to the remote surface, the processor being operable to determine the second angles by refractions according to the incident angles at the remote surface, andthe second vectors include first line segments directed from the virtual viewpoint towards the vertexes of the second surface and second line segments directed from the vertexes of the second surface towards the background image portion, the first line segments being disposed at incident angles with respect to normals to the second surface and the second line segments being disposed at second angles with respect to normals to the second surface, the processor being operable to determine the second angles by refractions according to the incident angles at the second surface.7. The image processing apparatus as claimed in claim 6, whereinthe processor is operable to determine the second angles of the first vectors by the normals at the remote surface, the incident angles of the first line segments, a refractive index of a medium occupying a space adjacent the remote surface of the object, and a refractive index of the object at the remote surface, andthe processor is operable to determine the second angles of the second vectors by the normals at the second surface, the incident angles of the first line segments, a refractive index of a medium occupying a space adjacent the second surface of the object, and a refractive index of the object at the second surface.8. The image processing apparatus as claimed in claim 6, wherein the background image portion is disposed in a uv plane in which a u-axis and a v-axis orthogonal to the u-axis are disposed, and the virtual viewpoint is displaced from the uv plane in a direction of a z-axis orthogonal to the uv plane, such that the vertexes of the remote surface and the vertexes of the second surface are located by u, v and z coordinates of the u-axis, v-axis and z-axis, respectively, the processor being operable to determine the first and second ranges of the background image portion by:projecting the first line segments, the normals to the remote surface and the normals to the second surface onto a uz plane in which the u-axis and the z-axis are disposed,determining the u-coordinates of the first and second ranges of the background image portion in the uv plane based on directions of the projections of the first line segments in the uz plane, the projections of the normals to the remote surface in the uz plane and the projections of the normals to the second surface in the uz plane,projecting the first line segments, the normals to the remote surface and the normals to the second surface onto a vz plane in which the v-axis and the z-axis are disposed, anddetermining the v-coordinates of the first and second ranges of the background image portion in the uv plane based on directions of the projections of the first line segments in the vz plane, the projections of the normals to the remote surface in the vz plane and projections of the normals to the second surface in the vz plane.9. A recording medium having instructions thereon for performing a method of automatically rendering an image, the image including a background image portion, the method comprising:selecting a surface of a transparent or semi-transparent light-refracting object having a plurality of surfaces, the selected surface being remote from a virtual viewpoint;selecting a first range of a background image portion disposed behind the object as viewed from the virtual viewpoint, the first range being selected by perspective projection using first vectors directed from the virtual viewpoint towards the background image portion, taking into account refractions at vertexes of the remote surface;employing the first range of the background image portion as a texture to render the remote surface;thereafter, selecting a second surface of the object, the second surface being closer to the virtual viewpoint than the remote surface;selecting a second range of the background image portion by perspective projection using second vectors directed from the virtual viewpoint towards the background image portion, taking into account refractions at vertexes of the second surface; andemploying the second range of the background image portion as a texture to render the second surface.10. The recording medium as claimed in claim 9, whereinthe first vectors include first line segments directed from the virtual viewpoint towards the vertexes of the remote surface and second line segments directed from the vertexes of the remote surface towards the background image portion, the first line segments being disposed at incident angles with respect to normals to the remote surface and the second line segments being disposed at second angles with respect to normals to the remote surface, the second angles being determined by refractions according to the incident angles at the remote surface, andthe second vectors include first line segments directed from the virtual viewpoint towards the vertexes of the second surface and second line segments directed from the vertexes of the second surface towards the background image portion, the first line segments being disposed at incident angles with respect to normals to the second surface and the second line segments being disposed at second angles with respect to normals to the second surface, the second angles being determined by refractions according to the incident angles at the second surface.11. The recording medium as claimed in claim 9, whereinthe second angles of the first vectors are determined by the normals at the remote surface, the incident angles of the first line segments, a refractive index of a medium occupying a space adjacent the remote surface of the object, and a refractive index of the object at the remote surface, andthe second angles of the second vectors are determined by the normals at the second surface, the incident angles of the first line segments, a refractive index of a medium occupying a space adjacent the second surface of the object, and a refractive index of the object at the second surface.12. The recording medium as claimed in claim 10, whereinthe background image portion is disposed in a uv plane in which a u-axis and a v-axis orthogonal to the u-axis are disposed, the virtual viewpoint is displaced from the uv plane in a direction of a z-axis orthogonal to the uv plane, such that the vertexes of the remote surface and the vertexes of the second surface are located by u, v and z coordinates of the u-axis, v-axis and z-axis, respectively, and the first and second ranges of the background image portion are selected by:projecting the first line segments, the normals to the remote surface and the normals to the second surface onto a uz plane in which the u-axis and the z-axis are disposed,determining the u-coordinates of the first and second ranges of the background image portion in the uv plane based on directions of the projections of the first line segments in the uz plane, the projections of the normals to the remote surface in the uz plane and the projections of the normals to the second surface in the uz plane,projecting the first line segments, the normals to the remote surface and the normals to the second surface onto a vz plane in which the v-axis and the z-axis are disposed, anddetermining the v-coordinates of the first and second ranges of the background image portion in the uv plane based on directions of the projections of the first line segments in the vz plane, the projections of the normals to the remote surface in the vz plane and projections of the normals to the second surface in the vz plane.13. An image processing apparatus operable to perform a rendering method, the method comprising:selecting a surface of a transparent or semi-transparent light-refracting object having a plurality of surfaces, the selected surface being remote from a virtual viewpoint;selecting a first range of a background image portion disposed behind the object as viewed from the virtual viewpoint, the first range being selected by perspective projection using first vectors directed from the virtual viewpoint towards the background image portion, taking into account refractions at vertexes of the remote surface;employing the first range of the background image portion as a texture to render the remote surface and for selecting a second surface of the object, the second surface being closer to the virtual viewpoint than the remote surface;selecting a second range of the background image portion by perspective projection using second vectors directed from the virtual viewpoint towards the background image portion, taking into account refractions at vertexes of the second surface; andemploying the second range of the background image portion as a texture to render the second surface.14. The image processing apparatus as claimed in claim 13, whereinthe first vectors include first line segments directed from the virtual viewpoint towards the vertexes of the remote surface and second line segments directed from the vertexes of the remote surface towards the background image portion, the first line segments being disposed at incident angles with respect to normals to the remote surface and the second line segments being disposed at second angles with respect to normals to the remote surface, the method further including determining the second angles by refractions according to the incident angles at the remote surface, andthe second vectors include first line segments directed from the virtual viewpoint towards the vertexes of the second surface and second line segments directed from the vertexes of the second surface towards the background image portion, the first line segments being disposed at incident angles with respect to normals to the second surface and the second line segments being disposed at second angles with respect to normals to the second surface, the method further including determining the second angles by refractions according to the incident angles at the second surface.15. The image processing apparatus as claimed in claim 14, whereinthe method further includes determining the second angles of the first vectors by the normals at the remote surface, the incident angles of the first line segments, a refractive index of a medium occupying a space adjacent the remote surface of the object, and a refractive index of the object at the remote surface, anddetermining the second angles of the second vectors by the normals at the second surface, the incident angles of the first line segments, a refractive index of a medium occupying a space adjacent the second surface of the object, and a refractive index of the object at the second surface.16. The image processing apparatus as claimed in claim 14, wherein the background image portion is disposed in a uv plane in which a u-axis and a v-axis orthogonal to the u-axis are disposed, and the virtual viewpoint is displaced from the uv plane in a direction of a z-axis orthogonal to the uv plane, such that the vertexes of the remote surface and the vertexes of the second surface are located by u, v and z coordinates of the u-axis, v-axis and z-axis, respectively, the method further including determining the first and second ranges of the background image portion by:projecting the first line segments, the normals to the remote surface and the normals to the second surface onto a uz plane in which the u-axis and the z-axis are disposed,determining the u-coordinates of the first and second ranges of the background image portion in the uv plane based on directions of the projections of the first line segments in the uz plane, the projections of the normals to the remote surface in the uz plane and the projections of the normals to the second surface in the uz plane,projecting the first line segments, the normals to the remote surface and the normals to the second surface onto a vz plane in which the v-axis and the z-axis are disposed, anddetermining the v-coordinates of the first and second ranges of the background image portion in the uv plane based on directions of the projections of the first line segments in the vz plane, the projections of the normals to the remote surface in the vz plane and projections of the normals to the second surface in the vz plane.