US5579456A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct rendering of textured height fields
Assignee: Rockwell Collins Simulation and Training Solutions LLC
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Filing: 1995-11-29
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Granted: 1996-11-26
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Expires: 2015-11-29
Abstract
Abstract To create a dynamic textured display, images of textured height fields (elevation samples arrayed on a rectangular coordinate grid, as to represent a terrain) are rendered, the system performing an initial pass that re-samples the height-field data into a radial form and a subsequent pass using the radial data to create textured, shaded picture elements (pixels) for an instantaneous field of view. Thus, texturing, shading, blending and scan conversion complete the pixel processing to drive a display unit. The system is particularly applicable to the generation of dynamic perspective images of terrain. The process provides pixel-limited textural resolution in the final image with effective antialiasing of internal and horizontal silhouette edges.
Inventors
- 👤 Michael A. Cosman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:06
CPC Classifications
G; G06; G06T; G06T17/00; G06T17/05; G06T15/00; G06T15/10; G06T15/20
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
182 words
A process for producing a perspective image based on height field data, said image having a foreground and a background, said process comprising the steps of: establishing a centered viewpoint for said perspective image; sampling said height field data to generate a radial form height field, said height field having a relatively greater level of detail for said foreground and a relatively lesser level of detail for said background, said sampling step including: defining rays extending radially from said centered viewpoint in model space, said rays being substantially parallel in image space; and sampling said height field data at selected locations along said rays in model space to provide height samples, said locations forming vertices of substantially square trapezoidal shapes in model space, said shapes increasing in size with increasing radial distance from said centered viewpoint in model space, but being substantially uniform in image space; processing picture elements in relation to said viewpoint based on said radial form height field to provide perspective display data; and driving a display in accordance with said perspective display data to provide said perspective image.
Claim 2
Dependent Claim
182 words
A process for producing a perspective image based on height field data, said image having a foreground and a background, said process comprising the steps of: establishing a centered viewpoint for said perspective image; sampling said height field data to generate a radial form height field, said height field having a relatively greater level of detail for said foreground and a relatively lesser level of detail for said background, said sampling step including: defining rays extending radially from said centered viewpoint in model space, said rays being substantially parallel in image space; and sampling said height field data at selected locations along said rays in model space to provide height samples, said locations forming vertices of substantially square trapezoidal shapes in model space, said shapes increasing in size with increasing radial distance from said centered viewpoint in model space, but being substantially uniform in image space; processing picture elements in relation to said viewpoint based on said radial form height field to provide perspective display data; and driving a display in accordance with said perspective display data to provide said perspective image.
Claim 3
Dependent Claim
38 words
A process according to claim 1 wherein said step of sampling said height field data includes defining a system of azimuth and range coordinates such that adjacent sets of said coordinate points define said substantially square trapezoidal shapes.
Claim 4
Dependent Claim
27 words
A process according to claim 1 wherein said step of processing picture elements includes defining and interconnecting a system of azimuth and range coordinates to provide polygons.
Claim 5
Dependent Claim
13 words
A process according to claim 3 wherein said polygons are defined as triangles.
Claim 6
Dependent Claim
23 words
A process according to claim 3 wherein said picture elements are processed by combining values selectively from said polygons proximate each picture element.
Claim 7
Dependent Claim
20 words
A process according to claim 1 wherein said step of processing said picture elements further includes texturing said picture elements.
Claim 8
Dependent Claim
20 words
A process according to claim 1 wherein said step of processing said picture elements further includes shading said picture elements.
Claim 9
Dependent Claim
26 words
A process according to claim 1 wherein said step of processing said picture elements further includes scan converting said picture elements to a raster display format.
Claim 10
Dependent Claim
75 words
A process according to claim 1 wherein said step of sampling said height field data includes defining a system of azimuth and range coordinates such that adjacent sets of said coordinate points define said substantially square trapezoidal shapes to provide polygons and wherein said picture elements are processed by combining values selectively from said polygons proximate each picture element and further, texturing said picture elements, shading said picture elements and scan converting said picture elements.
Claim 11
Independent Claim
194 words
A system for producing perspective images having a foreground and a background with respect to a selected viewpoint, as of a terrain, comprising: memory means for storing a height field, as to represent a terrain; radial means for providing radial height field data from said memory means in a re-sampled radial coordinate form, said re-sampled radial coordinate form providing a relatively greater level of detail for said foreground and a relatively lesser level of detail for said background and defining: rays extending radially from said viewpoint in model space, said rays being substantially parallel in image space; and selected re-sampling locations along said rays in model space providing re-sampled heights, said locations forming vertices of substantially square trapezoidal shapes in model space, said shapes increasing in size with increasing radial distance from said centered viewpoint in model space, but being substantially uniform in image space; an image generator means including a pixel processor for receiving said radial height field data from said radial means to formulate display pixel data indicative of said height field with respect to said selected viewpoint; and display means for receiving said display pixel data to display said perspective representation.
Claim 12
Independent Claim
194 words
A system for producing perspective images having a foreground and a background with respect to a selected viewpoint, as of a terrain, comprising: memory means for storing a height field, as to represent a terrain; radial means for providing radial height field data from said memory means in a re-sampled radial coordinate form, said re-sampled radial coordinate form providing a relatively greater level of detail for said foreground and a relatively lesser level of detail for said background and defining: rays extending radially from said viewpoint in model space, said rays being substantially parallel in image space; and selected re-sampling locations along said rays in model space providing re-sampled heights, said locations forming vertices of substantially square trapezoidal shapes in model space, said shapes increasing in size with increasing radial distance from said centered viewpoint in model space, but being substantially uniform in image space; an image generator means including a pixel processor for receiving said radial height field data from said radial means to formulate display pixel data indicative of said height field with respect to said selected viewpoint; and display means for receiving said display pixel data to display said perspective representation.
Claim 13
Dependent Claim
39 words
A system according to claim 10 wherein said radial means comprises means to access said memory means to receive height field data and re-sample said height field data into radial height field data based on azimuth and range coordinates.
Claim 14
Dependent Claim
30 words
A system according to claim 11 wherein said radial means further includes means for blending values of said height field data to provide values of said radial height field data.
Claim 15
Dependent Claim
27 words
A system according to claim 10 wherein said image generator means includes means to formulate polygons representative of terrain skin whereby to formulate said display pixel data.
Claim 16
Dependent Claim
20 words
A system according to claim 13 wherein said image generator means further includes means to texture said display pixel data.
Claim 17
Dependent Claim
20 words
A system according to claim 13 wherein said image generator means further includes means to shade said display pixel data.
Claim 18
Dependent Claim
21 words
A system according to claim 13 wherein said image generator means further includes means to scan convert said display pixel data.
Claim 19
Dependent Claim
31 words
A system according to claim 13 wherein said image generator means further includes means for processing individual pixels for said perspective representation with respect to said polygons contiguous to each pixel.
Claim 20
Dependent Claim
21 words
A system according to claim 17 wherein said image generator means further includes filter means for blending values from said polygons.
Claim 21
Dependent Claim
42 words
A process according to claim 1 wherein said height samples form vertices of polygons in image space, said image space being defined by a THETA/PHI coordinate system and said step of processing picture elements includes scan-converting said polygons using a PHI-directional filter.
Claim 22
Dependent Claim
23 words
A process according to claim 19 wherein radial edges of said polygons are in alignment with said rays in said THETA/PHI image space.
Claim 23
Dependent Claim
26 words
A process according to claim 20 wherein said step of processing picture elements includes texturing said polygons in accordance with said radial edges of said polygons.
Claim 24
Dependent Claim
30 words
A process according to claim 20 wherein said step of processing picture elements includes rendering anti-aliased ridgelines in said image space in accordance with said radial edges of said polygons.
Claim 25
Dependent Claim
29 words
A process according to claim 21 wherein said step of texturing involves MIP-map, an appropriate level of which is selected in accordance with said radial edges of said polygons.
Claim 26
Dependent Claim
26 words
A process according to claim 22 wherein said step of rendering anti-aliased ridgelines includes generating a PHI list based on said radial edges of said polygons.
Claim 27
Dependent Claim
41 words
A process according to claim 1 wherein said height samples form vertices of polygons in image space defined by a THETA/PHI coordinate system and said step of processing said picture elements includes determining which of said polygons influence said picture elements.
Claim 28
Dependent Claim
32 words
A process according to claim 1 wherein said height samples are addressed in a THETA/PHI coordinate system and each includes an X-Y position in said height field data and a filtered Z-height.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-11-26 | 2000-05-27 | 2000-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-26 | 2004-05-27 | 2004-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-26 | 2008-05-27 | 2008-11-26 | $7700.00 | Window Closed / Lapsed |