公开(公告)号：BR8703887A

公开(公告)日：1988-03-29

申请号：BR8703887

申请日：1987-07-27

Applicant: IBM

Inventor： QUARENDON PETER

IPC: G06F17/50 ,  G06T17/00 ,  G06T17/10 ,  G06F15/72

Abstract: A method of generating a spatial representation of a 3-D solid object which comprises component shapes which can be defined by transforming constructive solid geometry primitives comprises the steps of setting up a structure (in 72) to define the object in terms of the primitives and transforms and setting up a definition of a 3-D box (in 54) in world space and then sub-dividing (in 60) the box into sub-boxes, generating test-cells in object space by performing (in 62, 64) on the sub-boxes the inverse (from 56) of each transformation to be performed on the primitives to create the object and determining (in 66) which of the test-cells intersect the object. Thus, the need to transform the object primitives is avoided. A particular application of the method is the generation of 2-D images of a 3-D solid object. A solid modelling system comprising means for performing the method is defined.

公开(公告)号：AU7779787A

公开(公告)日：1988-03-10

申请号：AU7779787

申请日：1987-09-03

Applicant: IBM

Inventor： QUARENDON PETER ,  TODD STEPHEN JAMES PAUL

IPC: G06T11/00 ,  G06T15/20 ,  G06T17/00 ,  G06K9/46 ,  G06K9/20

公开(公告)号：DE3071163D1

公开(公告)日：1985-11-14

申请号：DE3071163

申请日：1980-07-01

Applicant: IBM

Inventor： TUFFILL HAROLD WILLIAM ,  JOHNSON PETER WILLIAM ,  HARDIMAN RAYMOND ,  HALL STEPHEN THOMAS ,  QUARENDON PETER

IPC: G06F3/153 ,  G06F17/21 ,  G06T11/20 ,  G09G5/22 ,  G09G5/24 ,  G09G5/36 ,  G09G5/40 ,  G09G1/16

公开(公告)号：AU545063B2

公开(公告)日：1985-06-27

申请号：AU6267980

申请日：1980-09-24

Applicant: IBM

Inventor： MITCHELL JOAN L ,  QUARENDON PETER

IPC: G06F5/00 ,  G06T9/00 ,  H03M7/30 ,  H04N1/415 ,  H04N7/12 ,  G06F3/14

Abstract: A compression technique for a character graphics system in which character cell definition bit strings are transmitted from a central processing unit to a display unit. Each cell is divided into a number of slices and each slice into digits. A test is made on whether to compress on a comparison with an all zero slice, the previous slice or the previous slice but one, depending upon the number of digit mismatches that occur when the comparison occurs. Slices are then compressed by comparing each digit with the corresponding digit in the comparison slice and generating a single 0 bit if the digit matches and including a 1 bit and the whole digit if a mismatch occurs. The compression in the central processing unit and the decompression in the display unit is implemented in microcoded routines.