T3.0V02-PolygonPanellingTutorial

GRASSHOPPER TUTORIAL 03 POLYGON PANELLING TUTORIAL

IDEA

POLYGON PANELLING

THIS TUTORIAL WILL PANEL A SURFACE WITH A SPECIFIED GRID OF POLYLINES USING TRIANGULAR, RECTANGULAR, GEXAGONAL AND RADIAL GRIDS. THROUGH THIS EXERCISE SURFACE TOPOLOGY CONCEPTS WILL ALSO BE INTRODUCED SUCH AS DOMAIN, UV COORDINATES, REMAPPING AND REPARAMETISATION.

GH TUTORIAL - 03 POLYGON PANELLING DAVID LISTER, JAS JOHNSTON - 28082011

EXERCISE CREATE A SURFACE IN RHINO OR GRASSHOPPPER THAT WILL BE USED AS THE BASE SURFACE TO EVALUATE A GRID ONTO. CREATE A POLYGONAL GRID USING ONE OF THE GRID COMPONENTS. THIS GRID WILL BE EVALUATED ONTO THE SURFACE CREATED IN RHINO TO PANEL THE SURFACE.

(VECTOR/GRIDS/RECGRID) SET THE NUMBER OF GRID CELLS IN BOTH X AND Y DIRECTIONS USING INTEGER NUMBER SLIDERS. THE CELL SIZE PARAMETERS ARE IRRELEVANT AS WE WILL REPARAMETERISE THE SURFACE AND GRID DOMAIN TO MATCH EACH OTHER. WHEN THE GRID IS THEN MAPPED ONTO THE SURFACE THE SIZE OF THE CELLS IS DETERMINED BY THE UV COORDINATES OF THE SURFACE.

OTHER GRID TYPES WILL WORK IN EXACTLY THE SAME WAY AND THEREFORE CAN EASILY BE INTERCHANGED

IN ORDER TO MAP THE GRID ONTO THE SURFACE WE NEED TO FIND THE VERTEX POINTS OF THE GRID AND THE X AND Y COORDINATES OF THESE POINTS WHICH CAN THEN BE REMAPPED TO HAVE THE SAME DOMAIN AS THE UV CO-ORDINATES OF THE SURFACE. THIS IS ACHIEVED BY FINDING THE DISCONTINUITIES OF THE CURVES.

(CURVE/ANALYSIS/DISC)

THE POINTS EXTRACTED AT THE DISCONTINUITIES OF THE CURVES CAN THEN BE DECOMPOSED INTO X, Y AND Z AXIS INFORMATION.

(VECTOR/POINT/pCOMP)

GH TUTORIAL - 03 POLYGON PANELLING DAVID LISTER, JAS JOHNSTON - 28082011

EXERCISE THE X AND Y COORDINATES MUST ME REMAPPED TO MATCH THE DOMAIN OF THE SURFACE. AS THE SURFACE DOMAIN WILL BE REPARAMETERISED TO 0 - 1, WE MUST ENSURE THE DOMAIN OF THE GRID IS ALSO 0 - 1.

(MATH/DOMAIN/REMAP)

TO REMAP THE DOMAIN WE MUST FIRST DETERMINE THE BOUNDS OF THE EXISTING DOMAIN OF THE GRID. BOUNDS GIVES THE LARGEST AND SMALLEST VALUES OF THE DOMAIN.

(MATH/DOMAIN/BOUNDS 2D) BOUNDS 2D MUST BE USED TO EXTRACT THE BOUNDS OF THE DOMAIN IN BOTH THE U AND V DIRECTION.

FLATTEN THE DATA PATH BEING INPUT INTO THE BOUNDS 2D COMPONENT BY EITHER USING THE FLATTEN COMPONENT (AS SHOWN ABOVE), OR RIGHT CLICKING ON THE “C” INPUT AND SELECTING “FLATTEN”.

(SETS/TREE/FLATTEN TREE)

DECOMPOSE THE 2D NUMERIC DOMAIN INTO SEPARATE DOMAINS I.E. THE U AND V DOMAINS

BY USING THE DOMAIN2 COMPONENT. (MATHS/DOMAIN/DOMAIN2 COMPONENT) NB: SELECTE THE DOMAIN2 COMPONENT WHICH DECOMPOSES A 2D DOMAIN INTO SEPARATE DOMAINS.

PASS THE EXTRACTED U AND V DOMAINS OF THE GRID TO THE SOURCE DOMAIN INPUT OF THE REMAP COMPONENT

GH TUTORIAL - 03 POLYGON PANELLING DAVID LISTER, JAS JOHNSTON - 28082011

EXERCISE SET THE TARGET DOMAIN FOR THE REMAP COMPONENT BY PASSING A DOMAIN COMPONENT INTO THE T INPUTS. SET THE A INPUT OF THE DOMAIN COMPONENT TO 0 AND THE B INPUT TO 1 BY RIGHT CLICKING THE INPUTS AND SELECTED “SET NUMBER.”

(MATHS/DOMAIN/DOMAIN)

RECREATE THE GRID POINTS WITHIN THEIR NEW DOMAIN USING THE POINT XYZ COMPONENT.

(VECTOR/POINT/POINT XYZ)

REFERENCE TARGET SURFACE FROM RHINO

USING THE EVALUATE SURFACE COMPONENT, EVALUATE THESE REMAPPED U AND V VALUES ON THE TARGET SURFACE. THE EVALUATE COMPONENT PROVIDES THE POINT, NORMAL AND FRAME INFORMATION FOR THE MAPPED POINTS ON THE NEW SURFACE.

(SURFACE/ANALYSIS/EVAL SURFACE)

REPARAMATISE THE INPUT SURFACE TO ENSURE IT HAS A DOMAIN OF 0 -1 LIKE THE REMAPPED GRID

BY RIGHT CLICKING ON THE SURFACE INPUT AND SELECTING REPARAMETISE.

GH TUTORIAL - 03 POLYGON PANELLING DAVID LISTER, JAS JOHNSTON - 28082011

REJOIN THE SETS OF POINTS INTO THEIR POLYGONAL LINES BY USING THE POLYLINE COMPONENT.

(CURVE/SPLINE/POLYLINE)

THE DEFINITION CAN NOW BE SWITCHED FROM A TRIANGULAR TO HEXAGONAL GRID...

AND TO A RADIAL GRID

GH TUTORIAL - 03 POLYGON PANELLING DAVID LISTER, JAS JOHNSTON - 28082011