# how to draw a 3d pyramid using patch

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Udit Saxena on 26 Dec 2019
Commented: Andreas Bernatzky on 31 Dec 2019
Andreas Bernatzky on 31 Dec 2019

Andreas Bernatzky on 27 Dec 2019
Hope that suits you. Did it in an Objectorientated approach because I think this can be reused easier
Some theory for patch which I have used:
For class:
classdef pyramid
%PYRAMID Summary of this class goes here
% class for drawing a simple 3D pyramid
%% Andreas Bernatzky 27.12.2019
%%
properties
cX; %centerpointX
cY; %centerpointY
cZ; %centerpointZ
p; %pyramidlength
height; %height of the pyramid
end
methods
function obj = pyramid(centerX,centerY,centerZ,pyramidBot,height)
%PYRAMID Construct an instance of this class
obj.cX = centerX;
obj.cY = centerY;
obj.cZ = centerZ;
obj.p = pyramidBot;
obj.height = height;
end
function drawPyramid(obj)
%drawPyramid
% visualise a pyramid obj
figure()
hold on
% Define the first sideFace (myDefault face) by vertices
% Face 1 vertices create manually
xFace1 = [obj.cX - obj.p; obj.cX + obj.p; obj.cX]; %xcoordinates of face1 vertices
yFace1 = [obj.cY - obj.p; obj.cY - obj.p; obj.cY]; %ycoordinates of face1 vertices
zFace1 = [obj.cZ; obj.cZ; obj.cZ + obj.height]; %zcoordinates of face1 vertices
% Face 2 vertices (create by rotation)
xFace2 = cos(pi/2) * (xFace1 - obj.cX) - sin(pi/2) * (yFace1 - obj.cY) + obj.cX; %xcoordinates of face2 vertices
yFace2 = sin(pi/2) * (xFace1 - obj.cX) + cos(pi/2) * (yFace1 - obj.cY) + obj.cY; %ycoordinates of face2 vertices
zFace2 = zFace1;%zcoordinates of face2 vertices just a copy not really needed
% Face 3 vertices (create by rotation)
xFace3 = cos(pi) * (xFace1 - obj.cX) - sin(pi) * (yFace1 - obj.cY) + obj.cX; %xcoordinates of face3 vertices
yFace3 = sin(pi) * (xFace1 - obj.cX) + cos(pi) * (yFace1 - obj.cY) + obj.cY; %ycoordinates of face3 vertices
zFace3 = zFace1;%zcoordinates of face3 vertices just a copy not really needed
% Face 4 vertices (create by rotation)
xFace4 = cos(pi + pi/2) * (xFace1 - obj.cX) - sin(pi + pi/2) * (yFace1 - obj.cY) + obj.cX; %xcoordinates of face4 vertices
yFace4 = sin(pi + pi/2) * (xFace1 - obj.cX) + cos(pi + pi/2) * (yFace1 - obj.cY) + obj.cY; %ycoordinates of face4 vertices
zFace4 = zFace1;%zcoordinates of face4 vertices just a copy not really needed
%[xcolumn,ycolumn,zcolumn]
PyramidVertices = [xFace1 yFace1 zFace1; xFace2 yFace2 zFace2; xFace3 yFace3 zFace3; xFace4 yFace4 zFace4];
PyramidFaces = [1 2 3;4 5 6; 7 8 9;10 11 12]; %connect the vertices to the faces
patch('Vertices',PyramidVertices,'Faces',PyramidFaces,'FaceColor','g');
end
end
end
Example script:
% plotting a Objectorientated pyramid
%% Andreas Bernatzky 27.12.19
%%
clear all;
close all;
% define centerpoint
x = 0;
y = 0;
z = 0;
% define length
l = 7;
% define height
h = 5;
myPyramid = pyramid(x,y,z,l,h);
myPyramid.drawPyramid();
grid on
view(3);
I attached the files too.