How to change the visualization from lines to a patch

I have a robot maze that is in 2d and im trying to make it 3d. Currently the walls are lines and I need to turn them to patches but i'm not sure how to do this?

function [maze_figure, maze_axes] = drawMaze3d(maze)

    % prepare figure and axes
    maze_figure = figure;
    maze_axes = axes;
    axis equal;
    hold on;
    title('this will become the 3d maze')

    % set axis properties depending on maze size
    axis([0 maze.number_of_columns 0 maze.number_of_rows+2]);
    set(gca, 'xlim', [0 maze.number_of_columns], 'ylim', [2 maze.number_of_rows+2], 'xtick', [], 'ytick', []);
    set(gca, 'xtick', [], 'ytick', [], 'ztick', []);

    view(30, 30)
% ----------------------------------------------------------------------------------------------------------------------
% remove this line and specify camera properties of the maze_axes here for (b)
% ----------------------------------------------------------------------------------------------------------------------

    
    % draw the grid
    for i_col = 1:maze.number_of_columns
       for i_row = 1:maze.number_of_rows
            % draw the northern wall
            if maze.hasWall(i_row, i_col, 1)
                drawWallNorth(maze, i_row, i_col);
            end

            % draw the eastern wall
            if maze.hasWall(i_row, i_col, 2)
                drawWallEast(maze, i_row, i_col);
            end

            % draw the southern wall
            if maze.hasWall(i_row, i_col, 3)
                drawWallSouth(maze, i_row, i_col);
            end

            % draw the western wall
            if maze.hasWall(i_row, i_col, 4)
                drawWallWest(maze, i_row, i_col);
            end
       end
    end
end

% nested functions
function drawWallNorth(maze, row, column)
    x1 = column-1;
    x2 = column;
    y1 = maze.number_of_rows - row + 3;
    y2 = maze.number_of_rows - row + 3;
    plot([x1, x2], [y1, y2], 'k', 'linewidth', 4);
% ----------------------------------------------------------------------------------------------------------------------
% add a 3d patch here for (a)
% ----------------------------------------------------------------------------------------------------------------------
end
function drawWallEast(maze, row, column)
    x1 = column;
    x2 = column;
    y1 = maze.number_of_rows - row + 3;
    y2 = maze.number_of_rows - row + 2;
    plot([x1, x2], [y1, y2], 'k', 'linewidth', 4);
% ----------------------------------------------------------------------------------------------------------------------
% add a 3d patch here for (a)
% ----------------------------------------------------------------------------------------------------------------------
end
function drawWallSouth(maze, row, column)
    x1 = column-1;
    x2 = column;
    y1 = maze.number_of_rows - row + 2;
    y2 = maze.number_of_rows - row + 2;
    plot([x1, x2], [y1, y2], 'k', 'linewidth', 4);
% ----------------------------------------------------------------------------------------------------------------------
% add a 3d patch here for (a)
% ----------------------------------------------------------------------------------------------------------------------
end
function drawWallWest(maze, row, column)
    x1 = column-1;
    x2 = column-1;
    y1 = maze.number_of_rows - row + 3;
    y2 = maze.number_of_rows - row + 2;
    plot([x1, x2], [y1, y2], 'k', 'linewidth', 4);
% ----------------------------------------------------------------------------------------------------------------------
% add a 3d patch here for (a)
% ----------------------------------------------------------------------------------------------------------------------
end

Answer 1

[William Rose]

@Amanda,

To help me create the maze, I made the image below. It could be helpful to future maze makers.

Then I wrote a main program to create a maze and call the plotting function.

%my3dMaze.m     W. Rose 2022-12-01
%MY3DMAZE       Script to test function drawMaze3d.m.
%
%maze.hasWall = NxMx4 array specifying N,E,S,W edges of each maze cell.
clear
%  Define maze object
maze1.number_of_rows=3; maze1.number_of_columns=3;
maze1.hasWall=ones(maze1.number_of_rows,maze1.number_of_columns,4);
maze1.hasWall(:,:,1)=[1,1,1;0,1,0;0,0,0];  %north walls
maze1.hasWall(:,:,2)=[0,0,1;0,1,1;0,0,0];  %east walls
maze1.hasWall(:,:,3)=[0,0,0;0,1,0;1,1,1];  %south walls
maze1.hasWall(:,:,4)=[0,0,0;1,1,0;1,0,0];  %west walls
%Draw maze
drawMaze3d(maze1);

It makes the figure below.

The modified plotting function calls patch() instead of plot(). It is attached.

[William Rose]

Non-square maze example.

%  Define maze object
maze2.number_of_rows=4; maze2.number_of_columns=5;
maze2.hasWall=ones(maze2.number_of_rows,maze2.number_of_columns,4);
maze2.hasWall(:,:,1)=[1,1,1,1,1;0,1,0,0,0;0,0,1,0,0;0,0,0,1,0];  %north walls
maze2.hasWall(:,:,2)=[0,0,0,0,1;1,0,1,1,1;1,1,0,1,1;1,1,0,1,0];  %east walls
maze2.hasWall(:,:,3)=[0,0,0,0,0;0,0,0,0,0;0,0,0,0,0;1,1,1,1,1];  %south walls
maze2.hasWall(:,:,4)=[0,0,0,0,0;1,0,0,0,0;1,0,0,0,0;1,0,0,0,0];  %west walls
%Draw maze
drawMaze3d(maze2);

[Amanda]

i'm not sure where to put this in the code I gave above

[William Rose]

@Amanda,

The .m file I attached above is a modified version of your function. Compare it to your original function to see what I changed. They key change is to replace

plot([x1, x2], [y1, y2], 'k', 'linewidth', 4);

with

patch([x1,x2,x2,x1],[y1,y2,y2,y1],[0,0,1,1],'m'); 

inside the subfunctions drawWallNorth(), drawWallSouth(), etc.

The patch command above draws one wall panel: a rectangle whose top and bottom edges extend from (x1,y1) to (x2,y2), and whose top and bottom edges are at z=1 and z=0.

I also added a patch command to draw a gray floor at level z=0:

patch([0,maze.number_of_columns,maze.number_of_columns,0],...
    [2,2,maze.number_of_columns+2,maze.number_of_columns+2],...
    [0,0,0,0],[.7,.7,.7]);