lambertian reflection from sphere in matlab

main.m
% Sphere parameters
center = [0 0 0];
radius = 1;
material_color = [0.8 0.2 0.2]; % Red sphere
k_diffuse = 0.7; % Diffuse reflection coefficient

% Light source parameters
light_position = [1 1 1];
light_intensity = 0.8;
light_color = [1 1 1];

% Create a grid of points on the sphere's surface
[X,Y,Z] = sphere(32);
X = X * radius + center(1);
Y = Y * radius + center(2);
Z = Z * radius + center(3);

% Calculate the normal vector at each point on the sphere's surface
N = [X(:) - center(1), Y(:) - center(2), Z(:) - center(3)];
N = bsxfun(@rdivide, N, sqrt(sum(N.^2, 2)));

% Calculate the direction vector from each surface point to the light source
L = bsxfun(@minus, light_position, [X(:) Y(:) Z(:)]);
L = bsxfun(@rdivide, L, sqrt(sum(L.^2, 2)));

% Compute the diffuse reflection coefficient using the dot product of the normal vector and the light direction vector
D = k_diffuse * max(0, dot(N, L, 2));

% Calculate the color of each pixel on the sphere's surface
color = bsxfun(@times, material_color, D) * light_intensity .* light_color;
color = reshape(color, size(X));

% Visualize the result
surf(X,Y,Z,color);
axis equal;
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