[x,y]=meshgrid(1:10,1:10);
z = peaks(size(x,1));
V = [x(:),y(:),z(:)];
F = delaunay(x,y);

trisurf(F, V(:,1),V(:,2),V(:,3))
http://www.alecjacobson.com/weblog/media/matlab-plot-3d-mesh-without-vertex-labels.png

indices = 1:size(V,1);
text(V(:,1),V(:,2),V(:,3),num2str(indices'))
http://www.alecjacobson.com/weblog/media/matlab-plot-3d-mesh-with-vertex-labels.png

text(V(:,1),V(:,2),V(:,3),num2str(indices'),'FontWeight','Bold')
http://www.alecjacobson.com/weblog/media/matlab-plot-3d-mesh-with-vertex-labels-bold.png

text(V(:,1),V(:,2),V(:,3),[repmat(' ',size(indices',1),1) num2str(indices')],'FontWeight','Bold')
http://www.alecjacobson.com/weblog/media/matlab-plot-3d-mesh-with-vertex-labels-bold-indented.png

figure
surf(peaks)
colorbar

https://www.mathworks.com/help/examples/graphics/AddColorbarToGraphExample_01.png