how to create a transparent sphere

I have created a sphere using the [x,y,z} = sphere() function however, when I go to use alpha(.15) to try and add some transparency it just keeps giving me a dark sphere... I also tried using the following code;

[x,y,z] = sphere(128); colormap(hot(256)); shl = surfl(2*x,2*y,2*z); hold on; sh2 = surfl(2*x, y, 2*z); alpha(shl,.15) shading interp;

but this simply gives me two spheres one that is a block colour inside a larger transparent sphere. Any idea what the issue is

Many thanks

Answer 1

[Thorsten]

[x y z] = sphere(128);
h = surfl(x, y, z); 
set(h, 'FaceAlpha', 0.5)
shading interp

[Bran]

Hi there do I use this along with the sphere() function?

[Thorsten]

Yes. I added the code to my example.

[Bran]

Thanks so much Thorsten

[Bran]

Hi thorsten, I have come across an extension to this original problem. Instead of using x y and z to trace my sphere I would like to use values stored in a vector which have been sampled in the sphere and have retained this shape. However, I only have the indices of these values so my question is two-fold. How can I do the reverse of what is usual and that is find the value at particular indices rather than the other way around? And also how can I then use these values to trace out my transparent sphere?

Many many thanks for all your help :)