PNG alpha rendered as black in Blender

Question

I'm a Blender novice, so this is probably easy to fix.

When I use a transparent PNG as a texture in Blender, the parts that should be transparent are rendered as black.

This is especially confusing since in the material preview it looks as if the material would indeed be transparent.

Here's a screenshot:

This is the test texture, and in the right on top of a checkerboard:

                      

Here is the .blend file in case you want to check it:

                                                     

Edit: After playing with the settings, it does render with transparency in the rendered output, but that's not what I need. I want to use the models with Three.js, so I want to just quickly see how it looks in Blender, I don't need more than simple "Z-transparency" ("regular" one, non-raytraced) here's a reference rendering of what I expect to see in Blender while I edit (this is the same model rendered with Three.js on an HTML <canvas>):

                                               

Solution

Just in case none of the two nice fellow at BlenderArtists chose to answer here, here's the two possible ways to do it:

SxJP's answer:

In the viewport, click N, open the "Display" tab and under "Shading", select "GLSL".
Click the link above for the original post.

                                    

Sanctuary's answer:

This one allows you not having to use the GLSL renderer. To avoid duplication, click the link to go to the answer, it has handy screenshots.

                                    

Comments

[Camilo Martin]

I'm wondering if Blender just isn't capable of showing a transparent texture on the editing panel. I hope this is not the case.

[Ignacio Vazquez-Abrams]

Is it a PNG8 or a PNG24?

[Camilo Martin]

@IgnacioVazquez-Abrams It is the image I've posted here, so yes, it is PNG32 (remember, PNGs with transparency have 32 bits per pixel... 8R+8G+8B+8A)

[Camilo Martin]

Note to possible answerers: I've found the answer, a guy at BlenderArtists just posted it. If he choses to post it here, I'll choose his answer. If not, I'll post it myself and choose it. The answer is in this link.

[Camilo Martin]

Actually, now two guys posted answers there, how timely with my bounty here, lol.

[Derek 朕會功夫]

@CamiloMartin - How did you make the I'm actually a .zip file thing?

[Camilo Martin]

@Derek朕會功夫 - Cool isn't it? :D cat file.png file.zip > mix.png on Unix, and copy /B file.png file.zip mix.png on Windows. This works because 7-Zip (and many other programs) will look for the zip header (or any other valid header that it supports), even if it's not at the beginning. For this reason you can open .docx, installers, and a number of proprietary-format files straight in 7-Zip. The image itself was self-made.

[Derek 朕會功夫]

@CamiloMartin - Thanks for the explanation! I'm sure this will be useful for me some time in the future.

[Camilo Martin]

Glad I could help @Derek ^^

[Camilo Martin]

Oh, and by the way, the image is public domain, in case you want it you're free to use it too. Here it is, ready to be concatenated with whatever zip: i.imgur.com/1cHoKa4.png

[Derek 朕會功夫]

@CamiloMartin - Actually I came here because I encountered a similar problem as yours. Is there any chance you can take a look at my problem: superuser.com/questions/610327/… Thanks! (I had the exact opposite situation as yours, black in rendered, transparent in viewport, weird)

[Camilo Martin]

@Derek Sorry, wish I could help really, but since this question one year ago, I didn't use Blender at all, and I'm still a complete n00b :(