Viz antialias

[chrisdembia]

Tested on OSX and Linux. The other view buttons still work.

The saved images are not antialiased. I tried to insert the glEnable(GL_MULTISAMPLE) into different places to try and get antialiased images, but I couldn't get it to work. Any ideas?

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This change is 

[sherm1]

Any thoughts on this @peastman? Chris enabled antialiasing for the visualizer and it works fine but the images that are saved to files aren't antialiased.

[sherm1]

Chris, I tried this on Windows and could see any difference between antialiasing on or off. Same result on Windows and on my Ubuntu VM. Possibly I don't know what to look for. I tried the Simbody "Rattleback" example which has an ellipsoid. Do you have a better test case?

[chrisdembia]

Thanks for testing. I presume you mean "Same result on OSX and on my Ubuntu VM." I've noticed the effect with ellipsoids, but for this PR I was looking at TaskSpaceControl-Atlas. Even with antialiasing, there is still some aliasing but it should definitely look better.

There is an OpenGL parameter to increase the number of samples in the multisampling.

[sherm1]

I presume you mean "Same result on OSX and on my Ubuntu VM."

No, I'm not running OSX. It is Windows 8.1.

[sherm1]

This might provide some info on how to get antialiasing working for saved images and movies: http://stackoverflow.com/questions/20482851/how-to-use-multisampling-with-opengl-fbos

The visualizer makes its own frame buffer to render those into; that also has to be created multisampled.

[chrisdembia]

Thanks @sherm1 for that link. I quickly tried to do what they said but then the saved images came out as black. I'd prefer to merge this without anti-aliased images. We can revisit the anti-aliasing of images later.

Could you send me screenshots of the visualizer on your computer with/without anti-aliasing?

[sherm1]

Antialiasing off:

Antialiasing on (or at least I selected it):

I don't see any difference between them.

[chrisdembia]

Yeah antialiasing isn't working there in your screenshots. Here's on OSX:

without antialiasing:

with antialiasing:

Focus on the upper edge of the ground.