[vtk-developers] Re: [Paraview-developers] [LONG] Antialiasing with multisampling method

[David C. Thompson]

> Here is my question. There are a couple of ways to make the regression tests
> not to fail because of multisampling.
> 
> 1. Remove multisampling query: we will never get a multisample context, but
> users may like to have antialiasing anyway.
> 2. Once we get a multisample context, call glDisable(GL_MULTISAMPLE) and never
> use multisampling. We potentially get a context with a special buffer that
> allocate some video memory for nothing, when this memory could be useful to
> load a lot of textures.
> 3. Set default value of GlobalMaximumNumberOfMultiSamples to 0 instead of 8.
> 4. Set default value of MultiSamples to 0 instead of
>    GlobalMaximumNumberOfMultiSamples.
> 5. On each potentially failing test, call SetMultiSamples(0) at the beginning,
> which requires access to the concrete type of RenderWindow.
> ... Solution 5 looks easy for VTK tests, less easy for ParaView tests.
> 
> Any opinion about thoses solution, or some alternate solution is welcome.

Couldn't vtkTesting::RegressionTest() call SetMultiSamples(0) if
necessary before rendering? For ParaView, couldn't the same thing be
accomplished inside GUI/Testing/Tcl/Compare.tcl? I supposed that if a
test required MultiSamples turned on, it would have to explicitly
request it of vtkTesting or Compare, but I suspect this would be many
fewer tests than the other way around.

	David