MSAA and Scene anti aliasing

[Kevin Rushforth]

I don't really like the single enum approach. I would prefer to keep the 
existing MSAA boolean, and then, if needed, add a separate attribute for 
requesting the number of samples; if desired there could be a read-only 
attribute that returns the actual number of samples used. Most chipsets 
give limited (or no) control over the number of samples anyway so an 
enum doesn't seem like a good fit.

-- Kevin


Gerrit Grunwald wrote:
> +1 for the enum approach...will make it easier to enhance for future options...
>
> Gerrit 
>
> Am 12.07.2013 um 19:55 schrieb Richard Bair <richard.bair at oracle.com>:
>
>   
>> Thor recently pushed an implementation for MSAA for those cases when the feature is supported by the card and where a Scene (or SubScene) is created with the antiAliasing flag set to true. MSAA is "Multi-sampled Anti Aliasing", which means that the graphics card, when configured in this mode, will sample each fragment multiple times. The upshot is that 3D doesn't look as jaggy.
>>
>> However this has an impact on performance (usually an extra buffer copy or at the very least you will be sampling each pixel multiple times so if you are doing something graphically intense then that might push you over the edge where you start to see performance degradation). Now multi-sampling can be 2x, 4x, etc. The higher the multi-sampling value, the better the quality, and the lower the performance.
>>
>> I'm also bothered but the name "antiAliasing" because there are many forms of anti-aliasing in the world and it isn't clear which this is. I think perhaps we should instead have an enum. The idea is that we can add to the enum over time with greater options for how to perform the scene antialiasing.
>>
>> public enum SceneAntiAliasing {
>>    DISABLED,
>>    DEFAULT,
>>    MSAA_2X,
>>    MSAA_4X
>> }
>>
>> And then grow it over time to include potentially other techniques. My thought here is that the implementation is going to matter to folks. They're going to want to be able to make the performance / quality tradeoff, and perhaps even the implementation tradeoff (since different implementations may provide somewhat different results). DISABLED turns it off, obviously. DEFAULT allows us to pick what we think is the best (might be different on different platforms. Desktop might go with MSAA_16x or equivalent while iOS might be MSAA_2X). Then some standard options.
>>
>> Thoughts?
>> Richard
>>