Add a few Post Processing effects

[shadowmage45]

Would be nice, for my own personal tastes, to have the following available:

Must-Have:

• Bloom - needs cameras switched to HDR. This is really the 'big one' that makes metallics/PBR rendering notable.

  Would be nice:

• Motion Blur - combined with bloom you get a much more cinematic effect.
• Depth-of-field - undecided on this one as well. Mostly would be PITA to get it working with the multi-camera setup.

Can use shaders from Unity PostProcess stack, with modifications to remove bloat for unused features (e.g. bloom doesn't need auto-exposure texture if auto-expose is not used).

Replacement For Scatterer:

https://assetstore.unity.com/packages/essentials/the-blacksmith-atmospheric-scattering-39939 https://github.com/SlightlyMad/AtmosphericScattering https://forum.unity.com/threads/screen-space-multiple-scattering.446647/ https://github.com/kode80/kode80CloudsUnity3D https://www.alanzucconi.com/2017/10/10/atmospheric-scattering-1/ http://www-ljk.imag.fr/Publications/Basilic/com.lmc.publi.PUBLI_Article@11e7cdda2f7_f64b69/article.pdf https://atomworld.wordpress.com/2014/12/22/flexible-physical-accurate-atmosphere-scattering-part-1/ https://atomsdev.wordpress.com/tools/unity3d/as3-atmosphere-scattering-simulation-solution/ https://ebruneton.github.io/precomputed_atmospheric_scattering/ http://www.cosmic-ray.org/users/reid/thesis/node5.html https://www.gamasutra.com/blogs/BartlomiejWronski/20141208/226295/Atmospheric_scattering_and_volumetric_fog_algorithm__part_1.php

world-space view direction in image effect

REMEMBER TO NORMALIZE THE INTERPOLATED VIEW DIRECTION VECTOR

• The vert shader sends a linearly interpolated normal, which has valid ratios but of non unit-length
• The frag shader expects a unit-vector for direction

https://forum.unity.com/threads/problem-with-using-a-cubemap-in-an-image-effect.122511/ https://forum.unity.com/threads/help-with-view-space-normals.454248/ https://forum.unity.com/threads/image-effect-ray-trace-sampling-problems.237793/

Runtime manual cubemap capture - blit then copy

https://forum.unity.com/threads/problem-with-graphic-blit-and-cubemaps.483354/#post-3818005

Random link to some real-time reflection probe updating with post-processing

https://github.com/LightStriker/ReflectorProbe