It looks good janbo!
That said, i would precompute the blurred levels for the PBR shader myself....You can see cubemap edges on those spheres too ..(squares in the reflection where the edges of the cubemap are). Might be worth limiting the lookup values a bit so its not sample edges - i ahd a similar problem when I started using mipmapped cubemaps and had to force sampling at the top level with a bias value.
The PBR demo that ships with studio runs very fast (>2400fps on my pc) and so it is quite impressive. It was that speed that I was after as well as a really nice look. The pre-rendered and filtered lightmap and reflection maps are a quick lookup for each pixel in the final render so its a smart way to render quickly. Thats the way to get fast results rather then actually smoothing/bluring in the shader during every render.
The only reason why I was asking about the 8 levels of precomputed images was that I wanted to know how to conserve radiance energy and make the pre-computed levels realistic with a true BRDF solution. My filter shader works but im still not sure its working right. The maths is horrendous and following it is now hurting my brain!
Its taken me an age to find out how to render ambient occlusion and then store that into the normal map texture too. Ive been messing with my 3d editing software for over an hour now baking textures. One texture that the AppGameKit PBR shader stores the normal map (RG), ambient occlusions(B) and the roughness(A) and so i had to code up a quick bit of software to blend separate images into one. I then need to convert each from a HDRI into a PNG with exponent in the a channel.
This is not my model!....I cant take any credit for that. Im just loading it and rendering PBR shaders on it.
Its made up of 9 different textures for reflections and lightmaps and honestly is a nightmare to rebake them all. It has 4 different reflection maps which all have 8 levels of filtering. Im still using the equirectangular light maps and reflectance maps.
One of the issues i was talking about is shown in the background....you can see bands of colours and that is due to using LDR images in a skysphere lightmap so I am using HDR radiance maps in the object shader as thats what the AppGameKit PBR shader requires anyway and it gets away from the prolems that creates.
The original maps used in the pbr example are properly rendered BRDF based filters and are done in HDR in the png images vs just a 8bit per colour standard texture. It took me a while to understand how that works but its really quite simple and easy to implement too. Thats a case of writing a pack function to complement the "unpack" function used in the shaders. Im glad I finally managed to find that out. The HDR Radiance maps work best for really good reflections.
I was struggling with what filtering to use to do it properly but there are a load of good resources of how to do correct perspective corrected BDRF cook torrence filtering and other correct rendering of reflectance maps and light maps. I wish id never looked into it...lol
Honestly im getting a bit tired of it now. Suffering from fried brain syndrome with this.