brainpolka wrote:I need all the help I can get, so please do tell more
Anyway, I don't really like the physsky in Kray that much and I thought the HDRi looked better.
I wish it had more options etc. etc.
So I tell you more:
- Photon Map receiving by this source of light is very "dirty". Give a lot of "Hot Photons" which are difficult to smooth or reduce. It can affect light leaks, different colors in regions which should be at all.
- strong reflection which source of that is strong light information is some parts of HDRi image. This affect no accurate reflection (yes!) and combine with not accurate light because user increasing power of light from HDRi to bright up scene create not balanced light. Situation force users to tweak surfaces and going away from accuracy.
- No direct light from HDRi force user to add physical light to scene which mix all ideas of accuracy.
- The reason why people use HDRi in Exteriors is perhaps the natural light which HDRi offer WHICH is NOT in my opinion. It gives only illusion created by clouds and Sun which we see in image. But light and color information is very disordered and solution for that is to BLUR this map.
- HDRi map CAN NOT offer you direct light! There is some ideas to add physical light in place where is Sun automatically by scanning HDRi image and finding place with the stronger light information (in this situation will be averaged place of Sun in HDRi image)
- HDRi also has light information from ground part of image. Tweaking power of HDRi also you raise up power of light coming for example from grass in HDRi. It affect sometimes strange colors in render. You can desaturate HDRi of course but I you noticed it`s starting be wasting time (control power, blur, desaturate, surfacing tweaking)
Physky light for example Kray Physky is exactly the same idea as HDRi! but:
- it offer accurate and balanced light which give to us also Direct Light (Sun)
- Photons coming from Physky are "clean"
- Physky is create according to real atmospheric behaviour.
- Physky offer faster render because photon map created but this are much more cleaner. Final Gathering, QMC are just faster.
- Physky offer better control (yes!) and still photon map achieving by this source of light is clean.
- Do not worry about clinic light which offer Physky. Important in render are balance light and color close to real light. In my opinion is easier make post process after Physky then HDRi.
- it offer no control because is done according to physic (of course we can raise up power or turbidity but I think best idea is not touch those functions especially in future in Physky2)
- you can turn OFF direct Sun from physky and use this as ambient environment light!
Summary:
Physky2 in Kray3 (
http://cgg.mff.cuni.cz/projects/SkylightModelling/) Will offer us great opportunity which we never had before. It working very well in Podium for Google Sketchup where people working now with Kray3 engine. It will be activated soon for LW (in a couple day I will receive next test K3 where Physky2 will be activated)
If is there something wrong or questions on this very difficult topic pleas ask or correct me.
Personally I do not use HDRi at all....
I know how hard is deal with plants. The biggest problem is not with exterior as everybody thinks, but with plants. It is so difficult render grass, leafs, trees , etc because they are full of physics (SSS, transparency, reflections, bumps, different diffuse) ...in my opinion this is very, very difficult part of renders and personally it get me Crazy! Also are some limits in Kray (not big deal but they are). The house looks very good. Clouds I would change for better quality and more blue Sky.
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