Lux snow shader for unity 5 [beta 22]

hi there,
just a first preview on the upcoming snow shader for unity 5.
right now it supports dynamic accumulation based on an adjustable snow direction, snow erosion, melting and drying.

update: shader is online now and works with unity beta 22.
get it from my github repo:
https://github.com/larsbertram69/Lux_2.0/


feedback is welcome ;-)

thanks,
lars

melting snow




melting snow using the erosion feature

 

as usual, pretty cool lars.
edit : Just curious, what the plan for lux terrain shader? would be cool if there's a variant between standard terrain, wet terrain, and snow

 

thanks rea!
as far as the terrain shaders are concerned: beta 21 brought a lot of changes and i will see, what unity might come up with.
terrain shader solutions usually are a lot of work – so i might just update my color map ultra shader package...
but we will see.

lars

 

as always... epic.

 

@lars - What maps/tex do your Unity5 terrain shaders need? I love the wet/puddle shader and the snow build-up shader, but would like to know how easy they are to implement over and above the needs of the basic Unity5 standard terrain shaders.

 

the snow shaders currently are no terrain shaders but shaders for custom geometry. next to diffuse, normal and smoothness ( spec is hardcoded as dieletric at the moment) they need height and ao. snow (diffuse, normal, smoothness and micro distribution) are global maps.

 

Thank to you. Is very good work. Waiting this system in AssetStore.

 

hi there,
i have updated the shader to work with unity 5 beta 22 and pushed its initial version online.
i have also added some more sophisticated functions for snow accumulation and adjusted the setup script so in case you also use the wetness shaders – you will have to update those too.

get it from my github repo:
https://github.com/larsbertram69/Lux_2.0/


snow accumulation now supports a growing amount of snow flakes:

 

hi there,

during the last 2 days i have been looking into adding decals to the snow shader in order to create much more lively environments.

and as i wanted the decals to blend smoothly with the base surface (using alpha blending) without having to use forward rendering – while the camera would use the new deferred rendering pass – i worked on a "deferred decal snow shader" that supports alpha blending while still being rendered using the deferred rendering pass.
so finally i came up with a (cg only) shader that does all this: it uses alpha blending (giving you nicely fading borders) while still being rendered using the deferred pipeline.

finally i have tested it using dantus’ outstanding decal framework – and it works just fine!
with a bit more of investigation i will probably not even have to use some hacky "alpha blending in deferred" but can simply use "alpha testing" and still get absolutely smoothly fading decals due to dantus’ superior framework (which lets you "steal" uvs from the underlaying geometry).

snow decals are fully dynamically and react to all changes you make to the values of "snow amount" or "snow melting".

so this it what you might archive:

 

btw. did you see this post about decals? (with sample project included)
http://blogs.unity3d.com/2015/02/06/extending-unity-5-rendering-pipeline-command-buffers/

 

yes i did.
but those decals do not suite our needs: no ambient lighting, no ambient reflections, no GI – no lightmapping.
so at their current state they will most likely never fit a given environment in case you use any of the features mentioned above (and you should use a bunch of it!).
for this reason i have chosen to render "real" geometry in the regular pipeline that might take advantage of everything unity 5 has to offer.

lars

 

hi there,
as a video will most likely give you a much better idea about snow decals, here we go.
all this would not be fancy at all – if it was not deferred only ;-)

 

I am working on something very similar at the moment and are stuck with the same problem on decals.
Your version looks pretty good but I wonder how it works exactly. Are you able to blend the normals as well or are they "clipped"?
I was able to have alpha tested normals and blended albedo value.

But what I want is a way to blend each channel by the alpha value (Albedo, Normals, Metallic, Emission...).
Did you fix any of that in your shader?

 

hi there,
shader blends all gbuffers – which works fine for albedo (rt0) and normals (rt2):
rt0 stores occlusion in the alpha channel which currently is not used anywhere as far as i can say.
alpha of normals (rt2) is unused too.
metallic does not exist: it is specular color (rgb) and smoothness (a) – and as smoothness is stored in alpha of rt1 using alpha blending leads to some problems here...
emission (storing ambient diffuse and specular reflections in rt3) is ok as alpha is unused as far as i can say.

 

And thanks for making me having another look into the different gbuffers which helped me fix a huge bug...

 

I may be totally wrong – but right now i have the strong impression that the standard shaders just burn your gpu without any need in deferred: http://forum.unity3d.com/threads/is-unitys-new-standard-shader-inefficient-in-deferred.296759/

lars

 

and here is the latest preview:

 

Great work, Im impressed with your shader, and believe me, Im rarely impressed

 

After my post I have been working on this and came up with a decal which blends all channels, yay!
But it seemed that the reflections where gone and I assumed that they are in the emission map.
Now I read your post:

Do I have to choose another Camera Event where reflections haven't been calculated?
Or are reflections not calculated in screen space?

 

well, i would like to have deferred ambient diffuse and reflections too – but they are calculated while filling the gbuffer.
may be doing it this way made it easier to blend between light and reflection probes… but it is not most efficient, i think.

 

At least that explains something. I was always wondering why only the standard shader has reflections.
Maybe there can be an option for "UseLightProbes or DynamicGI" and if not then skydome reflection is calculated in screen space?

 

dynamic gi comes from lightmaps. so its always per object and has to be written to the gbuffer.
light and reflection probes could be added in the final deferred lighting pass – if they were deferred and culled like lights i guess.