@Erik:

> They are read from the ambient, diffuse and specular files in
> fgdata/Lighting. For the default lighting scheme these do get altered,
> but I think you already override that scheme completely.

Um... as they depend on the sun angle, these appear to be the light intensity 
curves. I indeed override those. I'm interested in the reflection coefficients, 
which must be part of the materials definition - I know that for some 
landclasses diffuse and specular are explicitly defined, but I don't know what 
the defaults are otherwise.

But I guess I found a viable solution yesterday.

@Fred:

> I presume the balance between ambient and diffuse should vary with the  
> weather. A clear sky gives harsh shadows and overcast sky with several  
> layers of clouds gives barely any shadows (dull day in photographer  
> speak). Your results (which are really pretty) are likely to be  
> unrealistic with bad weather and perhaps a middle term as it is now will  
> fit more situations if the balance is not adjustable.

Luckily for me Advanced Weather already comes with a model how light intensity 
is changed by the cloud cover and the interface to the shader is already in 
place and being used to reduce diffuse light under strong cloud cover ;-) So 
that's solved already -  to quote myself "3 lines in the shader including all 
the environment dependencies on cloud cover and sun angle" (it doesn't do to 
reduce ambient light before sunrise for instance) - for moderate cloud cover, 
the effect goes back to what you're used to, for strong cloud cover diffuse and 
specular light pretty much go away. 

I think the actual effect is pretty much perception - the ambient light doesn't 
go away that much in clear skies, but the eye, having the contrast to surfaces 
illuminated by high intensity light, reduces shades surface to dark. So we 
could attack this also by simulating real light intensities and do perception 
reweighting later as well, but just reducing ambient light to make up for 
actual high diffuse intensity seems to do the trick nicely.

@Stuart:

> Given that we've got a very limited number of tree textures and the
> same texture is used on a large number of objects, perhaps it would be
> worthwhile increasing the resolution?

The regional Caribbean palm trees should have a higher resolution if anyone 
wants to have a look at the differences. We seem to have some forum users who 
are sort of committed to provide more variety and higher resolution tree 
textures which we can encourage.

Personally I would like to have higher resolution trees after spending quite a 
lot of shader lines for terrain close-up rendering - but I have a lot of memory 
to spare, and I understand the argument that for many users trees will be 
something seen from a few hundred meters at best.

* Thorsten


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