Nathan,

I have play with your scene. Good job (as usual)!!

> --------------- THE BUGFIX ----------------
> 
> There are two objects in this scene.  The one on the left is a height field
> created from a granite pattern.  The one on the right is a flat box with a
> granite normal applied.
> 
> The variable Size at the top sets the overall size of the scene.  All
> objects are relative and changing Size will scale everything relatively.
> So, if you change Size you should expect the scene to look exactly the same.
> (This is my basic assumption, so if this is incorrect, please let me know!)
> 
> Now, the depth of the bumps of the height field will automatically follow
> this assumption.  If you scale it twice as big, it gets twice as big in all
> three directions: x,z, and y(which is the depth).
> 
> The goal of my changes in MegaPov is to make the surface normals mimic the
> actions of the height field.  When rendered with MegaPov, both the flat
> object with normals and the height field should look very similar and behave
> the same way when Size is changed.
> 
> If this is rendered in official POV-Ray (with the height-field commented
> out), then changing Size will not leave you with the same scene.  Scaling it
> larger will leave you with a very flat box, while scaling it smaller will
> leave you with huge fake bumps.
> 
> You can change the Depth variable, too.  The Depth variable scales the box
> and height field along the Y axis, effectively changing the depth of the
> bumps.  The height field and box should remain looking similar as Depth is
> changed.  This has a limited range over which it looks believable, of
> course, since the normal IS faked on the box.
> 

I think this is the correct behavior!!
And your scene show that this is good!
Ok with this Nieminen Juha?

> --------------- THE BUG ----------------
> Did you notice the line #declare ShowBug=false; at the top?  If you set that
> to true, the normals on the box will look horrible.  That is because of a
> bug which I am aware of.  The problem is the "scale".  It's a complicated
> explanation.  If you really care, look at my most recent post in the
> bugreports group.

I think that this is a bug and must be corrected
Ok with this Nieminen Juha?

> 
> Anyway, MegaPov does fix a real bug that was really giving the wrong result,
> but also introduced a new very bad bug that also causes it to give the wrong
> result.
> 
> -Nathan
> 

Go on Nathan! I think all will be ok quickly :)!

Fabian.

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