Chris Huff <chr### [at] maccom> wrote:

> In article <3aad1701@news.povray.org>, Geoff Wedig 
> <wed### [at] darwinepbicwruedu> wrote:

>> I didn't think it would. I only added it because it kept saying "Normal 
>> type not defined"

> Because you were specifying a float value when it expected a normal 
> pattern or normal identifier.


>> I know.  I was trying to take a pigment I made with a proximity and 
>> use it in the normal instead.  I knew I'd have to jiggle the 
>> variables, but since it didn't work at all...

> Well, of course it didn't...you have to do more than "jiggle the 
> variables", you have to use a completely different type. Don't expect to 
> be able to use an object as a color, either.

It was a mistake on my part, because I (stupidly) assumed that a normal
takes a normal_map.  I don't know why I thought that, since a pigment
doesn't take a pigment_map, nor a texture a texture_map, but I did.  Mea
Culpa.


>> In fact, this is the problem.  When I changed to a slope map, it worked. 
>> didn't do what I wanted,

> I would be surprised if it did...you are still using the wrong type. The 
> slope_map takes a 2D vector...when you specify a float, the same value 
> is used for both components when it is automatically promoted to a 2D 
> vector, for example, 0.5 is promoted to < 0.5, 0.5>...which is pretty 
> much useless in slope_maps.

No, when I changed to slope map, I changed the components too.  I know that
the type would be upgraded, and at least I'd be able to see the areas where
things were happening, and could tweak later, but I didn't do that.

 The first component is "height", and the 
> second is "slope". POV uses a spline based on this information to figure 
> out the slope of the pattern at in-between values, and get an equivalent 
> to a "color_map" for normals. A normal_map behaves more like a 
> pigment_map than a color_map, it interpolates between complete normals, 
> each with it's own pattern and other normal stuff.
> If you stated what your goal is, you might better help...however, I 
> suggest you look through the manual, which clearly explains the syntax 
> of normals, normal_maps, and slope_maps...especially look at section 
> 2.7.2, which is a tutorial about normals, and section 4.7.2, which is a 
> complete syntax reference for normals.

I'm pretty familiar with this stuff, really.  I just had a brain loss for a
bit there.  Sometimes the simplest things seem to disappear.

As I see it, the error should have come up in the normal_map, though, not at
the end of the normal.  That's where there were missing types, it seems,
since a normal can consist of a normal_map of normals.  It was specified
correctly, but the normal_map wasn't.  Again, it was a stupid error, but the
error message was a little esoteric.

>> but it didn't crash. ;)

> Wait, it crashed before? That's not good, it means there is a bug 
> somewhere...it should just stop parsing and produce an error message.

Sorry again.  Crashed in the euphamistic sense of "didn't draw a picture of
stunning complexity and beauty."  Of course, by that definition, POVray
always crashes for me. :/

Geoff

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