POV-Ray : Newsgroups : povray.general : That normal question : That normal question Server Time
11 Aug 2024 09:20:33 EDT (-0400)
  That normal question  
From: Rune S  Johansen
Date: 13 Aug 1999 19:39:28
Message: <37b4acb0@news.povray.org>
I know I have brought this subject up before but
there have been some misunderstandings and I
didn't word my problem clearly enough.

This is my problem:

I have #declared a scg object made of multiple
objects each with different textures. These
textures contains normals of different kinds.

Now I want to use the object in a scene but the
object is way too large so I have to scale it
down 100 times.

But when I have scaled the object down this
problem appears:
All of the normals used in the object which is
of the kind that were not original meant to be
used in normals are now 100 times too deep
(e.g. it looks like bozo 200 instead of bozo 2).

I have made an example to show what I mean.
Change the value "Scale" to high and low values
like 100 and 0.01.
Although the camera, the light_source, and the
#declared object are all scaled by the same
amount you will see that the normal changes.

// Start of example

#declare Scale = 1;

camera {
   location -3*z
   look_at 0
   scale Scale
}

light_source {<10,20,-30>*Scale, color 1}

#declare Sphere =
sphere {
   0, 1
   pigment {color rgb 1}
   normal {bozo 1 scale 0.2}
}

object {Sphere scale Scale}

// End of example

So here's my questions:

Is it a bug? (If it isn't I think it is very
confusing and annoying).

If it isn't a bug how can I come around it
without having to change the object itself?
Because it is not always possible to change the
object for example in include files where
objects are used in multiple scenes.

I'm writing this because I have so far come
across the problem quite a lot of times and it
often blocks me from getting on with the project.
So I hope you can help me!

Greetings,

Rune S. Johansen

---
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