While playing with fastprox and trying to layer it over a slope pigment, I get
the following error message: "cannot layer patterned textures"...
I thought that was the whole point of layering textures... What is happening?

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Mr schrieb:
> While playing with fastprox and trying to layer it over a slope pigment, I get
> the following error message: "cannot layer patterned textures"...
> I thought that was the whole point of layering textures... What is happening?

POV-Ray provides two ways of combining textures:

(1) Layered textures:

You create these by specifying multiple "texture{...}" statements in a row.

That's what you tried.

(2) Blended textures:

These include averaged textures (using "texture{average 
texture_map{...}}"), as well as patterned textures (using the 
"texture{PATTERN texture_map{...}}" or "texture{PATTERN texture{...} 
texture{...}}" syntax), plus a few specialties.

That's apparently what fastprox is using.


While blended textures can combine /any/ textures no matter how complex, 
layered textures can only combine simple "atomic" textures (and possibly 
other layered textures, though I'm not perfectly sure about this).

The reason for this is that layered textures are much more coherent, 
with the upper layers affecting the processing of lower layers (which by 
the way also allows for some optimizations), while the elements of 
blended textures can all be evaluated independently, and the results 
then just averaged according to the parameters in the combining texture.

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clipka schrieb:
> While blended textures can combine /any/ textures no matter how complex, 
> layered textures can only combine simple "atomic" textures (and possibly 
> other layered textures, though I'm not perfectly sure about this).

I just read your other post. To avoid any misunderstanding: Patterned 
/pigments/ (and patterned normals, for that matter) present no problems 
in layered textures. A texture can have the most complex pigment, and 
still qualify as a simple "atomic" texture.

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clipka <ano### [at] anonymousorg> wrote:
> clipka schrieb:
> > While blended textures can combine /any/ textures no matter how complex,
> > layered textures can only combine simple "atomic" textures (and possibly
> > other layered textures, though I'm not perfectly sure about this).
>
> I just read your other post. To avoid any misunderstanding: Patterned
> /pigments/ (and patterned normals, for that matter) present no problems
> in layered textures. A texture can have the most complex pigment, and
> still qualify as a simple "atomic" texture.

Thanks (sorry for double posting)I still have to identify excactly where the
problem is but what you said gives me a clue to a different approach using
black or white with blended textures instead of transmit with layered textures.
Yet I'm not sure it will work as I'm trying to use the back diffuse light which
i guess doesn't show without transparency, does it?

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Mr schrieb:
> Yet I'm not sure it will work as I'm trying to use the back diffuse light which
> i guess doesn't show without transparency, does it?

It does.

Transparency is really only needed to have things on the other side be 
plainly visible, unblurred.

Backside illumination is there to do exactly the opposite: Make an 
object appear translucent, /without/ making things on the other side 
plainly visible.

Note however that in order for backside diffuse illumination to do 
anything useful, your objects must be either non-solid (i.e. just one 
infinitely thin surface), or you must use radiosity for the light to 
carry all the way through the object.

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clipka <ano### [at] anonymousorg> wrote:
> Mr schrieb:
> > Yet I'm not sure it will work as I'm trying to use the back diffuse light which
> > i guess doesn't show without transparency, does it?
>
> It does.
>
> Transparency is really only needed to have things on the other side be
> plainly visible, unblurred.
>
> Backside illumination is there to do exactly the opposite: Make an
> object appear translucent, /without/ making things on the other side
> plainly visible.
>
> Note however that in order for backside diffuse illumination to do
> anything useful, your objects must be either non-solid (i.e. just one
> infinitely thin surface), or you must use radiosity for the light to
> carry all the way through the object.

I guess the problem was that I had a somewhat closed mesh (head open at the
neck). So I would have to use radiosity. Thanks.

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