Reactor wrote:

> The issue arises when you transform an object
> with the aoi pattern - it has a tendency to transform the provided aoi vector,

Or rather *not* to transform the aoi vector, while you expect
it to move with the object? At first glance, it looks like the
transforms are only used to warp the point at which the texture
will be evaluated, parameters of the texture are not adapted.
I just tried a "slope y" texture, apply this to an object
and rotate it and the slope reference will still be y.

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Christian Froeschlin <chr### [at] chrfrde> wrote:
> Or rather *not* to transform the aoi vector, while you expect
> it to move with the object? At first glance, it looks like the
> transforms are only used to warp the point at which the texture
> will be evaluated, parameters of the texture are not adapted.
> I just tried a "slope y" texture, apply this to an object
> and rotate it and the slope reference will still be y.

Both may be the way you'd need it at times. Maybe even for the very same object
& pattern: In an object assembled from smaller building blocks, it may be
desired to orient the aoi pattern of all building blocks with reference to the
object, while when orienting the object those patterns should re-orient
accordingly.

Best thing would be if the reference point of an aoi pattern could somehow be
attached itself to a particular object... well, maybe that's something to
remember for next generation SDL.

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Christian Froeschlin <chr### [at] chrfrde> wrote:
> I just tried a "slope y" texture, apply this to an object
> and rotate it and the slope reference will still be y.

Actually, that's good news (for me at least). For some reason I imagined the
slope pattern would rotate around together with the object, so I went to great
length to make sure I got a uniform slope direction for a bunch of objects I
needed to rotate.
Now I can do some things in a different way.

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clipka wrote:

> Actually, that's good news (for me at least). For some reason I imagined the
> slope pattern would rotate around together with the object

yes, that's what I'd have still imagined yesterday, too ;)

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Christian Froeschlin <chr### [at] chrfrde> wrote:
> The MegaPOV examples scene pat_aoi.pov rendered in my patched 3.7b31
>
> It's not 100% identical to the MegaPOV render but that was to
> be expected for a radiosity scene. Without radiosity I did not
> see any difference.
>
> If anyone has some made some nifty trick using the aoi
> pattern and wishes to provide the scene file I'd be happy
> to test whether it works.

I've used it to vary the blurriness of reflectivity based on the viewing angle,
so using aoi for the micronormals (this example is a bit contrived, but shows
the effect I want):

// Render at 640x480 with AA set waaay up high
#version unofficial MegaPov 1.21;

camera { perspective location <1,0.67,-4> angle 45 look_at <0,1,0> }
light_source { <200,180,-200> rgb 1 }
plane { <0,1,0>, 0 pigment { checker rgb 1 rgb 0 } }

#declare normal_scale = 0.0001;
#declare blur_size = 0.08;

sphere {
 <0.0, 0.0, 0.0>, 1
 translate y*1

 pigment { rgb <1,0.1,0.7> }
 finish { reflection {0, 1 fresnel on} metallic }
 normal {
  aoi
  normal_map {
   [ 0.00, bumps blur_size*1.00 scale normal_scale ]
   [ 0.05, bumps blur_size*0.99 scale normal_scale ]
   [ 0.10, bumps blur_size*0.98 scale normal_scale ]
   [ 0.15, bumps blur_size*0.96 scale normal_scale ]
   [ 0.20, bumps blur_size*0.92 scale normal_scale ]
   [ 0.25, bumps blur_size*0.87 scale normal_scale ]
   [ 0.30, bumps blur_size*0.80 scale normal_scale ]
   [ 0.35, bumps blur_size*0.70 scale normal_scale ]
   [ 0.40, bumps blur_size*0.56 scale normal_scale ]
   [ 0.45, bumps blur_size*0.34 scale normal_scale ]
   [ 0.50, bumps 0 ]
  }
 }
 interior { ior 2.2 }
}

// Just to add some pretty
sky_sphere {
 pigment {
  gradient y
  color_map {
   // http://povray.tashcorp.net/tutorials/qd_realskysphere/
   [  0/269 color rgb <120/255, 79/255, 51/255>]
   [  1/269 color rgb <141/255, 83/255, 46/255>]
   [  2/269 color rgb <177/255, 86/255, 41/255>]
   [  3/269 color rgb <235/255,128/255, 72/255>]
   [  5/269 color rgb <255/255,159/255, 72/255>]
   [  8/269 color rgb <255/255,203/255, 94/255>]
   [ 10/269 color rgb <255/255,218/255,112/255>]
   [ 13/269 color rgb <255/255,233/255,148/255>]
   [ 15/269 color rgb <251/255,241/255,172/255>]
   [ 20/269 color rgb <255/255,246/255,203/255>]
   [ 30/269 color rgb <255/255,240/255,219/255>]
   [ 40/269 color rgb <236/255,223/255,214/255>]
   [ 50/269 color rgb <205/255,204/255,212/255>]
   [ 55/269 color rgb <185/255,190/255,209/255>]
   [ 60/269 color rgb <166/255,176/255,201/255>]
   [ 65/269 color rgb <149/255,163/255,190/255>]
   [ 70/269 color rgb <129/255,149/255,182/255>]
   [ 80/269 color rgb <103/255,127/255,171/255>]
   [ 90/269 color rgb < 79/255,110/255,154/255>]
   [100/269 color rgb < 66/255, 97/255,143/255>]
   [110/269 color rgb < 52/255, 84/255,131/255>]
   [120/269 color rgb < 47/255, 75/255,122/255>]
   [140/269 color rgb < 37/255, 60/255,102/255>]
   [160/269 color rgb < 32/255, 51/255, 84/255>]
   [180/269 color rgb < 27/255, 42/255, 71/255>]
   [200/269 color rgb < 25/255, 36/255, 58/255>]
   [220/269 color rgb < 22/255, 31/255, 48/255>]
   [240/269 color rgb < 18/255, 27/255, 42/255>]
   [260/269 color rgb < 15/255, 21/255, 33/255>]
   [269/269 color rgb < 15/255, 21/255, 33/255>]
  }
 }
}


Cheers,
Edouard.

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Attachments:
Download 'aoi-micronormals.jpg' (35 KB)

Preview of image 'aoi-micronormals.jpg'

Christian Froeschlin <chr### [at] chrfrde> wrote:
> > Actually, that's good news (for me at least). For some reason I imagined the
> > slope pattern would rotate around together with the object
>
> yes, that's what I'd have still imagined yesterday, too ;)

.... so maybe strictly speaking it's bad because it is counter-intuitive?

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> I've used it to vary the blurriness of reflectivity based on the viewing angle

neat! I seem to get a reasonable result although maybe a bit
more grainy than yours. I used +a0.0 +r9, I don't know how to
get any higher ;) The jpg conversion may also be different.

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Attachments:
Download 'aoi-mn-3.7b31.jpg' (49 KB)

Preview of image 'aoi-mn-3.7b31.jpg'

Christian Froeschlin <chr### [at] chrfrde> wrote:
> more grainy than yours. I used +a0.0 +r9, I don't know how to
> get any higher ;)


Try.. +a0.0 +am2 +r3

Use higher +r values at your own risk ;)

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sooperFoX wrote:

> Try.. +a0.0 +am2 +r3
> 
> Use higher +r values at your own risk ;)

Happy with +a0.0 +am2 +r5

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Attachments:
Download 'aoi-mn-3.7b31-am2.png' (182 KB)

Preview of image 'aoi-mn-3.7b31-am2.png'

Christian Froeschlin <chr### [at] chrfrde> wrote:
> sooperFoX wrote:
>
> > Try.. +a0.0 +am2 +r3
> >
> > Use higher +r values at your own risk ;)
>
> Happy with +a0.0 +am2 +r5

I think my image was "+a0.0 +am2 +r4".

The result looks identical to the behavior I've been using in Megapov, so I'm
obviously very happy - thanks for your efforts!

Cheers,
Edouard.

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