Thomas de Groot <tho### [at] degrootorg> wrote:
>
> To exclude the window areas you would need a (for instance) black/white
> image alongside each tile and use the eval_pigment() test to exclude the
> window areas.
>

That sounds intriguing. Although, I'm not quite sure how to go about it, in this
case. Each building's face is actually a single squashed-and-stretched 'boxed'
pattern (with the window image tiles 'inside the box', and repeated.) And the
windows' reflection 'hold-out matte(s)' are just black-and-white masks-- but the
same size as the small image tiles. Just thinking out loud: For the eval_pigment
trick to work as I imagine, the final FULL boxed pattern would need to be
evaluated pixel by pixel, then another (larger) black-and-white 'holdout matte'
generated from that, to be used as the hold-out for the additional overall
'dirt' texture on the entire building face.(?) But I'm not sure how to actually
*generate* such an image, pixel by pixel. The only time I've ever done something
like that was to assign a tiny flat box to each evaluated pixel! Thousands of
tiny boxes, in other words, in a grid. I've never created an actual *single*
IMAGE that way.

The bigger *main* problem I'm currently running into is that 'patterned
textures' cannot have additional overlayed textures applied to them. (I'm
currently using texture{boxed{texture_map{...}}  and  texture{image_pattern...}
to create the building faces-- both(?) of which are considered 'patterened'
textures.) I haven't yet found a way to work around this limitation... and have
had to write some rather inelegant code just to get the buildings into their
current state!

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On 23-7-2017 12:15, Kenneth wrote:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>>
>> To exclude the window areas you would need a (for instance) black/white
>> image alongside each tile and use the eval_pigment() test to exclude the
>> window areas.
>>
> 
> That sounds intriguing. Although, I'm not quite sure how to go about it, in this
> case. Each building's face is actually a single squashed-and-stretched 'boxed'
> pattern (with the window image tiles 'inside the box', and repeated.) And the
> windows' reflection 'hold-out matte(s)' are just black-and-white masks-- but the
> same size as the small image tiles. Just thinking out loud: For the eval_pigment
> trick to work as I imagine, the final FULL boxed pattern would need to be
> evaluated pixel by pixel, then another (larger) black-and-white 'holdout matte'
> generated from that, to be used as the hold-out for the additional overall
> 'dirt' texture on the entire building face.(?) But I'm not sure how to actually
> *generate* such an image, pixel by pixel. The only time I've ever done something
> like that was to assign a tiny flat box to each evaluated pixel! Thousands of
> tiny boxes, in other words, in a grid. I've never created an actual *single*
> IMAGE that way.

Hmmmm... I may have been a bit fast in my answering. I need to think a 
bit about this. I am sure it can be done somehow.

> 
> The bigger *main* problem I'm currently running into is that 'patterned
> textures' cannot have additional overlayed textures applied to them. (I'm
> currently using texture{boxed{texture_map{...}}  and  texture{image_pattern...}
> to create the building faces-- both(?) of which are considered 'patterened'
> textures.) I haven't yet found a way to work around this limitation... and have
> had to write some rather inelegant code just to get the buildings into their
> current state!
> 
> 

yes, that is a huge hurdle. I have to browse through my files to see if 
something I did in the past might be relevant. I have that nagging 
feeling...

-- 
Thomas

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On 7/22/2017 11:27 PM, Kenneth wrote:
> "omniverse" <omn### [at] charternet> wrote:
>>
>> Main thing I was seeing was the cleanliness of the outer tops, especially
>> compared to the interior of roofs.
>>
>
> Fixed!
>
> I also added some 'rain stains' under the windows, of the two most prominent
> buildings in the attached image.
>
> Currently, the buildings look too 'clean'. I'd *like* to add some overall subtle
> stains to the structural faces of the buildings-- but not to the glass windows.
> And that presents a practical problem, of how to go about it (due to the TILED
> nature of the window images.) Simply painting stains onto particular areas of
> the image tiles would end up looking too 'regular' and repetitive. The stains
> need to be larger and more random (like overlaying a subtle bump pigment onto
> the entire building face-- minus windows!)
>
> Hmm, I need to give this some thought...
>

Have you thought about using a proximity pattern? Norbert made one a few 
years ago. Thomas used another one to good effect on a domed building.

-- 

Regards
     Stephen

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On 2017-07-22 06:27 PM (-4), Kenneth wrote:
> Fixed!
>
> [Snip]

On the building just right of center, due to the 3-D nature of the 
architecture, it is obvious that you just used an image map.

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Cousin Ricky <ric### [at] yahoocom> wrote:

>
> On the building just right of center, due to the 3-D nature of the
> architecture, it is obvious that you just used an image map.

Yeah; the buildings definitely need some 'dimensionality.' (I actually hadn't
planned on the camera looking at them so closely-- but the more I work on the
scene, the more I want the camera 'in and among' the buildings!) I've done a
crude heightfield test for the faces of one of the buildings, and the results
look promising; but my current scene code isn't yet set up for that. I
essentially need to re-write it-- I think--if I go that route :-(

Also, some of the image map tiles are of WAY too low a resolution for
close-ups... which I didn't plan for originally :-/ I may have to search through
my OWN hi-rez photos of building facades (that I've taken over the years) to
pick some better ones. OR try and write a complex 'facade generator' in POV-ray,
and use all procedural textures instead. More work!!

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"Kenneth" <kdw### [at] gmailcom> wrote:

>
> The bigger *main* problem I'm currently running into is that 'patterned
> textures' cannot have additional overlayed textures applied to them...

By the way: Because of this limitation, each building is actually TWO boxes,
scaled differently (by .0001 in certain dimensions) and *very slightly*
overlapped-- one box to show the front-back faces, the other for the left-right
faces. In other words, I couldn't use just ONE box with multiple textures like
this...

object{building_box
       texture{..front-and-back..}
       texture{..left-and-right..)
       ...
      }

.... because those would be 'overlayed textures'-- and are not allowed.

But it wasn't a big deal to do-- and rather fun to code ;-) You can't see the
tiny overlaps unless you look REALLY closely at the buildings' edges (I hope!)

POV-ray can also apply uv-mapping to a box-- but I didn't consider doing that,
because of the crazy/complex nature of my tiled-image code, my 'boxed' pattern
and image_pattern use, etc. etc. Maybe when my brain power increases by at least
a factor of 2, I'll give that a try :-P

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> "Kenneth" <kdw### [at] gmailcom> wrote:
> 
>>
>> The bigger *main* problem I'm currently running into is that 'patterned
>> textures' cannot have additional overlayed textures applied to them...
> 
> By the way: Because of this limitation, each building is actually TWO boxes,
> scaled differently (by .0001 in certain dimensions) and *very slightly*
> overlapped-- one box to show the front-back faces, the other for the left-right
> faces. In other words, I couldn't use just ONE box with multiple textures like
> this...
> 
> object{building_box
>         texture{..front-and-back..}
>         texture{..left-and-right..)
>         ...
>        }
> 
> .... because those would be 'overlayed textures'-- and are not allowed.
> 
> But it wasn't a big deal to do-- and rather fun to code ;-) You can't see the
> tiny overlaps unless you look REALLY closely at the buildings' edges (I hope!)
> 
> POV-ray can also apply uv-mapping to a box-- but I didn't consider doing that,
> because of the crazy/complex nature of my tiled-image code, my 'boxed' pattern
> and image_pattern use, etc. etc. Maybe when my brain power increases by at least
> a factor of 2, I'll give that a try :-P
> 
> 
> 

Why don't you try the cubic pattern?
It allow you to give distinct textures to each faces of a cubic shaped 
object. As your buildings are not cubes, you'll need to scale that 
pattern to fit.

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Alain <kua### [at] videotronca> wrote:

>
> Why don't you try the cubic pattern?

!!!

That's something I never thought of-- and have never used! I will definitely
take a look at it. Thanks!

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Kenneth wrote on 21/07/2017 21:05:
> I've been working on a 'city building generator'-- part of my earlier post re:
> 'green gas cloud.' I put aside the media cloud for now...
>
> Currently, the buildings are just randomly placed. I've made no attempt to put
> them into a 'street grid' yet. (Perhaps real-world real-estate prices will be so
> high in the future that buildings will NEED to be overlapped by economic
> necessity, ha!)
[...]

I like them! I'm curious to see further evolutions of your generator.
Paolo

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> Alain <kua### [at] videotronca> wrote:
> 
>>
>> Why don't you try the cubic pattern?
> 
> !!!
> 
> That's something I never thought of-- and have never used! I will definitely
> take a look at it. Thanks!
> 
> 
Neither did I.
I think that it did'nt exist before version 3.7...

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