POV-Ray : Newsgroups : povray.general : Use uniform texture : Re: Use uniform texture Server Time
20 Jun 2021 22:00:14 EDT (-0400)
  Re: Use uniform texture  
From: Alain
Date: 1 Jun 2012 20:58:15
Message: <4fc96527$1@news.povray.org>
> "sic2"<nomail@nomail>  wrote:
>> Alain<kua### [at] videotronca>  wrote:

>>>> Hi All,
>>>>
>>>> I have one question. Assume I have a union of several objects (each with its own
>>>> texture). Is it possible to disable these textures without using #if statements
>>>> and apply another texture X for the union (like pigment{Red}) ?
>>>>
>>>> Thank you very much!
>>>>
>>>>
>>>
>>> Any texture applied to a given object always override any texture
>>> applied to the union.
>>>
>>> You can comment out some textures.
>>> You can use some #if statement to conditionaly disable any texture.
>>> You can use the quick_color feature and use a lower quality setting.
>>> For that, you add quick_color Some_Pigment at the end of the texture
>>> block or after the pigment statement, and reduce the quality to a value
>>> of 5 or less.
>>> You can set the quality by using +qn on the command line like +q5.
>>>
>>>
>>>
>>> Alain
>>
>> I have tried disabling all the possible textures conditionally and then having a
>> object representing the union of all the other objects that make the scene.
>>
>> #declare allObjects = union {
>>
>> ....
>> }
>>
>>
>> object {
>>    allObjects
>>    pigment {Red}
>>    finish {ambient 1 diffuse 0}
>>   }
>>
>> However, this yields to such a picture:
>> http://s17.postimage.org/j30sg07a7/1st_pass.png
>>
>> As you can see some parts are black, while the white part is this way probably
>> because it's infinity. I really cannot understand what textures I have not
>> disabled that yield to such a picture. In fact, when I look at the those
>> specific objects there's nothing wrong to me.
>>
>> I am using MegaPov (I got used to it since I've a Mac) and I am afraid I cannot
>> set the quality parameter up.
>>
>> Also, I don't get why a pigment/texture applied to all the union does not
>> overwrite all the other pigments/textures.
>
> In addition to my previous message.
>
> Is it possible that some of the objects appear "black" because of their concave
> shape? (some of the objects, in fact, are bowls, vases, boxes, etc).
>
>
>

No, the shape should not bne an isue apart from some self shadowing. As 
you use ambient 1, this should not be an isue.

It looks like the "offending" objects are rather complexe compound 
objects themself? Possibly with several levels of CSG probably defined 
in several places, including some include files. And that, somewho, the 
have an explicite black pigment, or an ambient 0 in a lightless scene?

Any #include directive outside your union? Some bad includes contain 
undeclared objects that will apears by themself. Those are best used 
this way:
#declare Some_Object = #include "bad include.inc"


What do you get by removing that ambient 0, adding a reasonable diffuse 
value and using some light?
What about rendering using +q0? This will render as if EVERY single 
textures had ambient 1 and ignoring any light.




Alain


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