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"Przemek Loesch" <nomail@nomail> wrote in message
news:web.4207f0fd47077f18b0aac12c0@news.povray.org...
> I've noticed that making a spotlight shadowless causes it works like an
> ordinary point light. Is it intended? If so then how to make a shadowless
> spotlight?
> Also there is a difference between placeing the keyword before spotlight
> attributes and after them. The first situation creates a shadowless point
> light, and the second leads to the spotlight with shadows.
> I've read the documentation and it says only that "shadowless" should be
> placed before all spotlight and cyllindrical definitions or after them.
> Am I missing something or is this a bug?
This is an interesting issue. I tested the code that you posted in
povray.binaries.images and came across the same issue, with cylinder lights as
well (though in a different way).
I would have thought that the spotlight's cone of light would not be considered
the result of a shadow effect.
It seems however that adding shadowless to a spotlight removes the cone of light
completely and makes it identical to a point light with the shadowless keyword.
Oddly though, this behaviour isn't consistent with the cylinder light with the
shadowless keyword. While its cylinder of light is removed, it doesn't become
identical to a point light like the spotlight does (the light "faces" one
direction - in other words, it becomes identical to a parallel light with the
shadowless keyword).
That's a little strange...
In summary, it appears that:
spotlight + shadowless = point light + shadowless
cylinder light + shadowless = parallel light + shadowless
Perhaps this behaviour is by design, but it isn't intuitive in my opinion. I
would have expected that a spotlight with shadowless would still retain its cone
of light, but just wouldn't interact with other objects to cast shadows on other
objects (I just checked, and this is the way that 3D Studio MAX works - it still
retains its cone of light while not having other objects in its cone of light
cast shadows).
Lance.
thezone - thezone.firewave.com.au
thehandle - www.thehandle.com
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"Lance Birch" <-> wrote:
> spotlight + shadowless = point light + shadowless
> cylinder light + shadowless = parallel light + shadowless
It looks like this.
> Perhaps this behaviour is by design, but it isn't intuitive in my opinion. I
> would have expected that a spotlight with shadowless would still retain its cone
> of light, but just wouldn't interact with other objects to cast shadows on other
> objects (I just checked, and this is the way that 3D Studio MAX works - it still
> retains its cone of light while not having other objects in its cone of light
> cast shadows).
This is what I expected and was suprised not to get.
I can live without shadowless spotlight, but if existed it would be useful
in some cases. For example: now I have a scene with the building which is
illuminated inside. I want to use as few lights as possible (34 actually)
so "shadowless" allows me to reduce the number of them. But if they become
point lights I will lose control on what is illuminated.
Przemek
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