Another possibility: the COLLADA exporter expects the lights to
attenuate a certain way, but the OSG plugin isn't setting any
attenuation parameters.
--"J"
Tomlinson, Gordon wrote:
One possible caveat to add, Plugins such as the OpenFlight simply
discards light sources when they are read from a file, mainly due to
the limitation OpenGL gives us by default in OSG which is 8 Lights
so I'm assuming without looking at the OSG colada plug-in that is most
likely doing the same, conversely you might getting 8 lights applied
to your model and its simply washing it out
Best bet is to have root around the source of the OSG Collada plugin
and see what it doing with the lights if any thing
also NOTE this list is for submissions nad related posts only and not
these types of OSG questions
/Gordon/
__________________________________________________________
/Gordon Tomlinson/
/Product Manager 3D
//Email / : gtomlinson @ overwatch.textron.com
__________________________________________________________
//(C)//:/ (+1) 571-265-2612*
*(W)//:/ //(+1) 703-437-7651//
"Self defence is not a function of learning tricks
but is a function of how quickly and intensely one
can arouse one's instinct for survival"
- */Master Tambo Tetsura/*
------------------------------------------------------------------------
*From:* [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] *On Behalf
Of *David Spilling
*Sent:* Wednesday, November 12, 2008 3:58 PM
*To:* Steffen B.; OpenSceneGraph Submissions
*Subject:* Re: [osg-submissions] osg Collada Plugin
Steffen,
Can I suggest you try to reply to the mailing list, rather than just
to me? Others might have a better idea.
In general, the issue of appearance preservation - and your specific
issue of material/lighting - within an art path is a vexing one. The
lighting equations used by a modelling package (3DS in this case) are
not necessarily the same as OpenGL fixed function. Similarly, the
meaning of all the various material coefficients within the lighting
model - even if they have the same name - may not be the same.The way
these various coefficients map to each other across file format
conversions also matters. In your case, there are two possible sources
of error : firstly the Collada exporter in 3DS, and secondly the
collada importer in OSG, neither of which I know much about.
I would use osgconv to convert your DAE into a .osg model, and then
examine that in a text editor, looking for colours and materials (and
even the lights themselves, if .osg will write them out). You could
even post your .osg model - so long as it's small enough - to see if
any of the rest of the mailing list spot anything.
Alternatively you could load your model, and then (I guess, because
I've never done it) traverse your scene graph with a custom visitor
looking for statesets that have lights in. Once you find some, you
could scale back their intensity one by one.
What would be good in general would be to have a look at the OpenGL
red book (old versions are available on line), or even
http://www.falloutsoftware.com/tutorials/gl/gl8.htm, to see how
lighting is applied. You might want to look at the globalAmbient
settings, although I guess you could test to see whether this was the
case by setting all your models lights colours to 0 0 0.
Hope that helps.
David
2008/11/12 Steffen B. <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>>
With one light it isn't bright but still more bright as in 3ds
MAX. Apart from the fact that i still going via collada do you
know how can i regulate the intensity of the lights.
For example:
i create a simple red box in 3ds max and put 8 omni lights around.
the box is now white because of the lights.
if i decrease the intensity of the lights in 3ds max i can see a
beautiful illuminated red box. but when import the box
in my programm everything is still white.
now it would be interessting to know if there are some setting in
opengl to regulate the intensity of the lights.
i hope you understand me
thanks steffen
----- Original Message -----
*From:* David Spilling <mailto:[EMAIL PROTECTED]>
*To:* Steffen B. <mailto:[EMAIL PROTECTED]> ; OpenSceneGraph
Users <mailto:[EMAIL PROTECTED]>
*Sent:* Wednesday, November 12, 2008 4:22 PM
*Subject:* Re: osg Collada Plugin
Steffen,
Are you still going via collada? Unfortunately I know nothing
about the Collada import route and how it handles lights
defined in a model file.
Does the same thing happen with only one light? I suspect that
OpenGL is just (correctly) adding up all the contributions
from the various lights you have and consequently saturating
the output.
David
2008/11/12 Steffen B. <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>>
Hi,
i have turned the specular colour to 0 0 0 and it is a bit
better.
But i have another question. In 3ds max i can regulate the
ligth intensity
with the multiplier parameter. do you know how i can
regulate the intensity
with osg?
thank you for your efforts
_______________________________________________
osg-submissions mailing list
[email protected]
http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
