[X3D-Public] X3D-Public Digest, Vol 60, Issue 8

Joe D Williams joedwil at earthlink.net
Thu Mar 13 12:04:02 PDT 2014

maybe try and track the Open GL and WebGL functionality being used to 
produce the effect. I have heard of a few ways to do what may be 
called an ambient illumination that is a product of total lifetime of 
each photon in the scene to simulate this global or background, 
scattered, shadows, indirect, or whatever it should be called, effect 
on a particular surface. Most of the limitations used to be computing 
power and most of all we need realtime, but still std X3D does not 
provide for this sort of effect.  However, I think we find that all 
necessary info is declared in the scene to allow more complex 
formulations to be built into a player. From your description, maybe 
the original author was working to achieve this effect of the 
cumulative ambient lighting environment.??

Also look at special features of a browser like BS Contact or other 
X3D tools. There may be extensions that can progress to std track.

Good Luck and Best Regards,

the best ref?

What is happening in X3D HAnim?

----- Original Message ----- 
From: "Luca Martini" <luca.g.martini at gmail.com>
To: <x3d-public at web3d.org>
Sent: Wednesday, March 12, 2014 1:37 PM
Subject: Re: [X3D-Public] X3D-Public Digest, Vol 60, Issue 8

>I already saw the lighting equations here
> http://www.web3d.org/files/specifications/19775-1/V3.3/Part01/components/lighting.html#Lightsourcesemantics
> I explained the problem very badly, sorry, it's my fault, I'll try 
> to be
> more specific.
> I'm doing my graduation stage in a company, and they have a 3D 
> environment
> which allows you to create your own virtual scenes. I've been asked 
> to
> implement a solution for an X3D exporter but unfortunately the main
> programmer of this environment doesn't work for them anymore and I 
> don't
> have all of his Virtual Reality skills, I'm just getting started. I 
> didn't
> have any problem in capturing diffuse, specular and emissive color 
> values
> of any material object from our environment and exporting them in 
> X3D, but
> I'm having some trouble in trying to understand how to do the same 
> with the
> material ambient color. Basically we have 3 values for the ambient 
> color
> (RGB chromatic space) that the user can set for a material object, 
> but in
> X3D the ambientColor attribute for the Material node is missing, 
> unlike of
> what happens for diffuseColor, specularColor and emissiveColor. 
> Having a
> look at the X3D lighting equations i found that it uses the
> ambientIntensity (scalar value) Material attribute to compute the
> "attributeColor" value, multiplying it for each component of the
> diffuseColor attribute, so if, for example, my ambientIntensity is 
> 0.2 and
> my diffuseColor is [1, 1, 0.5] my ambientColor will be [0.2, 0.2, 
> 0.1] *
> light[i].ambientIntensity.
> I think that our ambient color is instead a vector of 3 ambient 
> intensity,
> each corresponding to a color channel: in that case would it be 
> possible to
> implement a solution in X3D which allowed to have 3 
> ambientIntensity, one
> for R, another for G and so on, instead of a single ambientIntensity 
> scalar
> value? And most importantly could my inference about [our 
> environment's
> ambient color] = [ambientIntensityR, ambientIntensityG, 
> ambientIntensityB]
> have any sense for somebody who had good VR skills?
> Thank you for your patience and help.


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