[x3d-public] [x3d] Spec Comment by on 19775-1: Abstract X3D Definitions - V3.3: Material alpha modulation with Lighting on (Mantis 973)

[Don Brutzman]

Doug, again thanks for this response.

If you have some screenshots specifically illustrating the rendering differences that you are seeing between different browsers (i.e. for different lighting algorithms), that would be a helpful addition.


On 8/24/2016 9:35 AM, Don Brutzman wrote:
> Doug: thanks for this helpful specification comment.
>
> Roy has entered this topic as Mantis issue 973:
>
>     http://www.web3d.org/member-only/mantis/view.php?id=973
>
> Am moving this discussion to the x3d-public mailing list.  Additional insight is welcome.
>
>
> On 8/15/2016 9:56 AM, Spec Feedback wrote:
>> Comment on 19775-1: Abstract X3D Definitions - V3.3
>> 17.2.2.3
>> http://www.web3d.org/documents/specifications/19775-1/V3.3/Part01/components/lighting.html#Lightingon
>>
>> -----------------
>> "The Material's transparency field modulates the alpha in the texture. Hence,
>> a transparency of 0 will result in an alpha equal to that of the texture. A
>> transparency of 1 will result in an alpha of 0 regardless of the value in the
>> texture."
>> That doesn't seem to me to be what browsers Octaga, InstantReality, or
>> Cortona are doing, and its not what table 17-3 and the Lighting equation say
>> is happening. In the table, alpha is never 'modulated' ie there's never an
>> alpha= AT * (1-TM)
>> - freewrl version 3 and vivaty do modulate.
>> The following 29C, 29D .wrl have texture alpha and material transparency=1,
>> show differently as noted above.
>> http://dug9.users.sourceforge.net/web3d/tests/DebateModulateAlpha.zip
>> or directly:
>> http://dug9.users.sourceforge.net/web3d/tests/29C.wrl
>> http://dug9.users.sourceforge.net/web3d/tests/29D.wrl
>>
>> -----------------
>>
>> Submitted on Monday, 2016,  August 15 - 9:56am
>> by  (Doug Sanden )
>> IP: 75.159.141.42
>>
>> See: http://www.web3d.org/node/1694/submission/895
>
> all the best, Don


all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman