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<div class="moz-cite-prefix">On 10/18/2017 10:07 AM, John Carlson
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAGC3UEmas0rpT4=VaskHtpkGUynGesqgrZ39XXPek9LdKtU53w@mail.gmail.com">
<div dir="auto">I guess there's no way to get the graphics card
vendors into line, except to standardize the images output from
the graphics cards. Why don't we do that? Voltages anyone?</div>
</blockquote>
<br>
John,<br>
<br>
You appear to have forgotten about the primary input-to-user device
-- the display. Most displays are digital now, so checking voltages
is probably not enough, you would need to check the digital values
sent to the device. But devices aren't calibrated and degrade over
time.<br>
<br>
The X3D Conformance testing is carried out against a reference set
of images/movies by visual inspection. When it was created it was
determined that it could not be a pixel comparison for the following
reasons:<br>
<br>
<ul>
<li>Different OS may apply different color transfer functions when
displaying results</li>
<li>Different hardware (GPUs, displays, etc.) may use different
algorithms to render the output</li>
<li>Display and pixel sizes may vary independently from small
(think phone) to large (think room-size cave).<br>
</li>
<li>Human navigation is never exact or repeatable</li>
</ul>
<p>An application that produces widely different color results for
different runs is not very deterministic. <br>
</p>
<p>X3D is neither mathematical, nor engineering -- it is computer
"science" (in the abstract) and computer engineering (in the
implemented). It is intended as Greg Couch mentioned to "archiv[e]
the description of the scene". It is operating at the boundary of
what we can describe and what we can implement.</p>
<p>Leonard Daly</p>
<p><br>
</p>
<br>
<br>
<br>
<br>
<blockquote type="cite"
cite="mid:CAGC3UEmas0rpT4=VaskHtpkGUynGesqgrZ39XXPek9LdKtU53w@mail.gmail.com">
<div class="gmail_extra"><br>
<div class="gmail_quote">On Oct 18, 2017 1:00 PM, "John Carlson"
<<a href="mailto:yottzumm@gmail.com" moz-do-not-send="true">yottzumm@gmail.com</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="auto">I mean, are we mathematicians or engineers?
We appear to be engineers. I'm a mathematician looking
on in horror to what the engineers did to my wonderful
computing device.</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Oct 18, 2017 12:55 PM, "John
Carlson" <<a href="mailto:yottzumm@gmail.com"
target="_blank" moz-do-not-send="true">yottzumm@gmail.com</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="auto">Here's the possible scenario, I have a
vendor that says they meet the standard, but have
wildly different renderings between runs. Do they
get the X3D blessing because they implement the
format, or is there an image standard that they much
match, and who is doing the checking? Is it
automated? It would seem not. What use is a
standard which can't be verified?
<div dir="auto"><br>
</div>
<div dir="auto">Yes, I am aware of the X3D resources
thumbnails, I'm just wondering about any standard
certification of browser renderings.</div>
<div dir="auto"><br>
</div>
<div dir="auto">I'm laughing too. X3D appears to be
a joke.</div>
<div dir="auto"><br>
</div>
<div dir="auto">John</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Oct 18, 2017 12:45 PM,
"John Carlson" <<a
href="mailto:yottzumm@gmail.com" target="_blank"
moz-do-not-send="true">yottzumm@gmail.com</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0
0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div dir="auto">The question becomes, can I
expect a single browser to generate identical
pixels between runs, and if not, how is
testing done?
<div dir="auto"><br>
</div>
<div dir="auto">Thanks,</div>
<div dir="auto"><br>
</div>
<div dir="auto">John</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Oct 18, 2017 12:31
PM, "Greg Couch" <<a
href="mailto:gregc@cgl.ucsf.edu"
target="_blank" moz-do-not-send="true">gregc@cgl.ucsf.edu</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote"
style="margin:0 0 0 .8ex;border-left:1px
#ccc solid;padding-left:1ex">On 10/18/2017
08:53 AM, John Carlson wrote:<br>
<blockquote class="gmail_quote"
style="margin:0 0 0 .8ex;border-left:1px
#ccc solid;padding-left:1ex">
I am wondering if the X3D standard is
complete or extensive enough to provide
for pixel perfect equality between
browsers. This is important for
archiving. Has this been a goal?<br>
<br>
Thanks,<br>
<br>
Johb<br>
</blockquote>
<br>
Thanks for the laugh. The
OpenGL/Vulkan/Direct3D/etc. specifications
have never required pixel perfect equality
between graphics cards, so it has not ever
been a goal AFAIK. Are they close? Yes,
very close, but not pixel perfect. The
great thing about X3D is that you're
archiving the description of the scene not
the image of the scene.<br>
<br>
HTH,<br>
<br>
Greg<br>
</blockquote>
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</blockquote>
<p><br>
</p>
<div class="moz-signature">-- <br>
<font class="tahoma,arial,helvetica san serif" color="#333366">
<font size="+1"><b>Leonard Daly</b></font><br>
3D Systems & Cloud Consultant<br>
LA ACM SIGGRAPH Past Chair<br>
President, Daly Realism - <i>Creating the Future</i>
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