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Timothy Normand Miller | 18 Jan 03:31
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[Kinda OT] Perhaps novice question about painting 3D scenes with alpha blending

I know graphics architecture, and I know how to do all the math.  But,
oddly, I've never actually used a 3D API like OpenGL, Direct3D or
Java3D.  Well, I'm trying to write a demo for a paper I'm presenting
at HPCA, and I've run into something odd.  I was hoping some with
actual front-end experience might be able to help me.  I figured since
this is a graphics mailing list, this wouldn't be horribly off topic.

I'm using Java3D to render a scene with lots of translucent planes.
If I make everything opaque, it's fine, because it's doing Z culling.
But I'm finding that the rendering order isn't near-to-far, as I
expected, but something perhaps related to the order in which I
created the scene elements.  As a result, when I turn on alpha
blending, it looks horrible.

I'm starting to worry that what I'm going to have to do is do all my
coordinate transforms up-front (rather than create a transform group
and transform the group), then sort by Z order, then add them to the
scene (and by trial and error determine whether it renders
first-to-last or last-to-first).

But I'm wondering if there isn't a better way.

Also, this makes me wonder... if you're a game designer, and you want
translucency, does the game engine have to order the scene from back
to front so that the alpha blending happens in the right order?  Or is
Java3D stupid and Direct3D and OpenGL handle this more intelligently?

Thanks!

--

--
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Timothy Normand Miller | 23 Nov 17:56
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To offer "@opengraphics.org" email address forwarding

Now that opengraphics.org has been transferred to Yann, we'd like to
offer "@opengraphics.org" email addresses.  For now, just forwarding.

Should we make this open to just anyone?

Or should we take nominations for people who have been long-time
contributors, so that there's some specialness or exclusivity to it?
:)

--

-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project
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Timothy Normand Miller | 17 Nov 02:09
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Re: Re: opengraphics.org domain going to expire

Thanks everyone.  I'm going to pay the bill first.  After I do that,
what do I need to do to transfer the domain?
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Timothy Normand Miller | 16 Nov 22:09
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Re: Re: opengraphics.org domain going to expire

If all we really owe is $35, then I'll just call and pay it now and
tell them that we want to transfer opengraphics.org to another owner.

Should we keep the traversaltech.com domain for any reason?  (I really
liked the name. :)  )

On Wed, Nov 16, 2011 at 4:06 PM, Matt <matt <at> mattkeenan.net> wrote:
> On 16/11/11 20:45, Timothy Normand Miller wrote:
>
> Several people have offered to take over opengraphics.org, which we
> appreciate very much.  We have a few things we have to resolve.
>
> So, here's our situation.  Since Traversal no longer exists (we moved
> the commercial rights over to Dapem, André's open source hardware
> venture), we miscommunicated with our ISP (Dreamhost), and ended up
> not canceling the account and also not paying the bill.  As a result,
> we owe them $35.  As well as traversaltech.com, we also registered the
> opengraphics.org domain through the same account.  In order to renew
> the domain, we'd have to pay the $35 for hosting Traversal, which we
> don't care about anymore.  It appears that if we just don't pay, the
> domain will expire on Dec 1.  However we don't know if Dreamhost will
> hold it hostage after that point or not.  $35 isn't much at all, so if
> that's necessary to get it released, I will pay it, but only if
> necessary.  Perhaps some people can shed some insight into this.
>
> As for who gets opengraphics.org, that's up to you guys... whoever
> finds it the most convenient.
>
> After expiry the domain should go into what is called a "Redemption Grace
> Period"; a zombie registration if you will. The time normally is a 30 day
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Timothy Normand Miller | 16 Nov 22:02
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What's going on with OGP? Here's something...

With my Ph.D. and family taking up most of my time right now, I
haven't gotten to work on OGP much.  But I haven't forgotten about it.

For my consulting work, I had to learn Java to write a cross-platform
app.  Separately, just as a way to further develop my skill, I wrote
this unrelated program:  https://sourceforge.net/projects/minuteman/

That's gotten me set up to work on what I REALLY wanted to do, which
is an IDE for chip design.  I mentioned this a long time ago.  One of
the problems with coding HDLs is the massive amount of error-prone
coding you have to do just to stitch modules together.  Get one wire
the wrong size, and you get misbehavior that causes to develop more
gray hairs.  If this could be done graphically, we could save a lot of
time and pain.  There are also lots of "standard" modules that can be
just pasted in and hooked up (fifes and various types of pipeline
stage templates come to mind).

I don't get much time to work on it, so I haven't gotten very far.
But here's a screenshot:
http://www.cse.ohio-state.edu/~millerti/HIDE-screenshot.png

When I have it to a point where it's really worth looking at, I'll
check the project into Sourceforge.

--

-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project
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Timothy Normand Miller | 16 Nov 06:51
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opengraphics.org domain going to expire

We're having some problem with our registrar, and the opengraphics.org
domain is going to expire.  Would anyone be willing to re-register the
domain with another registrar after that?

--

-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project
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Timothy Normand Miller | 3 Oct 18:36
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Need help maintaining wiki

We need a new wiki maintainer/editor.  Would someone be willing to do
some minor edits and spam removal while we're in a holding pattern?

I'll have my Ph.D. done early next year, and Andre should have his
project going sooner or later.  So it'll pick up again.  I've also
been doing some circuit design on the side here and there.  So OGP
isn't dead, but prominent members have been pulled in too many
directions for the time being.

Thanks.

--

-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project
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Timothy Normand Miller | 25 Aug 21:55
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Importance of denormalized floats?

How important are denormalized floats in GPUs?  For graphics, I would
expect very little.  For GPGPU, it might matter.

The reason I ask pertains to floating point multiplies.  If you want
to multiply by denormalized numbers, then the number of bits you have
to process may be more.

Let's think about what kinds of results you can get from a multiply
and how this applies to shifting.

  If you multiply any two denormalized numbers, you'll get an
underflow simply because of the exponent.
  If you multiply any two normalized numbers, then the smallest result
(ignoring the exponent) is 1.0, requiring no shift or adjustment to
the exponent.  The largest result you can get is 3.999..., which
requires the exponent (the sum of the operand exponents) to be
increased by 1 and the mantissa to be shifted right by 1.  (But to be
clear, since these are 24-bit numbers, their product is 47 bits, and
you have to discard the lower 23 bits (with rounding) to get back to
24.  Then you may shift some more.)
  If you multiply a normalized number by a denormalized number, then
things get complicated.  To get the most accurate possible result, you
have to look at all 47 bits of the raw product and attempt to shift
left to normalize.

For OGP, we care more about graphics, so we could just not bother.  If
we get a denormal, we special-case it or feed the pipeline so that it
naturally gives us a zero result.

Sugestions?  Thoughts?
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Luke Kenneth Casson Leighton | 22 Aug 11:43
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Fwd: [LLVMdev] Xilinx zynq-7000 (7030) as a Gallium3D LLVM FPGA target

this from nick on the llvm list

---------- Forwarded message ----------
From: Nick Lewycky <nicholas <at> mxc.ca>
Date: Mon, Aug 22, 2011 at 4:42 AM
Subject: Re: [LLVMdev] Xilinx zynq-7000 (7030) as a Gallium3D LLVM FPGA target
To: Luke Kenneth Casson Leighton <luke.leighton <at> gmail.com>

[-llvmdev]

I think this stuff is really cool personally, though I don't have time
to pursue it myself, and I don't think llvmdev is interested.

Luke Kenneth Casson Leighton wrote:
>
> On Sun, Aug 21, 2011 at 5:27 AM, Nick Lewycky<nicholas <at> mxc.ca>  wrote:
>
>>>> The way in which Gallium3D targets LLVM, is that it waits until it
>>>> receives
>>>> the shader program from the application, then compiles that down to LLVM
>>>> IR.
>
>>>  nick.... the Zynq-7000 series of Dual-Core Cortex A9 800mhz 28nm CPUs
>>> have an on-board Series 7 Artix-7 or Kinect-7 FPGA (depending on the
>
>>>  so - does that change things at all? :)
>>
>> No, because that doesn't have:
>>  - nearly enough gates. Recall that a modern GPU has more gates than a
>> modern CPU, so you're orders of magnitude away.
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Luke Kenneth Casson Leighton | 20 Aug 19:32
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xilinx zynq-7000 Dual-Core Cortex A9 with built-in 125k logic gates FPGA

it looks like xilinx may have laid the golden goose - can i ask people
here to help evaluate this:

http://www.xilinx.com/products/silicon-devices/epp/zynq-7000/index.htm

that's an incredible combination of a state-of-the-art FPGA, about the
same capabilities of a Spartan 3 4000, with an on-board 800mhz
Dual-Core Cortex A9.

the existing interfaces include some quite basic ones that should be
expected - USB2, I2C, CAN-bus, RS232 and so on, but then also include
2 Gigabit Ethernet and, in the case of the 7030 and 7040, multi-lanes
of PCI-e (between 4 for the smaller versions at 468 pins, and 12 for
the absolute largest 900-pin monster)

now, the possibilities for this kind of combination are very, very exciting.

1) as there are no proprietary hard macro cells such as 3D Graphics or
MPEG engines, the CPU will undoubtedly be FSF Hardware-Endorsement
Compliant.

2) (someone please check!) i believe that the capabilities of the 7030
version should be sufficient to take over from the Spartan 3 4000,
meaning that it could, in combination with the NEON instruction set,
actually be the next OGP hardware IC

3) with some care on the design, i believe it may be possible to
create a module which is, itself, a stand-alone computer yet that
exact same module could also plug into an OGP PCI-e card.
(Continue reading)

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Jack Carroll | 20 Aug 03:22
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Fwd: Economics of open hardware


Jack Carroll

----- Forwarded Message -----
From: "Timothy Normand Miller" <theosib <at> gmail.com>
To: "Jack Carroll" <mykrowatt <at> comcast.net>
Sent: Friday, August 19, 2011 7:04:57 PM
Subject: Re: [Open-graphics] Economics of open hardware

Did you mean to email me only?

On Fri, Aug 19, 2011 at 6:41 PM, Jack Carroll <mykrowatt <at> comcast.net> wrote:
> Hardware may appear to be zero-cost, when it's obsolete or otherwise no longer wanted, but still
functional.  But getting it from the person who has it to the person who wants it still has come cost, in
transportation and in making known the availability to the person who wants it.  There's no zero-cost
physical equivalent to an on-line server.  Services like Craigslist are about as close as we can come.
>
> Jack Carroll
>
> ----- Original Message -----
> From: "Timothy Normand Miller" <theosib <at> gmail.com>
> To: "Ilias K." <ilias.k.cs <at> gmail.com>
> Cc: open-graphics <at> duskglow.com
> Sent: Friday, August 19, 2011 11:44:47 AM
> Subject: Re: [Open-graphics] Economics of open hardware
>
> On Thu, Aug 18, 2011 at 10:20 PM, Ilias K. <ilias.k.cs <at> gmail.com> wrote:
>> P.S. I would gladly pay for OSH as well, as long as it's guaranteed to last
>> for a long time.Regardless of whether I am believed, I have to say I don't
>> care about getting something for nothing.
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Gmane