From: bam@rudedog.asd.sgi.com (Brian McClendon)
Newsgroups: comp.sys.sgi
Subject: Re: anti-aliasing, perfly, reality-engine: question
Date: 16 Oct 1992 00:35:51 GMT
Organization: Silicon Graphics, Inc., Mountain View, CA
NNTP-Posting-Host: rudedog.asd.sgi.com

Oh boy, RE questions!!

In article <33100@adm.brl.mil> C.G.C.vanDijk@io.tudelft.nl writes:
>A question concerning reality engine, perfly, and antialiasing:
>
>Two weeks ago, we got our Reality Engine update for out Crimson/VGX,
>one-span cheapest flavor ;-).  Some of the new demos are really
>amazing stuff: you could drop of your chair if you get too absorbed
>in the fly-thru-landscape demo's.  Great textures.  But..
>
>Anti-aliasing does not seem to work on this one-span Crimson/RE.
>
>Who knows what is going on?  Did I miss the fine print that says that
>a Reality Engine is a great machine for anti-aliased textures as long
>as you buy a 2 or 4 span version?  (Hey, we ordered this thing when it
>was still called Venice; we did not even have all the normal print.)
>
>I found out the following:
>
>- We did not get any hardcopy documentation with our Crimson/RE, and
>  the on-line documentation did not tell me enough.  Should I order
>  the m4-glgt-4.0.1-graphics manuals?

The manual was late and apparently went to the printers only last week.  I guess
that means you should see it in November/December (?).  If you have the
dev option installed, (I believe) you should get an update of the GLPG
because you ordered an RE, but check with your sales rep.

>- The perfly demo that I saw on another Crimson/RE had a button called
>  'anti-aliasing'.  When on, everything looks great.  When off, all the
>  lines go flickering, just as one would expect from aliasing.
>  Our demo does _not_ have this button (consequently the demo is aliased).
>  Can anyone tell me why not? Does this program do a getgdesc() call to
>  test if there is anti-aliasing available?  (I added my gdesc & hinv below).
If you have a 2 RM system, then the 1280x1024 display can have up to
8 multisamples to produce the AA you saw in the demo.

>- Our wireframe f-15 demo features line drawing anti-aliasing, seemingly
>  at normal speed (but a Crimson would do this at normal speed even in
>  software?!)
The wireframe F-15 demo looks nice, but really isn't graphics limited.

>- Our Inventor SceneViewer application features an anti-aliasing menu
>  option.  When chosen, redraw time goes to several seconds and the CPU
>  sighs heavily, suggestion software anti-aliasing.
As on the VGX, you need 2 RMs to get the hardware accumulation buffer
at 1280x1024.  The Inventor app is using accumbuf AA and falls back to
the software accumbuf if the hardware one is not present.

>- In the release notes it says that we can have multisample AA 'even
>  on the base configuration' RE if you setmon -x SmallWindow_60.  If your
>  monitor can handle it of course; mine goes beserk.  This small note
>  really scares me.  Does something like 'singlesample' AA exist?

1) polysmooth(PYSM_ON) works the same as the VGX and allows AA polys
   without multi-samples.  As always linesmooth(SML_*) works for AA lines.

2) The multi-sync monitor is included with an RE system, but not with
   the RE upgrade, so in your case the 960x680_60 option
   won't be viewable.  I highly recommend acquiring one as its cheaper
   than a 2nd RM and allows many different display options.
   A quicker solution would be to bring in a VGA monitor (with RGB in)
   and say: "setmon -x 640x480_60;killall Xsgi" and you'll get 
   16 multi-samples available for AA. perfly will then have an AA button
   selection.

3) The most confusing thing about RE is the flexibility of its framebuffer.
   As you change video output formats and number of RMs, the "pixel depth"
   available for GL frame buffers changes.  Reasonable tradeoffs can then
   be made between stereo, multi-sample AA, z-buffer size, RGB component
   size (8bits vs. 12 /component), and hardware accumulation buffer.


Until you get the new manuals, here's a list of new GL commands to
check the online man pages for:

texdef3d(n,nc,width,height,depth,image,np,param)
t3f(v)
t3d(v)
t3i(v)
t3s(v)
t4f(v)
t4d(v)
t4i(v)
t4s(v)
tlutdef(index, nc, len, table, np, props)
tlutbind(target,index)

mssize(samples,zsize,ssize)
mssample(mode)
msalpha(mode)
msmask(mask,flag)
mspattern(pattern)
multisample(enable)
getmultisample()

zbsize(planes)
RGBsize(mode)

getgconfig(buffer)

blendcolor(r,g,b,a)

monobuffer()
stereobuffer()
leftbuffer(enable)
rightbuffer(enable)


-- 
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 Brian McClendon                  bam@sgi.com                  415-390-1110
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Newsgroups: comp.sys.sgi