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Re: Rendering transparent objects changed in M8

• To: mathgroup at smc.vnet.net
• Subject: [mg114232] Re: Rendering transparent objects changed in M8
• From: truxton spangler <truxtonspangler29 at gmail.com>
• Date: Sun, 28 Nov 2010 06:52:58 -0500 (EST)
• References: <iclfbi$l7r$1@smc.vnet.net> <ico23m$nh8$1@smc.vnet.net> <icqfvp$m40$1@smc.vnet.net>

On Nov 27, 7:37 pm, David Skulsky <edskul... at gmail.com> wrote:
> On Nov 26, 2:28 am, truxton spangler <truxtonspangle... at gmail.com>
> wrote:
>
>
>
> > On Nov 25, 9:55 pm, David Skulsky <edskul... at gmail.com> wrote:
>
> > > On my work machine (Mac Pro with an ATI HD 4870 graphics card) I foun=
d
> > > that transparent objects (i.e., objects with Opacity < 1) were not
> > > rendering properly under Mathematica 8; these same objects did render
> > > properly under Mathematica 7.
>
> > > I contacted Wolfram; they investigated the issue and promptly replied
> > > with an explanation and what I expect will solve the problem.
> > > Apparently the default method for rendering transparent objects was
> > > changed in M8 "from a BSP tree to a depth-peeling method," supposedly
> > > for speed purposes.  Evidently this change can cause problems on so=
me
> > > systems (mine!).
>
> > > Switching back to the BSP tree can be accomplished by adding a hidden
> > > option to Style:
>
> > > Style[Graphics3D[...], RenderingOptions->{"Graphics3DRenderingEngine"=
-
>
> > > >"BSPTree"}]
>
> > > I will not be able to test this on my system until next week, but
> > > Wolfram was able to test it on one of their machines and confirmed
> > > that it fixed the problem.  They also advise that this workaround h=
as
> > > not been tested on other ATI Radeon graphics cards.
>
> > > David Skulsky
>
> > Shame there isn't a web page on their site with bug fixes and work
> > arounds. Apart from being useful for users it would reduce the load on
> > their tech support people I would guess, because we could check out
> > the fixes and work arounds page before contacting them.
>
> > TS
>
> I like your idea and I hope you send it to Wolfram (and that they
> implement it).
>
> Meanwhile, I'll post any additional workarounds I learn about in this
> group (perhaps we should include "workaround" in the subject to make
> searching a bit easier).
>
> David

People have asked for a bugs list for ages and been ignored so I do
not see any point in contacting them. Likewise a resource for
undocumented or insufficiently documented functionality has been
called for before. Obviously the actual documentation is the place for
this but a about this -- I've never understood why all function
options are not documented with usage examples. Even though there is a
business case for it (reduce tech support time, get relevant user
required documentation to include in the next version) the company
prefers to keeps its cards close to its chest.