Re: [Flightgear-devel] Random Buildings

[Vivian M. <viv...@li...>]

Stuart

> -----Original Message-----
> From: Buchanan [mailto:stu...@gm...]
> Sent: 25 April 2012 10:20
> To: FlightGear developers discussions
> Subject: Re: [Flightgear-devel] Random Buildings
> 
> On Wed, Apr 25, 2012 at 10:06 AM, James Turner wrote:
> > For me, the builds are extremely expensive - no idea why. The actual
> density doesn't make a huge different (1.0 vs 2.0, I will experiment more
> later).
> >
> > Eg my draw + GPU times go from 15msec to 100msec when I enable
> random buildings. This seems suspicious, since this a single state,
texture and
> primitive set, right? I am testing over Berlin, so there's a lot of urban
tiles, but
> even so, it's a very drastic change.
> >
> 
> That's very suspicious.  There are a small number of states/primitive sets
> being used (for LoD purposes).
> 
> Even at density=1.0 in a large urban area there will be many thousands of
> additional vertices being drawn,  so it's possible that is saturating your
GPU.
> 
> One random thought - I think the texture (data/Textures/buildings.png) may
> still have an alpha channel.  It might be worth checking if that's the
case, and
> removing it.  (I'm not at my FG computer right now so can't check myself).
> 

Looks good here - minimal impact on frame rate.

Well done

Vivian