Re: change color optimization

• To: Doug Lindholm <lind@xxxxxxxx>
• Subject: Re: change color optimization
• From: "From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>" <billh@xxxxxxxxxxxxx>
• Date: Thu, 14 Feb 2002 17:34:19 -0600 (CST)

> The delay gets much worse when I have a set of satellite images in
> there. Maybe ImageRendererJ3D will help with that?

It might.

> > And every Data object will be transformed
> > that includes the affected Real (in your case, every Data
> > object that includes 'color').
> 
> The "color" type is unique for every Data object I have. So I am already
> doing as you suggest. Is there a problem with having too many ScalarMaps
> (e.g. on the order of 100)?

Not that I know of, but I don't have any experience with
more than about a dozen ScalarMaps.

> I don't see why changing the color table of one would affect the others.
> It takes as long (and sometimes longer!) to make a change as it does to
> initialize the whole display. It is as if everything is being
> recomputed. Is that the case? 

Like I said, a Control change should only retransform Data
that include the Control's ScalarMap's RealType. If something
else is happening, it would be useful to check whether you
are re-autoscaling every time (which will trigger retransform
of all Data in the Display).

> I'm thrilled with the animation performance I'm getting now using the
> AnimationControl approach. But the performance of changing properties
> (e.g. color) stinks. I guess that is the tradeoff we make in this game.
> However, it seems to me there is room for optimization. In addition to
> the point above (seemingly unneeded computations), what about rendering
> the visible time sample as soon as possible before cranking on
> everything else? I think it is about time I learn some Java3D. :-)

We do this in Vis5D, which is easier because Vis5D has
essentially a fixed MathType and fixed set of ScalarMaps.
It could be done for VisAD by writing custom DataRenderers.
There's a partially-done tutorial on this.

Good luck,
Bill

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  • Re: change color optimization
    • From: Doug Lindholm