Figuring out speed

I have a more general question that I see happening quite often in larger more complex definitions and kept me thinking for quite some time now. In my mind grasshopper works in a downstream manner (except for plugins like hoopsnake or the Galapagos engine).

When we consider the following model:

Slider 1-> Component A -> Component B

Slider 2 connects to B ---------------^

Component A takes a long time to calculate, displays via preview.

Component B is faster, no waiting here. Also displays via preview.

When I change slider 1 I expect waiting for a while before everything is calculated since A changes. When I change slider 2 I also have to wait very long... This is not what I expected since it does not affect component A.

This is an extremely simplified version, the situation I run into are a lot more complex but basically deal with the same principle.

Anyone got an idea why this is happening.

Replies to This Discussion

Permalink Reply by David Rutten on July 20, 2011 at 2:45pm

Hi Sander,

your expectation is correct, when you change Slider 2 it should only affect Component B. Are you using the Profiler to test for time? Could it be that a lot of time is spend meshing preview geometry?

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Michael Pryor on July 20, 2011 at 3:11pm

could it be because even though slider 2 bypasses A and goes directly to B, The change in B still needs to "recalculate" with the data from component A?

Permalink Reply by David Rutten on July 21, 2011 at 3:14am

No. When you modify Slider 2, it will expire the input parameter of Component B where the slider connects, the component itself and all output parameters of the component. If anything is connected to those output parameter that will be expired too.

You can test this by disabling the solver (the padlock icon on the toolbar) and switching on Fancy Wires. If you drag the slider all the wires that connect expired elements will turn orange, the other will remain grey.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Sander Mulders on July 21, 2011 at 1:28am

Most of the time I'm previewing just points... I expected that to be the simplest type of "geometry" to display.

I usually have the profiler on but switching it off doesn't have that much effect on speed.

Permalink Reply by David Rutten on July 21, 2011 at 3:17am

"I usually have the profiler on but switching it off doesn't have that much effect on speed."

It wouldn't. In fact, the Profiler won't make any difference at all on the performance, it will only slow down the frames-per-second performance of the display. I was just interested to see how long the Profiler though each component ought to take and how long an actual solution took.

Points and curves (and boxes, breps, surfaces as well if Shading is switched off) will not delay a solution. They will only slow down the viewport display speed.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Michael Pryor on July 21, 2011 at 7:09am

You would know best

RSS