Challenge: Make the fastest island selection compound

iamVFX
Posts: 697
Joined: 24 Sep 2010, 18:28

Re: Challenge: Make the fastest island selection compound

Post by iamVFX » 18 Apr 2012, 16:16

I really like Oleg's compound. Result of it in a per point context and its fast

Image

Chris_TC
Posts: 411
Joined: 22 Mar 2010, 17:43

Re: Challenge: Make the fastest island selection compound

Post by Chris_TC » 18 Apr 2012, 18:42

iamVFX wrote:I really like Oleg's compound. Result of it in a per point context and its fast

Image
Where can this compound be found? The speed looks great, I'd love to try it out.

iamVFX
Posts: 697
Joined: 24 Sep 2010, 18:28

Re: Challenge: Make the fastest island selection compound

Post by iamVFX » 18 Apr 2012, 19:16

Chris_TC wrote:Where can this compound be found? The speed looks great, I'd love to try it out.
Here, the fifth post, but you have already tested it, didn't you?

Chris_TC
Posts: 411
Joined: 22 Mar 2010, 17:43

Re: Challenge: Make the fastest island selection compound

Post by Chris_TC » 19 Apr 2012, 17:00

Oh sorry, yes of course I have. I thought this was a different one.

User avatar
rray
Moderator
Posts: 1442
Joined: 26 Sep 2009, 15:51
Location: Bonn, Germany
Contact:

Re: Challenge: Make the fastest island selection compound

Post by rray » 10 Nov 2012, 01:52

some compounds here I made recently, work reasonably fast, based of Guillaume's method, but simplified
#1: "Initialize Island Lookups"
#2: "Get Island Locations": per point, fetches array of locations of all island points for subsequent attribute lookups, requires Compound 1 executed

Don't know how much this is already covered in this thread, just needed some quick search&paste place to post this in :)
Attachments
island.zip
(3.54 KiB) Downloaded 148 times
Softimage Resources section (formerly known as rray.de/xsi) updated Oct 01 2017

julian johnson
Posts: 9
Joined: 27 Apr 2010, 16:10

Re: Challenge: Make the fastest island selection compound

Post by julian johnson » 11 Nov 2012, 13:19

I never seemed to have any problems with Oleg's compound so I'm not sure this variant will work on other machines but in the attached scene I've used the same basic technique as Oleg (i.e. growing outwards from the initial vertices attached to the target poly) but tried to filter the search vertices so that you're not iterating over the same points. I set up a variant of the test scene with highly subdivided topology and my tree executes in about 1.75s and Oleg's in about 7.5s (on my machine).

http://www.exch.demon.co.uk/xsi/files/i ... nge_JJ.rar

Let me know if this a) works and b) if my timings are grossly wrong! On the surface it seems to do the job. The scene is 2013 SP1.

julian johnson
Posts: 9
Joined: 27 Apr 2010, 16:10

Re: Challenge: Make the fastest island selection compound

Post by julian johnson » 12 Nov 2012, 14:32

For completeness, just updated the scene to include a comparison of the two basic techniques a) iterating outwards as Oleg does and b) identifying all the polygon islands first and then deriving the island-to-be-actioned from the polygon index (similar to Reinhard's compounds above). The former is always about 30% quicker but the latter does give you the polygon island indices as a bonus.

http://www.exch.demon.co.uk/xsi/files/i ... island.rar

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest