Wire Capture is slow, recreating it in VEX?

[JonathanGranskg]

I'm using wires deform a ton of points and it is terribly slow and the capturing process is what's taking the longest by far. Preferably, I'd like to recreate it in VOPs or VEX. 

 

So does anyone know how the Wire Capture node works?

 

It sets four attributes, but I don't know what they mean. I guess the ones ending with w are some kind of weighting.

• wireCapture regn[0]
• wireCapture w[0,0]
• wireCapture w[0,1]
• wireCapture w[0,2]

In my case the regn and w[0,2] are both set to 0.0 and the w[0,0] is set to 1.0. The only one varying is w[0,1]. So what does the value mean? I think it's some kind of position along the length of the curve...

[pbarua]

Check these:

 

http://www.fourthwall.ndo.co.uk/HT_Otls.html

 

http://forums.odforce.net/topic/8877-gmvc-general-mean-value-coordinates/

[rafaelfs]

I'm using wires deform a ton of points and it is terribly slow and the capturing process is what's taking the longest by far. Preferably, I'd like to recreate it in VOPs or VEX. 

 

So does anyone know how the Wire Capture node works?

 

I thought I had issues with capturing in the past and it turns out that I was cooking my capture at every frame, which was an issue with how I wired my network. You might want to check tor that or if it still doesn't work, look at the pointdeform SOP: it's an asset built mostly with wrangle nodes and the code is all exposed for your learning pleasure!

 

Cheers

[JonathanGranskg]

I thought I had issues with capturing in the past and it turns out that I was cooking my capture at every frame, which was an issue with how I wired my network. You might want to check tor that or if it still doesn't work, look at the pointdeform SOP: it's an asset built mostly with wrangle nodes and the code is all exposed for your learning pleasure!

 

Cheers

 

 

I have to capture every frame because the input geo is changing every frame, but I'll take a look at the Point Deform SOP. Thanks for the replies.  

[michael]

I'd be interested in what kind of geometry you have that is changing every frame...

you might want to look into using attributeCopy - capture once and then copy the capture attribs for the next frames...

[edward]

In my case the regn and w[0,2] are both set to 0.0 and the w[0,0] is set to 1.0. The only one varying is w[0,1]. So what does the value mean? I think it's some kind of position along the length of the curve...

 

One value should be the actual "weight" captured by the region. The other two will be the closest uv coordinate on the wire to the captured point. For curves, only one of u or v will have meaning. The both of them only have meaning if you're feeding in NURBS surfaces instead of curves.

[JonathanGranskg]

One value should be the actual "weight" captured by the region. The other two will be the closest uv coordinate on the wire to the captured point. For curves, only one of u or v will have meaning. The both of them only have meaning if you're feeding in NURBS surfaces instead of curves.

 

Alright, thanks for the clarification.

 

Then w[0,0] has to be the weight because the weight range is set from 1 to 1.

Does anyone know how I can create this type of four floats attribute by myself (it seems to have some kind of custom name per component)? 

 

I think I have an idea of how I can solve this.

Edited March 11, 2015 by JonathanGranskg

[edward]

There're known as "index pair" attributes. Last I looked, I think they can only be created in the HDK, but can be queried from HOM.