Need help !

Hi ,

I donot understand the t-output of the CLX(Curve&Line Intersection) component .I think it should stand for parameter(s) on the input curve(s), but it seems not...any tips？

Replies to This Discussion

Permalink Reply by David Rutten on April 26, 2010 at 10:02am

It does. Why do you think it doesn't?

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David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Danny Boyes on April 26, 2010 at 10:20am

I've found this to be not what I expected as well and had to use the CurveCP to get the correct value of t. But couldn't remember where I'd seen it to tell you.

Permalink Reply by David Rutten on April 26, 2010 at 10:27am

Weird, I just tested it (put the t output into the Evaluate Curve) and the result was correct. But I'm testing this in 0.7 which might behave differently...

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David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Vicente Soler on April 26, 2010 at 11:01am

The t parameter of the CLX component seems to be the parameter of the line, not of the curve.

For horizontal and vertical lines the start of the parameter matches the bounding box of the curve. I'm not sure about diagonal lines.

Permalink Reply by Alpha222 on April 26, 2010 at 12:12pm

Hi David,see the following picture :

It is strange that the t params is larger than 1 .And as Danny Boyes says, a CurveCP componnet has to be used to get correct ts.

Hi Vicente, the strange ts seems not the parameter of the line, for if the input line is changed ,these ts are the same.

Permalink Reply by David Rutten on April 26, 2010 at 12:25pm

I think Vicente is correct. Those two numbers (1.4 and 53.6) seem to correspond visually with the distance from the intersection line start to those points (left to right). Know that the intersection line is changed so that it only travels through the curve boundingbox, so the line you see on the screen is not the line that is used internally.

If I swapped the line and the curve in the intersection function, then the parameters would be reversed. If this is indeed the case, then it seems I have already fixed it for 0.7, because I can evaluate the curve at the [t] parameters and get my intersection points back.

--
David Rutten
david@mcneel.com
Poprad, Slovakia

Permalink Reply by Alpha222 on April 26, 2010 at 2:05pm

Thanks for this explanation.I know in gh some data types will auto translate from one type to another.And good to know we will get a more useful CLX component .Thanks.

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