Access array attribute wrangle

[Cain&Able]

Hey, 

 

I have a bunch of points with 3 float attributes,  b[0] b[1], b[2]

 

If I want to access only the second attribute, specifically through a wrangle (for learning), how would I do this? 

 

I've tried

 

@foo = point(@p,"b",1) 

 

but that only returns the first attribute value. Presumably because I'm not asking for an array? 

 

Thanks! 

[mestela]

Could you post a hip of what you're trying to do? The question and your code could be interpreted in several ways, a .hip would make it clearer.

[Shinjipierre]

@atest = v@b[1];

[f1480187]

3-float is a tuple, not an array. Difference in attribute access:

foo = f[]@attr[1]

versus

foo = v@attr.y
foo = v@attr[1]

They also shows differently in Spreadsheet. Arrays displays as bulk of values inside brackets, tuples have a column per each component. 3-float is an attribute itself, not three attributes, so, if you want second component by retrieving an attribute from points, use constructs like this:

// For vectors, normals, colors, positions, 3-floats.
vector foo = point(0, "b", @ptnum);
float bar = foo.y;

// For float arrays.
float foo[] = point(0, "b", @ptnum);
float bar = foo[1];

But it is just a longer version of @-access syntax. Typically we use point() function when want to access an attribute of some specific point number, not from same point being processed.

[Cain&Able]

That's excellent! Thanks, perfectly explained and does what I need. 

 

Cheers