Hi, I am a newbie to Houdini. I am making roof now but I got stuck.

I did copy to points but the direction is one sidede. I want to make it right direction like real roof not one side.

Please help. And if you guys can please explain the procedure step by step. Sorry I am real newbie to houdini.

before one makes a roof with copy to points ,one must know why the point exists and what are its orientations and how to control them
with great copying to points comes great "N" and great "up" and great "side" vectors and their information tab ,use this power wisely as it can copy millions and billions of primitives to millions and billions of points with supreme accuracy.

may the holy vectors assists you

Check this: https://www.sidefx.com/forum/topic/49665/ [www.sidefx.com]

"copy to points will rotate the copied geos based on certain attributes present in the template points such as N v and orient. I would suggest the best to use is orient, But N is simple it will align the z axis of your source geo to the normal of the template points"

In your example you could group the two sides separate, and have orient set for each accordingly.

Yes, the very basics of points attributes are essential to understand, so as to use any kind of copying or geometry creation from nodes such a Copy to Points or the powerful sweep node.

So, for what you're trying to achieve, I'd recommend to read this first:
https://www.sidefx.com/docs/houdini/copy/instanceattrs.html [www.sidefx.com]
At the very least the N and Up attributes, as a true beginner you don't have to worry just yet about orient and other 'delicate' attributes.


After that, these principles imply that you just have to ensure two steps:
- model/import and transform your individual base tile mesh with the proper orientation; here, I would just set its rounded/outer border toward the global Z positive axis; before plugin it in at the first input of your copy to points node.



- second input will receive the target geometry, for which you need to have set up, upstream of the copy2pts node, N and Up attributes at the very least. In this case I suggest tangent Normals, flowing along the slope of your roof. Obviously, as your initial pic show, you need to have diverging direction for each side of the rood. You can do that either by mirroring one side of the curve path (after they got their N attr.), cutting the paths, or inverting N attr for any X (let's say) positive points.



The kind of results to expect... using this expression in the 'target' group of the copytopoints node (granted, a quick and lazy way of doing it) to alternate tile position for each row. *:2 ^@P.x=0


Hopefully that will get you started.