TurboCAD Forums

Turbo Talk => General Discussion => Topic started by: RCFlyingKnight on March 24, 2014, 07:20:50 PM

Title: Adding Knots or nodes?
Post by: RCFlyingKnight on March 24, 2014, 07:20:50 PM
Is it possible to add a knot or node to a spline without it being flat on the workplane? Vr. 18.2

I created a spline rotated  it 90deg, its on y,z instead of x,y and it won't allow me to add a knot or node.  I made a copy of the spline rotated it back to the x,y and "place on work plane" and it allows the addition of a knot or node (add knot in edit fit points, add node in edit control points).  So is it necessary for the spline to be flat on the current work plane or did I miss something?

Also, is it possible to mark where these Knot/nodes are for guide line placement or is it a guessing game?

I'm trying to do a loft, I have it to a basic shape now I want to fine tune it so to speak.

As it stands now I'm going to have to create a work plane at each profile and "place on work plane".  <---Is this the better way to do originally?
I could always rotate the profiles back to the x,y make some reference lines and intersect snap the nodes to the lines and the original profiles. (I took the profile with the most nodes and copy/matched it up to the other profiles for consistant node count).
Maybe I should have used a 3D spline instead.

Uh-oh I think I'm thinking to much again :(

Thank you,

Matthew
Title: Re: Adding Knots or nodes?
Post by: murray dickinson on March 24, 2014, 08:54:14 PM
You should be able to add a node, but not directly snapped to a feature.  If I'm understanding what's happening, in "edit  tool" mode, press the control key and trace the cursor over the curve, when it's in a suitable spot the little arrow towards the curve will appear and a click will insert the node.   Sometimes it seems to depend on the angle that you're looking at it, too, so swing your viewpoint around.  Maybe you're using the "fit edit point" mode, because although the little arrow towards the curve appears with ctrl, it doesn't insert the node when you click to do so, inserting them only works with "edit control point" mode, although you can then flip back into fit point.  IMO, 3D curves are more useful, and I don't find it necessary to format/place them on WP.
Title: Re: Adding Knots or nodes?
Post by: Henry Hubich on March 25, 2014, 09:31:01 AM
"Is it possible to add a knot or node to a spline without it being flat on the workplane? Vr. 18.2"

In Edit mode, with "Edit Control Points" enabled, hold the CTRL key and explore the curve with the cursor. When it looks like the attached screenshot, left-click and a new node will appear. As Murray sez, it only works when "Edit Control Points" is enabled in the Inspector Bar; won't work with "Edit Fit Points."

"Also, is it possible to mark where these Knot/nodes are for guide line placement or is it a guessing game?"

Double-click the curve to open its Properties dialog, click "Curve" in the left-hand panel, and enable "Show Frame." Control Points are the vertices of the "frame," and you can snap to them.

Henry H
Title: Re: Adding Knots or nodes?
Post by: RCFlyingKnight on March 25, 2014, 03:08:41 PM
Thank you gentlemen, pressing the Ctrl was what I was missing.  I had been placing cursor over the line, right-click and selecting add knot or node which ever was availible.

Interesting point to remember, the node will be added on the frame not on the spline.

Thank you,

Matthew