Is it possible to include the option to paste to the working plane? Normally the copy and paste options in MoI preserve the orientation of copied objects relative to the world plane. This is great and just as it should be. However, there are situations when I create a 2d object as a profile for a sweep or loft operation and would like to copy and paste that profile at several points along a curve in 3d space, oriented at each point in such a way that the plane on which the 2d profile object lies is perpendicular to the tangent of the curve at that particular point. I have been using the CPlane option to manually rotate each profile. It is great that the “pick CPlane origin” will by default orient the CPlane at each point along a 3d curve such that the Z axis is tangent to the curve at that point. After setting the CPlane the Top view shows the XY plane as the working plane, looking right down the Z axis at the origin. The 3d curve intersects the XY plane at the origin. I would like to be able to paste a 2d profile curve onto this XY plane. It is difficult and confusing to me to figure out each time how to rotate the profile shape in order to “flatten it out” onto the XY plane. Perhaps a Ctrl + click or an Alt + click or a checkbox when using the copy tool in the Transform Pallet. That way the location of the cursor in whatever particular view Top, Front, Right, 3d would indicate the working plane. Before you tell me to just sweep one profile along the curve to achieve the same thing, my purpose is to use the Scale, Rotate and Show pts tools in order to tweak the profiles before using the Sweep or Loft tools. Thanks.
-Dan

Hi Dan - in order to do a proper job of re-orienting any object in a controlled way, it is necessary to have a base reference plane, in addition to a target plane.

For a planar curve it could be possible to use the plane that the curve is in, but that will not work so easily for something like a solid that is made up of many planar pieces rather than just one.

So my general plan for that is that I want to add an "Orient" transform tool that will handle this kind of task, I don't think I can make copy/paste do it without forcing you to do extra steps to specify a source plane at the time that you did the copy, which would be weird for the cases where you did not intend to paste to a different orientation.

I'm not quite sure when I will be able to get to the orient command though.

In the meantime, from reading your description re: sweep - the first thing is if you want your shapes to be distributed uniformly through the sweep path, then you can use the "auto-place" mode of the sweep which handles that for you. To use auto-place mode, you put all the profiles flat on the construction plane a little distance away from the rail curve (outside of its bounding box). That will make MoI automatically distribute and rotate your curves to be perpendicular to the curve tangent, see here for some examples:
http://moi3d.com/1.0/docs/moi_command_reference7.htm#sweep


Otherwise, if you do need to paste copies of a curve oriented along a curve, try using Transform/Array/Curve for that. You can either make a large number of copies like say 200 of them and then select the ones you want to keep and do a Select/Invert and delete the other ones, or also with the v2 beta it is possible to drag a reference point on the curve for a distance of where to place a copy at a specific distance, like this:



That may be an easier way for you to get the job done currently.

- Michael

Thanks Michael. An Orient Transform tool sounds interesting. If such a tool would be much more versatile than my suggestion about a copy / paste option, then I hope you get a chance to work on that soon. It would be useful to me for the way I think and work with shapes in 3d.
Thanks for your suggestions on how to work in the meantime. In addition to those, I found another workaround which is a little complicated by has some distinct advantages over the others. It may be helpful to others. I wanted to place copies of a profile curve at specific points along a rail curve in 3d space. 1) Construct a curve in 3d space. 2) Use Pick Point on the Draw Curve pallet to place a point on the 3d rail curve. 3) Use Copy on the Transform pallet to place other points at specific locations along the rail curve. 4)Draw a profile curve comfortably outside of the bounding box of the rail curve so that you can later use the auto-place mode using the sweep command. Select it and note its dimensions in the upper right of the UI. 5) Use CPlane on the View pallet to set a plane origin at the first Pick Point. The default orientation of the X,Y and Z axes when placing a Pick CPlane origin on a curve is such that the Z axis is tangent to the curve at the origin. 6) Use the Plane tool on the Draw Solid pallet to center a plane on that pick point. The plane should be comfortably larger than the dimensions of the profile curve which you noted earlier. 7) Continue using the CPlane tool and the Plane tool alternately with each of the other Pick Points. These constructed planes should each be parallel to the tangent of the 3d curve at the point at which they intersect the curve. 8) Select the profile curve and Sweep it along the rail curve using the auto-place mode. While using the Sweep tool make sure that Cap Ends is not checked so that the sweep will create a surface rather than a solid, and I suggest setting the Twist to Freeform. 9) Select the newly constructed sweep object and using the Boolean Diff tool on the Construct pallet, select each of the constructed planes which intersect the rail curve and subtract them from the sweep object. (Some other Boolean operations may work as well.) 10) Without selecting the surfaces of the sweep object, select the edges that were formed by the Boolean operation. Use Copy tool and the Paste tool on the Edit pallet in order to create curves from these edges. 11) Select and Delete the segments of the sweep object surfaces. These curves are nearly identical to the original profile curve. They can be easily rotated and scaled before selecting them in sequence and sweeping them along the 3d rail curve to form some very interesting and beautiful shapes. The major advantage of this method is that MoI does most or all of the job of rotating if Twist is set to Freeform when doing the first sweep. The disadvantage of this method is that the created profile curves differ from the original in that they have hundreds more control points which makes tweaking the shapes using control points very difficult.
If you need to have identical profile curves, that is, having the same number of control points, The following method seems to work (I am not sure how or why): Create the original profile curve on the world XY plane, usually using Top View. Create Pick Points at any specific points along your 3d rail curve. Use the Copy tool on the Transform pallet to place copies of the profile curve at each pick point. Keep in mind as you select the base point that, when the profile curve is re-oriented, the rail curve will run through that point. Place the Pick CPlane origin on any specific point along the 3d rail curve. [It is critical that the default orientation of the Pick CPlane origin snaps to “point” If it snaps to Center or some other point on the profile curve, EVEN THOUGH IT OCCUPIES THE SAME POINT IN SPACE, it will affect the orientation of the CPlane axes. You may have to temporarily Hide the profile curve or disable some of the snap options. It does not work simply to orient the new CPlane Z axis to be tangent to the curve at that point.] At this point it requires only the one following rotation to orient the profile curve so that it lies on a plane perpendicular to the tangent of the curve at that point: After setting the CPlane Origin at each placed Pick Point, and switch to Right View, the profile curve will be viewed on edge and will appear as a line. Using the rotate tool pick the Origin as the center of rotation. Using the Right Viewport, Pick any point on the profile curve as the first reference point, remember that the profile curve will appear as a line. As the second reference point click any point on the 180 deg horizontal of the Right Viewpoint. The snap should read “180, Tan , Perp”. Again, I don’t know why this works, but it will work for every point and every change of CPlane orientation as long as MoI is free to choose the default orientation.
Thanks again, I appreciate all the hard work and genius (and wizardry) that goes into MoI.
Dan

Not little images? because it's some hard to follow the process :)

Sorry Dan, lost me also.

Brian

Wow! modeling with words.
Dan, can't you use the method Michael explains above using Transform/Array/Curve, and see the way he drags the first copy along the curve and automatically stays perpendicular to the curve, you could snap that to the first point on your curve and delete the others following, then repeat the process for the next point.
If you don't understand what I mean, I'll get a video going when I get home, or if anyone else has the time and understands this.

Cheers

Danny, I think you are right about using the method that Michael described above. I had not considered that you could use his method to locate at very specific points. That was the whole idea of what I was trying to do. Thanks! I will try that today.

To the others, Pilou and Brian: I have seen your awesome work in the forum and galleries. I am sure that even with little pictures there is not much that I could teach you about 3d modelling or MoI that you do not already know. But in the future, I will try to illustrate my descriptions with the use of screen capture images. I do not like to confuse people. Sorry

Dan

Dan

Feel sorry for us who don't have the language skills to explain our visualisations!

Brian