Recently I've been working on a project that has a lot of angled lines and then some times for selections or just for drawing i thought about using the cplane tool but using it in orthogonal views its kind of weird. All that times I just wanted to rotate the cplane in xy cause i was on the top view but if I clicked on a line, the tool aligned the new z axis with that line instead of aligning the x or y axis as I expected, i kind of understand why it happened but its just not what i think most people expect, cause the result is confusing (the top view now is the front one and the right is the top for example). I propose that in orthogonal views, for making the tool easier to use, the cplane tool work only in 2d.

Hi ed, I'm not really sure about having the cplane tool work totally differently depending on whether you're in a 2D view or a 3D view when you happen to place it...

Here's an example - say you want to place the cplane on to this curve at the point there to draw a cross-section curve perpendicular to that path curve at that station.



I'm not sure if I completely understand what you are asking for, but it sounds like you're asking for placing the cplane on to that curve to give a completely different result depending on whether it was placed in the Top view versus the 3D view?

That seems like it could easily lead to considerable confusion as well - particularly if you were in the top view to start with and you were planning on working in the localized top view of the cplane once you placed it...


If you just want to rotate the cplane from its current origin and not really place it anywhere else, the easiest way to do that currently is to just right-click or push "Done" at the prompt for placing the cplane origin - that will place the orientation picker right at the current cplane's origin and then you can grab the x or y axis and pivot it. And if you don't want the Top/Front/Right views to reorient into the new cplane's coordinate system you can turn that off by unchecking the "Orient ortho views" checkbox option inside the cplane tool.

Also you also may want to turn off the checkbox for "Align to objects" - that will prevent the z axis of the cplane from aligning to curve tangents or surface normals.


Basically with both "Align to objects" and "Orient ortho views" turned off it should give you the kind of 2d-only workflow that I think you're asking about...

Here's an example:




Note there that with "Orient ortho views" turned off, the 2D view that you're working in will not change to be relative to the cplane, the view stays the same and you will see the cplane angled instead.

If that doesn't do what you need, I'll probably need some examples to understand.

- Michael

well i did wanted the cplane to align with some curve drawn but just to rotate the actual plane like you said. A problem with placing the tool in the origin is that a lot of times you are far from it. Other problem i see is if you accidentally clic on some axis of the tool you change the rotation axis to something useless in the current view, you need to go to the 3d view and from there change the rotation axis to the original one. Whith this new "2D" mode i don't see any problem with the example you gave me of making a cross section.

Hi ed,

> well i did wanted the cplane to align with some curve drawn but
> just to rotate the actual plane like you said.

So to keep the views the same and only rotate the plane instead make sure to uncheck "Orient ortho views" and then it will make that happen - when "Orient ortho views" is unchecked the Top/Front/Right views will not have their point of view modified at all, they will remain looking at the exact same spot that they currently are, and so they will see an angled or moved plane inside of them.


> A problem with placing the tool in the origin is that a
> lot of times you are far from it.

In that case then don't do that right-click to make it placed at the cplane origin and instead uncheck the other "Align to objects" option before you pick the point to place the origin.

When "Align to objects" is off the origin point can be placed anywhere you want and the initial axis directions will be the same as the current cplane.

Having both "Orient ortho views" and "Align to objects" turned off should give you basic 2D behavior - you'll probably also want to have Object Snap and Straight Snap turned on in the bottom toolbar. With straight snap enabled you can drag an axis line and it will snap perpendicular or tangent from the origin point you picked like so:



That kind of snapping allows you to align to an object in a more 2D-manner as compared to the default method of aligning the CPlane's z axis to the curve tangent whch makes the entire plane perpendicular to the line (that behavior is enabled or disabled by "Align to objects")


So the key thing to get 2D behavior is to set:

Orient ortho views = Unchecked
Align to objects = Unchecked

By default both of those options are checked (and will be on the first use of every new modeling session), so you need to go uncheck them to get the behavior that I think you're asking about.



> Other problem i see is if you accidentally clic on some axis
> of the tool you change the rotation axis to something useless
> in the current view, you need to go to the 3d view and from
> there change the rotation axis to the original one.

I'm not really following this part - if you accidentally click on some axis you will set the "primary axis" to that one. Once the primary axis is set that means the other 2 axis lines will rotate around that one rather than orient to any free direction.

However, the primary axis is not restricted from being freely oriented, you can grab the primary axis (the one with the dot on it) and still just point it whichever direction you need.

Maybe I do not understand what you are referring to here, I may need to see a more step by step explanation.


> Whith this new "2D" mode i don't see any problem with the
> example you gave me of making a cross section.

If I understood you correctly the auto "2D" mode would not automatically align the z axis of the construction plane to the curve tangent setting it on a plane perpendicular to that curve, right?

In order to draw a cross section at a station along the curve, the cplane needs to be flipped up to be perpendicular to the curve which would not happen if it was only doing a 2D manipulation.

Right now the way it should work is that you can get the 2D type operation if you want by manipulating those 2 checkbox options.

- Michael

I see, that 2 boxes unchecked are the key! Thank you very much for your explanation!