Hi Dan, could you please post a model file with the headlight and the surface you want to place it onto in the file?

That will make it easier for me to show you using your exact model. If I just create something from scratch it may have different proportions, or I may not understand what particular point you want to have as the point directly on the surface or things like that, it is just a lot easier if I can see your model rather than only having you describe it.

The Orient tool should be able to do what you want, possibly the part you may be having difficulty with is the picking of the source orientation frame. That will probably be something you want to have centered inside the headlight, it will be the "base point" that will then become the point that sits directly on the surface during the second phase of the orientation.


There are some other related tools that could possibly be easier for you to use, maybe try this - select your headlight and right-click the Copy button. The right-click there will run the "Copy with origin point" command instead of the regular copy. That lets you pick a point to define the base point of the copy, so pick a point centered inside the headlight which you would like to correspond with sitting directly on the surface.

Then Right-click on the Paste button, that will do a "PastePart" which will paste in the stuff from the clipboard but also let you set their orientation. Now pick a point on the surface and it will orient the headlight to be perpendicular to it. Oh also in this situation it will orient the original Z axis direction to be going along the surface normal, so for this case you want your headlight to be in a "rest" position pointing upwards.

That process with the source and the target done as 2 completely different steps may be easier for you to control. There are also keyboard shortcuts for those, you can use Ctrl+Shift+C for the copy with origin, and Ctrl+Shift+V for the paste with orientation.

The Orient command does the same kind of thing, but with all the steps combined into one command and also allows a full angular orientation of the base frame to be specified instead of only an origin point (with the z axis being implicit in the source direction in that case).

- Michael

Lots for me to consider there. In the meantime the exact model, complete with putative headlight, is attached!

Dan

Hi Dan, so to use Orient there are going to be a sequence of 4 clicks.

The clicks are in pairs - the first click will place the orientation widget, and then it waits for you to adjust the rotation so you'll then do a right-click to exit that stage.

So it's going to be like this: Left click, right click, left click, right click.

It's probably those right-clicks that are confusing you - each of those right clicks is actually the same as pushing the "Done" button, if you look in the upper-right area of the window you'll see a prompt that is telling you what MoI is expecting for you to do next, that can help a lot just in general operation to look at that area so that you can get an idea of what is going on right at that step.


So start by selecting your headlight object (you may want to delete or hide the original source curve used to build it to get it out of the way).

Now run Transform > Orient.


The first click will be on the headlight, on the point that you want to relocate to be on the curved surface. Since your headlight is the same on the top or the bottom it doesn't really matter if you pick the top face or the bottom face for this, here I've picked a point in the center of the top face which looks like this:



After you've clicked there you can now adjust the base rotation, but in this case the default rotation is fine so you just want to exit this stage by pushing Done or right-clicking. If you look at the prompt in the upper right area of the window, you'll see it says "Adjust base axis orientation".

So after right-clicking (or pushing Done) you have now defined the base frame for what piece of the object will be placed on to the surface and also what direction on the object will be associated with the perpendicular direction on the surface.


Now comes the part for placing the target location. The prompt will now say "Pick target origin", so now go and click a point on your curved surface like this:




Now you can adjust the rotation if you want but the default is probably fine for you so just right-click or push Done at this point and you will be finished, getting this result:




Here's what it looks like in action:



But again note that there are actually 4 clicks being done there - left click on the headlight, then right-click to accept the orientation, the left-click on the target surface, then right-click to accept the target orientation.


A couple of things to watch out for - you can get messed up by snapping on to wires from the back side of the surface so you may want to turn off the hidden line display which you can do under the View palette with the "Display hidden lines" checkbox. Also similarly watch out for snapping on to the world x or y world axis lines as well. You may want to zoom in a bit on your target area so that you don't have too much of the screen taken up overlapping those axis lines.

Another thing is that picking the points like this will place the object to be kind of skimming along the curved surface and only touching it at a single point. So if you want to boolean the object you may need to push it in a little bit afterwards so that it is submerged a bit instead of only grazing at a point, or you can try to pick one of the orientation points to be sunken down in the one of the objects so that sunken-in point is used as the target .


Hope this helps!


- Michael

Hi Dan, also maybe a little demo here of what those "adjust axis orientation" steps are actually used for would help a bit.

Because you have a circular shape, it doesn't really matter how it is rotated left or right around the perpendicular. But for other shapes there may be some particular feature of the shape that you want to position.

Like here I use the "adjust orientation" steps to control orienting the tip of this asymmetrical shape.

I position the orientation widget so the base frame is set up with the x axis pointing towards the tip (this is done by dragging on the axis line and releasing the mouse over the spot you want it to point at), and then when placing the target orientation, when manipulating the target x axis it is like manipulating where that tip is pointing towards:



So that's a kind of shape where you may want to have more control over the rotations, that's why there is that second adjustment step for both the base and the target.

If the automatically determined orientation is fine for your case then you just right-click (or push the Done button or push Enter) to accept it instead of tweaking it.

Does that help to make more sense of the whole orientation process?

Also one other note - the reason why you can adjust the "base orientation" is so that you don't necessarily have to rotate the object around to point towards the world x,y,z axis directions before you do the orient. If you use one of the other methods like the "Copy with origin" method I wrote previously, that does not incorporate an adjustable base orientation, that just takes the world (or actually current CPlane) axis directions as the base one.

- Michael