Rotating a line from a point

Hey all. Need a little help again. I am cutting a custom fireplace surround. I took a picture, and followed the lines with the canvas. I calibrated the top, so its the right size, but the bottom is out of square and too narrow. I did some construction lines that are the width at the bottom that I want. How can I rotate the bottom to line up with my construction lines without changing the location at the top? when I try to do move/copy and rotate, even though I pick the top as the axis to rotate, it takes like 100 degrees to get it to line up, and it makes my line look strange.

I’m just running out the door but you should be able to rotate the whole sketch as long as there isn’t any opposing constraints applied.

If you export it upload an f3d file it’s always very helpful for explaining Fusion scenarios.

If you search f3d export up above you’ll find plenty of information on how that’s done.

I guess I dont follow about rotating the whole sketch.
fire place surround.f3d (1.1 MB)

I don’t know if this helps but I worked on the right leg by first removing a few restraints. Click once on a restraint and then hit [Delete].
Then select as much of the line as you can with a right selection box:

This is likely to select your construction line as well or at the very least the lower point of the construction line. To remove the construction line from the selection (after the first selection is completed), hold down [Shift] and left click on the item you do not want included on the move. Now you have most of the line you want to move:

Right click and select Move/Copy. First I will rotate. Start the rotation with the rotation handle. It turns out that 1.8 degrees was about right.

Now select the right arrow in the move dialog directional controls. The movement that matched up pretty close was 0.8.

Now you have a little clean-up work at the top. Repeat the process on the left side.

What you are facing is paralax. Many phone editing apps for photos will help you correct for that. There is, no doubt, something in Fusion that would do that. I just don’t know. Tin will help when he is available.

Edit: I tried to see if I could just pivot the line but never could form the right “axis” of movement. I am pretty sure that is what you were hoping to do. Again, TW is the man…or the jack-o-lantern who can do it if anyone can.

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Oh. I see TW might be back. I just practiced fixing the other leg and no surprises. Then you just select the entire drawing with a selection box, right click for move/copy and use the rotation handle. It turns out it was only needing a 1 degree movement. Don’t remember if it was negative or positive.

Edit: I see what you mean with the top line/arc. Any time I was selecting the side, I tried to avoid triggering a selection of anything in the top arc. If you see anything highlighting in the arc, don’t click the left mouse button or it will grab something up there. I suppose if I were more adept at this I would allow it to select and then de-select the parts I didn’t want. Those points and spline lines mess with me so I try to avoid manipulating them too much.

so, that last part you talked about rotating the whole drawing. Is that after you straightened both legs to get the sketch squared up? or are you able to some how rotate the drawing to get the legs parallel?

That is right. You could rotate it at first if you wanted. But, since you had the canvas and knew the leg needed to be a certain length and you could see the top of the arc was lower on one side, similar to the side: it is 6 of one half a dozen of the other.

(All I intended to write in this reply was “Yes” but it won’t allow that few of characters. I guess I went overboard the other way.)

Here is a image before I rotated.

I guess you can see that my vertical sides are not exactly plumb in the image that was rotated. Probably better to rotate first, then put in your construction vertical lines and then it would have worked out. Don’t listen to me.

haha Ok. I’ll be honest. I’m a bit lost. My issue, is that nothing about this drawing is really “square”. I have a template here of an old frame someone hand built and ground to fit the rocks of the fire place. It was an actual fire place with screen doors. A local outfit is converting it to a slide in wood stove, and want this new cut out to fit their unit, and still fit the rocks nicely on the outside.

I think I would be more comfortable with scribing on a piece of cardboard or at least have a laser line set up in the photo so you can have definitive parallel or plumb lines that are dimensioned.

Sorry I mixed you up. But…I quickly started back at the beginning of your sketch and quickly turned it so the arch was level (so to speak). This then messed with your construction lines so I restrained with with vertical restraints. Then a selected, rotated and moved the right side. Selected and rotated the left side (no movement was needed).
And voila:

that makes sense. How do you know how much to rotate to get that arched part fairly level?

It is actually pretty easy. Just start the movement and then click in the degrees box to enter a number, if it is too big add a tenth or two or three. You don’t have to commit to the angle until you actually click in the menu box [Okay]. Once you click “okay”, it is a done deal. Until that point, you can move over here or there, rotated, move it again, etc.

Obviously, you are looking at the grid lines to get a good approximation of what is level or plumb.

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The main hurdle here is the difference between Orthographic view ( CAD ) and a Perspective ( Camera) view.

You have taken this picture a little higher then center ( this is why it is narrow at the bottom ) and from about 8’ back. While is picture from a camera is a good representation of 3D reality on a 2D image, it does a poor job of capturing 2D information in a 2D image. 2D information is distorted because of our(the cameras) point of perception of it through 3d space.

While there are methods to “straighten” the photos information using the relationship of the camera lens to the object and field of view. This is not an easy undertaking and will still only be a interpretation .

This problem is one of the reasons I bought a 3D scanner.


  • Orthographic views are flat, non-perspective representations of objects that preserve the angles between lines and keep parallel lines parallel.

  • Perspective views are three-dimensional representations of objects that give the illusion of depth and distance by making objects that are closer appear larger than those farther away, and by having parallel lines converge at a vanishing point on the horizon line.



So do I understand that you always want to take your picture 90 degrees in both directions to have the best representation of the part?
Hope the makes sense

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@Knick Yes, It’s ideal to take a picture straight on as possible in both axis. But nothing will fully eliminate prespective.

You could reduce field of view by using a zoom lens at a distance. This would help minimize distortion.

But ultimately you cannot take an orthographic picture of reality.

a 3D scanner has the ability to triangulate points in space that’s why ultimately it’s the best tool for this kind of work. I also might be a little biased because today is new 3d scanner day for me, pretty excited about that.

Carl Sagan has a really good video explaining the flatland but here’s the modern video of it


So, are you the happy little sphere in this story? Dragging us squares around to visualize the Fusion 360 world as it really is.

That would be something: change your avatar into a tesseract object!

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@ChelanJim Here’s a screenshot of a few pages from one of my favorite books.



HIRAM BARTON, a consulting engineer of Etchingham, Sussex, England, had the following grim comments to make about Hin- ton’s colored cubes:


A shudder ran down my spine when I read your reference to Hinton’s cubes. I nearly got hooked on them myself in the nine- teen-twenties. Please believe me when I say that they are com- pletely mind-destroying. The only person I ever met who had worked with them seriously was Francis Sedlak, a Czech neo- Hegelian philosopher (he wrote a book called The Creation of Heaven and Earth) who lived in an Oneida-like community near Stroud, in Gloucestershire.

As you must know, the technique consists essentially in the sequential visualizing of the adjoint internal faces of the poly- colored unit cubes making up the large cube. It is not difficult to acquire considerable facility in this, but the process is one of autohypnosis and, after a while, the sequences begin to parade themselves through one’s mind of their own accord. This is pleasurable, in a way, and it was not until I went to see Sedlak in 1929 that I realized the dangers of setting up an autonomous process in one’s own brain. For the record, the way out is to establish consciously a countersystem differing from the first in that the core cube shows different colored faces, but withdrawal

is slow and I wouldn’t recommend anyone to play around with the cubes at all."


A projection of the 4th dimension, a 3d shadow.

(8) 4th Dimenssion quickly explained :open_book: by Carl Sagan #shorts #science #physics #interestingfacts - YouTube

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