The need for 3d snapping has been discussed earlier. I'm interested to hear how the Fusion 360 Team is thinking of implementing it. Currently, I really like the 2D Sketch environment and I hope whatever the solution, it will build on the same user experience (instead of diverging the look and feel).
Here are some suggestions, based on building a component for a steel mesh.
The current state
For those new to the forum, Fusion 360 does not have 3d snap. It has snap (and plenty more) in the 2D Sketch mode - but not in the usual 3D space.
The way around (as suggested elsewhere in the forum) is to use Joint Origins and fix everything together with them. However, this is really strange for creating a component without internal moving parts. Joints are for movements, components (by their Fusion 360 definition) are parts that move, relative to other components. We shouldn't use (need) components for building something that doesn't have internal degrees of freedom. Ugh.
Ignore the Joint Origins in the screen shot, I'm not going to use them. Instead, I'll see how Fusion 360 could make this kind of construction clear, and intuitive to the user, as it already does in the Sketch side.
If I just start to move the blue (selected) bar, it's kind of difficult to even drag it near where it should be snapped. This is because I'm dragging in 3D and the "depth" of the drag dot seems not to be in my control. I end up with this:
The ends don't meet. The blue bar is behind the one I would like to snap it to.
How do other CAD programs solve this? Are there examples of 3D snapping UI's? (really - I don't know)
Suggestion #1 - a 'Projection' constraint
What I can see as a possible solution is reusing the fine features in the Sketch mode.
1. Let's create a work plane
Looking from above (right click on the sketch in Browser, 'Look at'), I place points on the sketch.
Now, if we can make the 3D elements be tied to these dots, that's (almost) it. We would in effect constrain the 3D model to always follow (changes in) the sketch.
In order to do that, we need a feature that pairs sketch elements to 3D model elements.
It could be called '3d constraints' and be yet another submode of the Sketch mode (like 'dimensions' and 'constraints' now are). It can also be just a new kind of 'projection' constraint.
Here the lowest entry is a new one - the icon is borrowed from that used for 3d models (just a place holder).
If I select the 'Projection' construct, I'd be able to select any 3d model location (while still in the Sketch mode) that would then constrain the 3D element so that it's projection matches the given sketch point. This should be somehow indicated visually to the user (as sketch does for its 2d constraints).
The feature could ask me whether I want to move the 3d element to the sketch plane, or just constrain the projection. If I choose to constrain only the projection, I can make another sketch and constrain the remaining degree of freedom through it (to the same 3d point).
This way, I could implement i.e. meshes easily, by constraining multiple bar end points to the particular sketch 2d points.
Suggestion #2 - snapping in 3d
Since simply moving a 3d element over another, and snap, turned out to be difficult, let's see another way that could do the snap without the need to resort to sketches.
Let's create construction points at the tips of the two bars.
If we now had a feature (like Assemble > Join) to join these two points (moving one of the elements) that would be it.
( Fusion 360 doesn't do this, since these bodies are within the same component, and only components can be joined to other components, as per their definition. )
The feature should probably be under 'Modify' (or simply come about if two or more elements have been selected and one does a right click). ( Let's leave 'Assemble' for the component stuff. )
( Hmm.. my use of construction points is not good here. They don't move with the bars. Bummer. )
The 'snap' feature would allow me to tie the two ends of the bars together (moving the first, like Join does for components). The connection should be like a ball joint (for points), allowing me to further manually move both the bars or add other snaps to fully constrain them.
#3 - use what is there now
I was able to get this, as a single component, done using Fusion 360 existing 'move' and 'split body' commands.
It looks right, but is not based on precise geometry. Especially getting the aligned section to be somewhat right was difficult since I can only control the rotation angle (in 'move'), not constrain it to go through the end points.
Maybe there is a workflow that can currently do this better (please suggest me one!). But it's telling that it's very hard to find one.
The lack of 3d 'snap' is my #1 grievance on Fusion 360, at this time. Whatever the solution, I hope it binds the amazingly nice Sketch mode feeling and usefulness of its constraints seemingly also to the 3d. Currently, it feels like the 2d CAD inside the 3d one is actually more powerful.
Can you reveal your plans on this? Thanks.