Hi there, I've been a long-time Blender admirer and CG Cookie member, and with the release of 2.8, I'm making a serious commitment to learning it. However, I'm really struggling with managing RMB vs. LMB Select in 2.8, but probably not only for the reasons you're thinking.
For a long time, I've heard Blender experts insist that RMB select with a 3-button mouse is the way to go, so I moved away from my Apple Magic Mouse—which is very easy for me to use with my muscular dystrophy—and trained myself to use RMB as my primary mouse button on a three-button mouse (and it took a while to find a three-button mouse that my hand could tolerate). In other words, I use RMB Select outside of Blender:
Mac System Preferences showing that primary mouse button is set to Right
However, when I then choose the lauded RMB Select in Blender preferences, Blender flips my system-wide preference, so my physical RMB does not select objects; only my physical LMB does. This seems to be a result of Blender 2.8 assuming that everyone will have LMB as their system-wide primary mouse button preference, and simply reversing whatever the user's system-wide preference is.
That said, I'm wondering if this is a blessing in disguise, because I'm not sure if Blender's RMB Select would actually work for me until I understand the next question:
What are all the functional differences between LMB and RMB Select?
1. Gizmos?
LMB and RMB Select differences seem to go beyond merely whether the LMB or RMB selects an object:
LMB Select shows Gizmo options
RMB Select doesn't
What does "Activate Gizmo" and Press vs. Drag mean? If someone has RMB Select, where do the Activate Gizmo options go?
2. Dragging?
In addition, I notice that when I select an object while in RMB Select mode, my click goes straight to dragging the object. This feels risky to me, because I don't have the best fine motor control, so I don't want to drag objects accidentally (or have to perform another click to cancel the drag).
Why does RMB Select immediately drag an object, but LMB doesn't?
3. Menu vs. 3D cursor?
LMB Select results in the secondary mouse button showing a menu. RMB Select results in the secondary mouse button placing the 3D cursor. Why would someone prioritize one of these vs. the other? What's the reason for this asymmetry?
4. Other differences?
Are there other workflow implications of choosing LMB vs. RMB Select? For someone who wants to do modeling and animation, which functions will I be using most (i.e., which ones should I optimize for)?
5. How much can these be customized?
Could you, say, have LMB Select's secondary button do 3D cursor placement instead of opening menu?
I would greatly appreciate guidance, even an article on the above questions. Because of my disabilities, it's not easy for me to just switch buttons or switch mice. On top of that, I think if there were better explanations and solutions available, they could also help other unconventional users, such as left-handed users. Thank you!
What does "Activate Gizmo" and Press vs. Drag mean? If someone has RMB Select, where do the Activate Gizmo options go?
Here's a video on why Drag is a great option if you use left click select: https://cgcookie.com/lesson/selecting-through-widgets
If you're using right click select, however, it's unnecessary since there's no conflict between moving things and selecting.
Why does RMB Select immediately drag an object, but LMB doesn't?
Left click dragging always does whatever active tool you have selected (except when dragging on a gizmo as mentioned above), so you can actually get this behavior if you set the select tool to Tweak. I really don't like this behavior though, so I leave it on Box Select. I think the only reason that RMB Select dragging initiates a tweak is because that's what it did in 2.7 and is leftover for the folks that enjoyed that feature (it is fast to use).
LMB Select results in the secondary mouse button showing a menu. RMB Select results in the secondary mouse button placing the 3D cursor. Why would someone prioritize one of these vs. the other? What's the reason for this asymmetry?
To make it more standard with other apps. Right click is often used for context menus, but it doesn't make sense to swap it and make left click a context menu. For RMB Select, left click moves the 3D cursor just because that's what it did in 2.7.
Are there other workflow implications of choosing LMB vs. RMB Select?
Yeah, it's easier to select bones and stuff while weight painting with RMB Select, but beyond that not a whole lot that I can think of.
Could you, say, have LMB Select's secondary button do 3D cursor placement instead of opening menu?
Sure! Blender's hotkeys are all customizable via the Preferences.
For your situations, since your whole system is set to RMB select, I'd leave Blender as LMB select and have it be consistent with all of your other apps.
This is so wonderfully helpful! Thank you, Jonathan! Your responsiveness is just one more reason why I'm always impressed by the CG Cookie crew.