What is the benefit of "Lock Object Modes"

Question

I must admit that i disable the "Lock Object Modes" option whenever i start a new project. (Yes i know how to disable this permanently, but that is not what i am asking about). I probably am very ignorant about the true value and benefit of this option, but i honestly can not find anything about why to use this option, when to use it and how to use it for practical use.

All i find is when to disable it, why to disable it and how to disable it. So i am a bit lost, but apparently i am not at all alone with that :)

So the question i have is:

Is there any fundamental information on the benefit of "Lock Object Modes" ? (manual, tutorial, documentation, explanations, Youtube, whatever... )

Again: I am not asking for opinions but for reasons why this option is useful and how to make use of it. And i believe this is a question that fits well here (as it is also about sharing knowledge and not just about solving practical issues)

A Use case for demonstration

For more clearness let me add a use case that i try to handle with the default settings. This works smoothly in Blender 2.79 but i have not figured out the nice and correct way to get this done with the default Lock Object Modes enabled (available since Blender 2.80). Maybe it is important to mention that my workflow in Blender 2.79 does not involve the Outliner.

Lock Object Modes disabled

So... Say you have an armature and a rigged set of meshes (here 3 body parts):

Now lets say i want to weight paint the meshes and for ease of use i also want to select the weight groups by using CTRL-LMB on a bone. This is what we are using all the time with Blender 2.79 and the setup is done as follows:

• Select the armature and set it to Pose mode
• Select a mesh and set it to Weight Paint mode
• switch weight groups with CTRL-LMB in the viewport

You can do exactly the same workflow in Blender 2.80 and newer when you disable Lock Object Modes.

Lock Object Modes enabled

But we want to understand how to use Blender with its default settings. However, when the defaults are enabled, then in first place can not find a way how to use a similar workflow as mentioned above (and this is why i am asking for fundamental information about how when why use Lock Object Modes).

The problem is: When i set the Armature to pose mode, then i can no longer select the meshes. When i select the meshes and go to weight paint mode, then i can no longer set the armature to pose mode and i can no longer select the bones. However, there is one workflow that actually does something useful (as for my understanding):

• First disable Lock Object modes !
• select each mesh one by one and set it to weight paint mode
• select the armature and put it to pose mode
• select one of the meshes
• Finally enable Lock Object Modes !

Now i can select the bones with CTRL-LMB and the meshes with CTRL-LMB as usual. And because of the Lock Object Modes enabled, i now can only select the meshes in weight paint mode. I see how this has benefits.

But ... now i can rephrase my initial question into several smaller parts:

1.) Is there a better way to setup weight painting for multiple Objects while the default settings are not changed? (How?)

2.) Is it discouraged to use CTRL-LMB on the bones to switch weight maps? (Why?)

3.) What is the encouraged way to do weighting on rigged objects (When?)

Answer 1

Lock object mode is as the manual said "Restrict select to the current mode" The only benefit that i know is... If you turn it off, you will have the ability to switch between different objects that are in different modes.

Let me give you an example:

I have 3 spheres,i'm gonna keep the first one in object mode. then go to the ouliner, select the second one and switch to sculpt mode, and finally select the last one and switch to vertex mode.

If now you select the different spheres, you will notice that every sphere is using the mode that we previously selected, which could speed up your workflow if you are working with different object in different modes.

In previous version you could use Alt + LMB to select the objects, but that does not work with 3.1, also edit mode is not working (probably a bug)

Turn that ON and you will prevent that behavior

Answer 2

What it does? The Property limits the selection of objects to those having the same mode as the active Object.

When can this be helpful? when you want to avoid any mode switch during your current task.

An example where the property shows its benefits:

When you are animating a rigged object, then you have your Armature in Pose mode and you would want to only select bones. However, typically bones and meshes are placed close to each other, so it is very easy to accidentally select a Mesh instead of a bone during your work. This is a case where you would want to enable the Lock Object Modes property.

An example where the property is not useful:

When you are rigging and weighting Mesh objects, then you typically have your armature in Pose mode and your meshes in weight Paint mode. You would want to select bones and weight meshes in the same workflow. Here you must be able to select elements from Objects in different modes. This is a case where you want to disable the Lock Object Modes property.