EDIT:
Made general edits. I also realized I didnāt specify exactly how my proposed Orient to Surface option would work so Iāve added that now.
Okay, now I want to specifically bring up the stuff @DanielBystedt, @LudvikKoutny and @DanPool were talking about in the task comments: https://developer.blender.org/T57210
I really like most of Danielās proposed ideas. I love the idea for booleans and Draw on Selected, those things would really make this tool more than amazing.
However, I think that itās viable to eliminate the need for most of the current tool options, which would include letting the tool automatically decide the drawing plane.
Iāll show what I think the toolās options can be reduced to further down. I hope I can also demonstrate that automatic plane selection isnāt a magical feature that would somehow guess what the user wants to do, or a feature that limits the userās control, but that itās actually a fairly straightforward solution to several issues of the tool, and it wouldnāt make any common usage of the tool more difficult.
You could think of it as a solution to some problems which has the side effect of making the tool much simpler to use.
Iāll start with some problems of the tool.
For these first examples, Depth is set to 3D Cursor Plane, and Plane Axis is set to Z. Basically this means the drawing plane is set to be the grid floor.
Iāve also set the grid floor to be an opaque blue color so that itās more visible.
Problems:
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At low view angles to the drawing plane you canāt reasonably see the dimensions of the object youāre adding (except the height). It takes very little mouse movement to stretch the object several kilometers out. Controlling X and Y dimensions here requires an unreasonable amount of precision. Note the dimensions of the added object:
I think itās fair to say that the user will always orbit their view so they can better see and control the added objectās dimensions. This defines one situation where it would be reasonable to change drawing plane axis automatically.
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If the operation starts above the drawing planeās horizon, the result is very difficult to control. The tool has no way to ascertain depth in this situation and chooses an arbitrary depth as a fallback. Because the fallback depth most likely contradicts the userās selected Depth setting, the user canāt reasonably determine the dimensions and placement of the object. Remember my Depth is set to 3D Cursor Plane, but because Iām making objects above the horizon, the tool cannot respect that setting:
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If, during an operation, the cursor crosses over the horizon of the drawing plane, the operation will suddenly invert, no longer following where the cursor actually is.
In this video, I do two operations: one starting on the grid floor, and one starting up above it. Watch what happens in both cases when my cursor crosses over the horizon.
Because of these three issues, itās not useful to make objects at a low view angle to the drawing plane, or above it.
In these cases, it would make sense for the tool to choose a more suitable drawing axis automatically.
This would allow the tool to more often respect the userās selected Depth setting.
Automatic drawing plane selection would only affect these āproblem areasā which are too difficult to control, actually invert the userās control, or which otherwise disregard the tool settings.
Therefore automatic plane selection would not negatively impact the use cases that the tool can accomplish, it would just solve these problems and at the same time simplify the usage of the tool.
The next issue pertains more to the tool options:
- Itās difficult to control the result when Orientation is set to Surface but the Depth to something other than Surface.
You have to calculate in your head using the click location on the surface and the depth of the actual drawing plane in order to determine where the object will actually be made, which seems too difficult and imprecise to be useful.
Itās a bit easier to do if youāre facing directly at the surface that you click on. But when you do that, the height of the object is coming right at you or away from you, and then that becomes more difficult to control.
Depth is set to 3D Cursor Plane and Orientation set to Surface:
I donāt think this combination of settings is more useful than it is confusing. Especially in comparison to, say, a āsurface offsetā setting the user could change which would place the object an arbitrary distance above or below the drawing plane. Grease Pencil has that feature, in fact. But Iām not arguing for that feature hereā¦
Related to this point, I made a mistake in a suggestion from my previous post. I said:
I retract that, because Iāve realized there are common use cases in which a user might want to add an object at a surfaceās depth, but not oriented to the surface. For a small example, like this:
(I made some loop cuts on the original object for easy snapping points.)
This is also a factor in how Iām proposing to simplify the tool.
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Proposal / Solution:
I think that Add Objectās options can be reduced down to these (considering the toolās current functionality, so this isnāt including the features Daniel proposed):
Depth:
ā Place On Surface
ā Orient to Surface
(and the origin stuff too)
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I excluded Surface from the Depth settings and added a separate toggle called āPlace on Surfaceā.
If Place on Surface is turned on, then Depth can still specify what to do when the user adds an object in empty space. That way, the user could leave Place on Surface turned on while adding objects on and off of surfaces, without having to change settings and still being in control of Depth.
Like Daniel in his comment on the task, I excluded 3D Cursor View from Depth and added World Origin. Iām personally not against the inclusion of 3D Cursor View, I just donāt really understand how it could be used in practice. But I donāt think it causes any issues either.
Most importantly, Plane Axis and Orientation are gone and the only orientation option is the Orient to Surface toggle.
If Orient to Surface is enabled, it would basically be the same as setting Orientation to Surface and Plane Axis to Z in the tool now. I also think that Orient to Surface should be grayed-out and disabled if Place on Surface is turned off. As I said before, I believe the combo of surface orientation but non-surface depth is more confusing than it is useful. This would ensure the user doesnāt need to disable both toggles in order to avoid this confusing behavior.
Now, what could substitute the manual selection of a drawing plane axis?
I think the first three issues I listed in this post demonstrate that whenever the horizon of the selected drawing plane is on the screen, there is a potentially very large area in the viewport where the Add Object tool doesnāt work in a clear and useful way.
In these cases, itās not difficult to determine what plane axis would be preferable and give more useful results.
Using the userās view angle and cursor location, an ideal drawing plane can be found.
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Mockups:
- Hereās a mockup I made in Unity of the most simplistic approach, where the drawing plane is chosen based solely on how much it faces the view. In my mockups you can consider the white sphere to indicate the depth, pretend itās the 3D cursor:
Quite simply, it just āactivatesā the plane that is most perpendicular to the view.
However, this simple approach has a problem: if each plane axis has equal precedence in the toolās automatic selection, you have to look down much more than what feels natural in order to place objects on the Z axis, the ground plane. This wasnāt apparent to me until I started mocking-up how the automatic plane selection could work, comparing it with a couple 3D programs that have automatic plane selection with object-drawing tools. In trying to figure out why one of the programs felt much more natural and intuitive, I realized that it had a heavy bias to the Z plane.
This makes sense to me, considering gravity and all the implications that has. Itās probably why Blender has a grid floor and the view orbits around the Z axis.
- Hereās a refinement to the first mockup. It chooses the drawing plane by how much it faces the view, but itās biased toward the Z plane.
Iām just sorting the planes based on an absolute dot product of the view direction and the plane axis. I just multiplied this value for the Z plane by 3 before sorting.
Also, if the cursor goes above the horizon of the active plane, it falls back to the next best plane:
Hereās the same thing without the huge planes, just a floor and placement preview grid:
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This behavior is already quite good. In fact, I think itās already good enough to replace manual orientation, and itās simple too.
I think there are ways it can be improved, and Iāve come up with some theories on how to do so. But as it is, this would already solve the issues Iāve brought up here, and I think itās the simplest and best way to solve those issues.
One thing it would need is a simple indication (and it could be very simple) of the drawing plane: Some kind of shape drawn at the userās cursor (maybe a square, maybe a grid), with the plane axis color, and aligned with the plane. I think even just that would be clear enough to make automatic plane selection effortless for the user.
I think automatic plane selection like this is more than sufficient to replace manual orientation options, and would still leave the user capable of achieving all the same common use cases as with manual selection, but with greater ease and fluency.
But what does everyone else think? Did I miss some important factors?
thank you
