Several issues with Blender units and scale #61352

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Thomas Androxman · 2019-02-09T10:20:11+01:00

Thomas Androxman commented

2019-02-09 10:20:11 +01:00

Coming from a drafting background, Blender has me a bit confused in regards to grid, units, and scale such as:

a) In the attached file, adding an empty-Cube comes in as 2meters wide. Adding a mesh-Cube comes in (correctly I think) as 20cm
Empty.blend

b) Close Blender and reopen the above file:

Delete the mesh cube, change unit scale to 0.1 and add a new mesh cube.

    (Comes in as the same size as the empty wireframe cube. So far so good)

Change unit scale back to 1.0, delete the mesh cube and add a new one.

    This cube comes in as big as the one just deleted, but it should be the same size as in the original saved file. (seems as if Blender stops refreshing scale options unless the program is closed and reopened)

c) Add a bezier curve to the above file and go to edit mode. The fish-bones are too large.

d) Grid cannot be hidden in Ortho.

Press Num7 for front view. On the Overlays-> uncheck grid --> Nothing happens

e) In terms of UI design, the notion that we have a scale for the grid (overlays menu) that affects the size of new objects and also having a second unit-scale in scene properties is extremely confusing. I am not sure which of the two is intended as the master control for scale (is it the grid scale ?).

Coming from a drafting background scale is important both for export to 3d printers and manufacturing, but also helps the software avoid floating point errors when the models are in millimeters.

Coming from a drafting background, Blender has me a bit confused in regards to grid, units, and scale such as: a) In the attached file, adding an empty-Cube comes in as 2meters wide. Adding a mesh-Cube comes in (correctly I think) as 20cm [Empty.blend](https://archive.blender.org/developer/F6557512/Empty.blend) ![DifferentSizesFromTheSameScale.jpg](https://archive.blender.org/developer/F6557615/DifferentSizesFromTheSameScale.jpg) b) Close Blender and reopen the above file: - Delete the mesh cube, change unit scale to 0.1 and add a new mesh cube. ``` (Comes in as the same size as the empty wireframe cube. So far so good) ``` - Change unit scale back to 1.0, delete the mesh cube and add a new one. ``` This cube comes in as big as the one just deleted, but it should be the same size as in the original saved file. (seems as if Blender stops refreshing scale options unless the program is closed and reopened) ``` c) Add a bezier curve to the above file and go to edit mode. The fish-bones are too large. d) Grid cannot be hidden in Ortho. - Press Num7 for front view. On the Overlays-> uncheck grid --> Nothing happens e) In terms of UI design, the notion that we have a scale for the grid (overlays menu) that affects the size of new objects and also having a second unit-scale in scene properties is extremely confusing. I am not sure which of the two is intended as the master control for scale (is it the grid scale ?). Coming from a drafting background scale is important both for export to 3d printers and manufacturing, but also helps the software avoid floating point errors when the models are in millimeters.

Thomas Androxman commented

2019-02-09 10:20:11 +01:00

Added subscriber: @ThomasAn

Sebastian Parborg commented

2019-02-09 14:55:33 +01:00

Added subscriber: @ZedDB

Sebastian Parborg commented

2019-02-09 14:55:33 +01:00

Changed status from 'Open' to: 'Archived'

Sebastian Parborg closed this issue

2019-02-09 14:55:33 +01:00

Sebastian Parborg self-assigned this 2019-02-09 14:55:33 +01:00

Sebastian Parborg commented

2019-02-09 14:55:33 +01:00

b) is because the Add Cube operator saves the size of the added cube. So when you change the scale, it will still have the previous added cube size saved.

But yes, the unit scaling is a known problem and will be tackled later.

d) It was decided to only let the user toggle the grid on and off in perspective view (as the tool tip says):
https://developer.blender.org/D4116

e) the master control right now is the unit scale. The grid scale is only visual.

As you seems to know how you want this to work, and have experience in the area, could you draft up a proposal on how you want this to work over at:
https://blender.community/c/rightclickselect/

All of the things you listed are sadly not bugs but pitfalls that happens because of how all of this was implemented.
It would be awesome to have a nice proposal to go after when we have time to tackle this issue.

b) is because the `Add Cube` operator saves the size of the added cube. So when you change the scale, it will still have the previous added cube size saved. But yes, the unit scaling is a known problem and will be tackled later. d) It was decided to only let the user toggle the grid on and off in perspective view (as the tool tip says): https://developer.blender.org/D4116 e) the master control right now is the unit scale. The grid scale is only visual. As you seems to know how you want this to work, and have experience in the area, could you draft up a proposal on how you want this to work over at: https://blender.community/c/rightclickselect/ All of the things you listed are sadly not bugs but pitfalls that happens because of how all of this was implemented. It would be awesome to have a nice proposal to go after when we have time to tackle this issue.

Thomas Androxman commented

2019-02-09 20:21:57 +01:00

Fair enough. Being new to Blender and coming from the outside this is the golden time of opportunity to catch UI rough edges, before I get used to them and start ignoring stuff.

Thomas Androxman commented

2019-02-10 00:14:11 +01:00

Added the following UI recommendation

Added the following UI [recommendation ](https://blender.community/c/rightclickselect/bDcbbc/) ![UnitsUI-Suggestion.jpg](https://archive.blender.org/developer/F6563618/UnitsUI-Suggestion.jpg)

Sebastian Parborg commented

2019-02-10 00:30:27 +01:00

Looks good! Be sure to tell your friend and others so it can be up voted!

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Several issues with Blender units and scale #61352