Page MenuHome

Moving negative imperial units works incorrectly
Confirmed, NormalPublicBUG


System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: Quadro M5000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 388.16

Blender Version
Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-02-12 16:20, hash: rB77d23b0bd76f
Worked: None

Moving an object negative imperial units works incorrectly. Moving an object -X' Y" moves the object negative X feet but positive Y inches. It requires you to type -X' -Y" or -(X'Y") instead which is not how negative imperial units are written.

Exact steps for others to reproduce the error

  • Open blender
  • Click on the splash screen image to make it go away
  • In the scene properties, change the "Unit System" under "Units" to "Imperial"
  • Delete the default cube
  • Add a cube
  • Type "G" type "Z" type "-1" hit "Enter"
  • In the "Operator Panel" on the lower left hand side, type in -1'6"
  • Notice the cube move up 6" instead of down
  • The final position shows as -0.5 instead of -1.5

12 inches = 1 foot
3 feet = 1 yard
1,760 yards = 1 mile

Note: Everything including architectural plans/shop drawing in the US are in imperial units. We are so sorry world.

Event Timeline

I can confirm this behavior, but I don't understand much about imperial unity to understand how it should be.

Analyzing the user_string_to_number function, -1'6" is converted to (-1 * 1 + 6 * 0.0833333313) * 0.304800004
I suppose it should be converted to (-(1*1+6*0.0833333313 ))*0.304800004
But I need to do some research to confirm this.

I suppose it should be converted to (-(1*1+6*0.0833333313 ))*0.304800004
But I need to do some research to confirm this.

As an American, I can confirm that movement of -1.5ft is the expected result when entering -1'6".

Writing it out as -1'-6" (as seen below) makes no sense to me.

I am guessing that it is rare to write -1m50cm in metric, and that writing -1.5m would be more common.
So the fact that -1 m 50 cm and -1m50cm both result in -0.5m might be the expected norm in metric, but I suspect that this too is an odd "Blenderism."

Evan Wilson (EAW) renamed this task from Moving negative imperial units to Moving negative imperial units works incorrectly.Mon, Mar 9, 6:29 PM
Evan Wilson (EAW) changed the task status from Needs Triage to Confirmed.
Germano Cavalcante (mano-wii) changed the subtype of this task from "Report" to "Bug".Mon, Mar 9, 7:00 PM