Projection precision is zoom dependent #34706

New Issue

Georg K · 2013-03-20T00:19:14+01:00

Georg K commented

2013-03-20 00:19:14 +01:00

%%%--- Operating System, Graphics card ---
Ubuntu 12.04 x64, Radeon HD7770

- Blender version with error, and version that worked ---

Error in 2.66a and r55421

- Short description of error ---

When projecting vertices onto faces (probably with all other combinations as well), the precision of the projection is depending on how close you are zoomed in. It should always use maximum precision independently of the zoom factor.

- Steps for others to reproduce the error (preferably based on attached .blend file) ---

Hit G, Y , Ctrl - mouse move in the left viewport, leave Edit mode, select the object in the right viewport, enter Edit mode and repeat G, Y, Ctrl-mouse move, then compare results: At the beginning, the circle was perfectly aligned to the cylinder, so the middle vertices (X=0.00000) of the circle were at local coordinate X = 0.00000 and those of the cylinder were at X = -0.000001 (should be zero of course, but as close as I could do). After the projection, the middle vertices of the circle end up shifted to the left: if projected from a zoomed-out viewport (left), the offset is very much noticeable and the circle is no cirle any more. When zoomed-in as close as possible (right), the offset is non-existent, like it should be.

left : before: central circle vertices at X = -0.000001 after projection -0.04409 (and became jaggy, unusable result)
right: before: central circle vertices at X = -0.000001 after projection -0.00000 (like expected)
%%%

%%%--- Operating System, Graphics card --- Ubuntu 12.04 x64, Radeon HD7770 - Blender version with error, and version that worked --- Error in 2.66a and r55421 - Short description of error --- When projecting vertices onto faces (probably with all other combinations as well), the precision of the projection is depending on how close you are zoomed in. It should always use maximum precision independently of the zoom factor. - Steps for others to reproduce the error (preferably based on attached .blend file) --- Hit G, Y , Ctrl - mouse move in the left viewport, leave Edit mode, select the object in the right viewport, enter Edit mode and repeat G, Y, Ctrl-mouse move, then compare results: At the beginning, the circle was perfectly aligned to the cylinder, so the middle vertices (X=0.00000) of the circle were at local coordinate X = 0.00000 and those of the cylinder were at X = -0.000001 (should be zero of course, but as close as I could do). After the projection, the middle vertices of the circle end up shifted to the left: if projected from a zoomed-out viewport (left), the offset is very much noticeable and the circle is no cirle any more. When zoomed-in as close as possible (right), the offset is non-existent, like it should be. left : before: central circle vertices at X = -0.000001 after projection -0.04409 (and became jaggy, unusable result) right: before: central circle vertices at X = -0.000001 after projection -0.00000 (like expected) %%%

Georg K commented

2013-03-20 00:19:14 +01:00

Changed status to: 'Open'

Ton Roosendaal commented

2013-03-20 14:51:00 +01:00

%%%I never got the hang of it this snapping bizz in blender... nor do I see anything snapping here, or what's meant to snap even...
Unfortunately the person who added this in Blender is not active anymore, and no new maintainer has popped up.

I suggest to mark this as an orphaned code "todo" item in wiki.
Will leave it open a while for others to check who might be more successful understanding it. :)%%%

%%%I never got the hang of it this snapping bizz in blender... nor do I see anything snapping here, or what's meant to snap even... Unfortunately the person who added this in Blender is not active anymore, and no new maintainer has popped up. I suggest to mark this as an orphaned code "todo" item in wiki. Will leave it open a while for others to check who might be more successful understanding it. :)%%%

Georg K commented

2013-03-20 16:59:16 +01:00

%%%Sorry, I missed to add that you have to click on the mesh to confirm the snap, so the complete actions are G, Y, Ctrl - mouse move with the mouse cursor on the faces of the cylinder mesh and then click LMB to confirm.
To better explain what I want to accomplish, I attached another screenshot modeling something like a part of a modern kitchen faucet. In short, from a flat "2D" circle I am creating a curved, "3D" circle by projecting it onto the faces of the cylinder.%%%

%%%Sorry, I missed to add that you have to click on the mesh to confirm the snap, so the complete actions are G, Y, Ctrl - mouse move with the mouse cursor on the faces of the cylinder mesh and then click LMB to confirm. To better explain what I want to accomplish, I attached another screenshot modeling something like a part of a modern kitchen faucet. In short, from a flat "2D" circle I am creating a curved, "3D" circle by projecting it onto the faces of the cylinder.%%%

Campbell Barton commented

2013-04-22 23:14:21 +02:00

%%%fixed r56226.%%%

Campbell Barton commented

2013-04-22 23:14:21 +02:00

Changed status from 'Open' to: 'Resolved'

Campbell Barton closed this issue

2013-04-22 23:14:21 +02:00

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Projection precision is zoom dependent #34706