Wrong snapping (active) in 2.71 (no active verts after extrusion, fallback snap median broken) #40993

New Issue

Maksym Tkachenko · 2014-07-08T17:05:11+02:00

Maksym Tkachenko commented

2014-07-08 17:05:11 +02:00

System Information
Linux Mint x64 (ubu 13.04), nvidia gtx560 (driver version 331.10)

Blender Version
Broken: 2.71

Short description of error
Wrong snapping. Just try next steps in 2.69 and then in 2.71

Exact steps for others to reproduce the error

open the attached file. two vertices are already selected
extrude them along the Y axis and snap to any vertex right to them in current viewport (E - Y - (hold Ctrl to snap) - (move mouse over the vertex))

In the 2.7 and older version selected vertexes will snap correctly and in the 2.71 they will fly away on the double distance.
around-3-bug.blend

**System Information** Linux Mint x64 (ubu 13.04), nvidia gtx560 (driver version 331.10) **Blender Version** Broken: 2.71 **Short description of error** Wrong snapping. Just try next steps in 2.69 and then in 2.71 **Exact steps for others to reproduce the error** 1) open the attached file. two vertices are already selected 2) extrude them along the Y axis and snap to any vertex right to them in current viewport (E - Y - (hold Ctrl to snap) - (move mouse over the vertex)) In the 2.7 and older version selected vertexes will snap correctly and in the 2.71 they will fly away on the double distance. [around-3-bug.blend](https://archive.blender.org/developer/F97088/around-3-bug.blend)

Maksym Tkachenko commented

2014-07-08 17:05:11 +02:00

Changed status to: 'Open'

Maksym Tkachenko commented

2014-07-08 17:05:11 +02:00

Added subscriber: @MaximTkachenko

NikoLeopold commented

2014-07-09 01:14:59 +02:00

Added subscriber: @NikoLeopold

NikoLeopold commented

2014-07-09 01:14:59 +02:00

confirmed on 2.71, Ubuntu 12.04 (elementary os).

seems to happen with 'snap active to target' only, and yeah, only when extruded.
as a workaround you may use the other options (median, center, closest).
also doesnt seem like double distance, but rather a constant offset (couldnt yet figure out what that offset depends on however).

will have a look at this.

confirmed on 2.71, Ubuntu 12.04 (elementary os). seems to happen with 'snap active to target' only, and yeah, only when extruded. as a workaround you may use the other options (median, center, closest). also doesnt seem like double distance, but rather a constant offset (couldnt yet figure out what that offset depends on however). will have a look at this.

NikoLeopold self-assigned this 2014-07-09 01:26:21 +02:00

NikoLeopold commented

2014-07-09 12:19:41 +02:00

This comment was removed by @NikoLeopold

*This comment was removed by @NikoLeopold*

NikoLeopold changed title from ~~Wrong snapping in 2.71~~ to Wrong snapping in 2.71 (no active verts/edges after extrusion)

2014-07-09 12:22:57 +02:00

NikoLeopold commented

2014-07-09 12:23:36 +02:00

Added subscriber: @LukasTonne

NikoLeopold commented

2014-07-09 12:23:36 +02:00

obviously the active vertex/edge simply is not set after extrusion, if you look for the white (active) dot/edge, it disappears after extrusion.

i wonder if this is intentional? when extruding faces a new active face is set, when extruding edges and vertices none is set active.
personally, i feel that to update the active element would be good, as many people might not be aware of the meaning of active and are confused by incoherent results.
another solution would be to snap to selected, when no elements are active.

or are there some cases when its necessary to have no active vertex/edge after extrusion? otherwise i would feel that it cant hurt..

obviously the active vertex/edge simply is not set after extrusion, if you look for the white (active) dot/edge, it disappears after extrusion. i wonder if this is intentional? when extruding faces a new active face is set, when extruding edges and vertices none is set active. personally, i feel that to update the active element would be good, as many people might not be aware of the meaning of active and are confused by incoherent results. another solution would be to snap to selected, when no elements are active. or are there some cases when its necessary to have no active vertex/edge after extrusion? otherwise i would feel that it cant hurt..

NikoLeopold commented

2014-07-09 12:27:58 +02:00

Added subscriber: @JonathanWilliamson

NikoLeopold commented

2014-07-09 12:28:42 +02:00

Added subscriber: @JosephEagar
Removed subscriber: @JonathanWilliamson

Added subscriber: @JosephEagar Removed subscriber: @JonathanWilliamson

Maksym Tkachenko commented

2014-07-09 12:31:38 +02:00

It has to be fixed, it is impossible to extrude in architecture now :(
And there were no active elements in the older versions. And everything worked great. Logically.
Please, fix it.

It has to be fixed, it is impossible to extrude in architecture now :( And there were no active elements in the older versions. And everything worked great. Logically. Please, fix it.

NikoLeopold commented

2014-07-09 18:15:08 +02:00

extruding works fine here, i assume you mean the snapping. did you try changing the snap target setting (right of the magnet symbol) from 'active' to something else? That should be a good workaround for most situations.

since the snapping in 2.69 seems to snap at 'median' when set to 'active' but none are active.
i think thats quite reasonable (and maybe better than assigning an active vertex). i hope that i can get some opinion of more experienced blender devs, i especially wonder whether the functionality was deliberately changed or by accident.
for now ill try to get to how it was in 2.69, i.e. snap median in 'active' mode when none are active.

extruding works fine here, i assume you mean the snapping. did you try changing the snap target setting (right of the magnet symbol) from 'active' to something else? That should be a good workaround for most situations. since the snapping in 2.69 seems to snap at 'median' when set to 'active' but none are active. i think thats quite reasonable (and maybe better than assigning an active vertex). i hope that i can get some opinion of more experienced blender devs, i especially wonder whether the functionality was deliberately changed or by accident. for now ill try to get to how it was in 2.69, i.e. snap median in 'active' mode when none are active.

ronan ducluzeau commented

2014-07-09 22:22:03 +02:00

Added subscriber: @zeauro

ronan ducluzeau commented

2014-07-09 22:22:03 +02:00

I agree with mangostaniko.
There is no bug. Just a bad use of snapping tool.
The interest of active element is restricted to object mode since a dev did a change that does not allow to have an unselected active face/edge or vert.
There is no chance to be able snap something on an element that is moving as a member of transformed selection.

@MaximTkachenko, change Active to Closest and it would work as you want. It was probably changed by a alt+wheel accident.

I agree with mangostaniko. There is no bug. Just a bad use of snapping tool. The interest of active element is restricted to object mode since a dev did a change that does not allow to have an unselected active face/edge or vert. There is no chance to be able snap something on an element that is moving as a member of transformed selection. @MaximTkachenko, change Active to Closest and it would work as you want. It was probably changed by a alt+wheel accident.

Maksym Tkachenko commented

2014-07-09 22:55:50 +02:00

No logic here :(
I use it so often (every day since I learned snapping one million years ago) and now you say, that it is not a bug, but a feature... Just today it threw me away from the work process nearly 10 times...
Some of the newly extruded vertices has to be active. What sense in keeping old vertices active in this situation?
But you are the bosses, of course :(

Sorry for my english)

No logic here :( I use it so often (every day since I learned snapping one million years ago) and now you say, that it is not a bug, but a feature... Just today it threw me away from the work process nearly 10 times... Some of the newly extruded vertices has to be active. What sense in keeping old vertices active in this situation? But you are the bosses, of course :( Sorry for my english)

NikoLeopold commented

2014-07-09 23:23:13 +02:00

no bosses, most of the guys here are volunteers who just want to help.
the question is whether we can help at all.
sorry to ask, is the difference between active and selected clear? as zeauro mentioned, using 'closest' you can get the functionality you want. otherwise you can just mark one of the selected vertices after extruding as active using ctrl-shift-click or similar.

as i said, ill look into getting back to 2.69 functionality where it falls back to median when you have no active vertex in the selection but im not sure if it would get accepted.

no bosses, most of the guys here are volunteers who just want to help. the question is whether we can help at all. sorry to ask, is the difference between active and selected clear? as zeauro mentioned, using 'closest' you can get the functionality you want. otherwise you can just mark one of the selected vertices after extruding as active using ctrl-shift-click or similar. as i said, ill look into getting back to 2.69 functionality where it falls back to median when you have no active vertex in the selection but im not sure if it would get accepted.

NikoLeopold changed title from ~~Wrong snapping in 2.71 (no active verts/edges after extrusion)~~ to Wrong snapping in 2.71 (no active verts after extrusion, snapping fallback to median broken)

2014-07-10 01:00:31 +02:00

NikoLeopold commented

2014-07-10 01:00:31 +02:00

Removed subscribers: @LukasTonne, @JosephEagar

NikoLeopold changed title from ~~Wrong snapping in 2.71 (no active verts after extrusion, snapping fallback to median broken)~~ to Wrong snapping (active) in 2.71 (no active verts after extrusion, fallback snap median broken)

2014-07-10 01:01:23 +02:00

NikoLeopold commented

2014-07-10 01:05:13 +02:00

ok i think i found what i would consider a bug. it seems like the fallback to snap median from snap active when none are active is actually intended and implemented, but its broken by a tiny piece of code.

since this is my first bug fix, ill find out how to post a diff and write all the details as soon as i have proper internet access (hopefully tomorrow).

ok i think i found what i would consider a bug. it seems like the fallback to snap median from snap active when none are active is actually intended and implemented, but its broken by a tiny piece of code. since this is my first bug fix, ill find out how to post a diff and write all the details as soon as i have proper internet access (hopefully tomorrow).

ronan ducluzeau commented

2014-07-10 10:58:14 +02:00

Sorry, I did a confusion not about the meaning of active but about the snapping target.

In fact, I am not used to use it.
I worked so many years only with shift s and active element as pivot point that even if it is broken, I would never say that it is impossible to work.
I made a rush at giving a workaround to maleficmax that reacted as he was playing his life.

There is only one active vertex, edge or face at a time and it dissappears after extrusion. So, no active target is available and then, snapping acts like median.
But snapping to active target is not broken when one element is active.

I don't see how and why it could be annoying to have an active element after extrusion.
Except if user have it as pivot point and do a scale or rotation. But user can choose an appropriate pivot point.

Sorry, I did a confusion not about the meaning of active but about the snapping target. In fact, I am not used to use it. I worked so many years only with shift s and active element as pivot point that even if it is broken, I would never say that it is impossible to work. I made a rush at giving a workaround to maleficmax that reacted as he was playing his life. There is only one active vertex, edge or face at a time and it dissappears after extrusion. So, no active target is available and then, snapping acts like median. But snapping to active target is not broken when one element is active. I don't see how and why it could be annoying to have an active element after extrusion. Except if user have it as pivot point and do a scale or rotation. But user can choose an appropriate pivot point.

Maksym Tkachenko commented

2014-07-10 11:08:26 +02:00

>>So, no active target is available and then, snapping acts like median.
Yes, it has to be.
Here are screenshots, this one shows what i am extruding
http://pix.academ.org/img/2014/07/10/279072db20c0a3fee04c958b4d2f82f7.png
and this one shows where everything flies away and the snapping point
http://pix.academ.org/img/2014/07/10/2ce96b65cc7846dda71d2c0de4331dfd.png
and this is how it used to be
http://pix.academ.org/img/2014/07/10/59db228d798f4f830ffb1ff10f598bde.png

*>>So, no active target is available and then, snapping acts like median.* Yes, it has to be. Here are screenshots, this one shows what i am extruding http://pix.academ.org/img/2014/07/10/279072db20c0a3fee04c958b4d2f82f7.png and this one shows where everything flies away and the snapping point http://pix.academ.org/img/2014/07/10/2ce96b65cc7846dda71d2c0de4331dfd.png and this is how it used to be http://pix.academ.org/img/2014/07/10/59db228d798f4f830ffb1ff10f598bde.png

ronan ducluzeau commented

2014-07-10 13:34:52 +02:00

It seems that problem is relative to default cube.
If you edit another primitive; snap active to target have no offset and is snapping to median after an extrusion.

Even in your .blend, if you delete part of mesh that represent a screw or a nut (I dont know); snap is working correctly.

It seems that problem is relative to default cube. If you edit another primitive; snap active to target have no offset and is snapping to median after an extrusion. Even in your .blend, if you delete part of mesh that represent a screw or a nut (I dont know); snap is working correctly.

Maksym Tkachenko commented

2014-07-10 13:49:32 +02:00

Yes, it happens not every time. In the default cube exuded vertices can even get only half way to the selected snap point) Not the double way, like my example does.

NikoLeopold commented

2014-07-10 23:38:20 +02:00

here it was broken for all meshes, the problem was that when none are active, it used the center of the active face (even if in vertex/edge selection!) as a replacement. just 4 lines of code caused this and they are commented with /* no */ so it seems a bit questionable. a fallback to snap median is actually implemented, but this 'replacement' bypassed it. after deleting those lines, it works very well here, falling back to snap median as intended by the original developer and obviously also many users.

the 'patch' (just 4 lines deleted ;) is awaiting review now (D640).

here it was broken for all meshes, the problem was that when none are active, it used the center of the active face (even if in vertex/edge selection!) as a replacement. just 4 lines of code caused this and they are commented with /* no */ so it seems a bit questionable. a fallback to snap median is actually implemented, but this 'replacement' bypassed it. after deleting those lines, it works very well here, falling back to snap median as intended by the original developer and obviously also many users. the 'patch' (just 4 lines deleted ;) is awaiting review now ([D640](https://archive.blender.org/developer/D640)).

Howard Trickey commented

2014-07-20 21:58:54 +02:00

Added subscriber: @howardt

Howard Trickey commented

2014-07-20 21:58:54 +02:00

The problem with D640 is telling when "none are active". There is an alternate method in the code for specifying "active face", and according to it, there is an active face here. It is not clear whether or not some other function depends on that.

I'm not sure we have a clearly stated definition of what "active" is. Is it the last element explicitly selected by the user? Or does it include the implicit selections that happen when you create new geometry and the code selects the new geometry (and if not, is the correct thing to do to clear the "active" state, including the bmesh->act_face one, after constructing new geometry?).

Assuming "Active" can be set by the implicit selection of newly constructed geometry, an alternate fix to this bug is in https://developer.blender.org/D664

I think perhaps Campbell needs to decide which of these, or maybe some other solution, is best here.

The problem with [D640](https://archive.blender.org/developer/D640) is telling when "none are active". There is an alternate method in the code for specifying "active face", and according to it, there is an active face here. It is not clear whether or not some other function depends on that. I'm not sure we have a clearly stated definition of what "active" is. Is it the last element explicitly selected by the user? Or does it include the implicit selections that happen when you create new geometry and the code selects the new geometry (and if not, is the correct thing to do to clear the "active" state, including the bmesh->act_face one, after constructing new geometry?). Assuming "Active" can be set by the implicit selection of newly constructed geometry, an alternate fix to this bug is in https://developer.blender.org/D664 I think perhaps Campbell needs to decide which of these, or maybe some other solution, is best here.

Howard Trickey commented

2014-07-20 21:59:22 +02:00

Added subscriber: @ideasman42

Campbell Barton commented

2014-08-25 07:16:55 +02:00

Added a different fix - D758, this works a bit differently to D640 in that it remaps selection history,

This has to be implemented for each tool, which is a bit of a drawback.

Added a different fix - [D758](https://archive.blender.org/developer/D758), this works a bit differently to [D640](https://archive.blender.org/developer/D640) in that it remaps selection history, This has to be implemented for each tool, which is a bit of a drawback.

blender-admin commented

2014-08-25 08:57:38 +02:00

This issue was referenced by ca1bca442a

This issue was referenced by ca1bca442ab3ae6ab4332a24a784a1c79bde4e27

Campbell Barton commented

2014-08-25 09:04:30 +02:00

Changed status from 'Open' to: 'Resolved'

Campbell Barton closed this issue

2014-08-25 09:04:30 +02:00

Campbell Barton commented

2014-08-25 09:04:30 +02:00

Closed by commit ca1bca442a.

Closed by commit ca1bca442a.

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Wrong snapping (active) in 2.71 (no active verts after extrusion, fallback snap median broken) #40993