Selectability in Solid Xray Mode #56915

New Issue

Julien Kaspar · 2018-09-25T12:18:16+02:00

Julien Kaspar commented

2018-09-25 12:18:16 +02:00

Blender Version
Broken: a933293f11

Short description of error
When enabling xray in solid mode, it is currently way harder or even impossible at times to select objects that are obscured. When in wireframe mode instead with xray enabled it's way easier and always works.

Stack a few different objects behind each other and try selecting them on different mouse positions.

**Blender Version** Broken: a933293f111 **Short description of error** When enabling xray in solid mode, it is currently way harder or even impossible at times to select objects that are obscured. When in wireframe mode instead with xray enabled it's way easier and always works. Stack a few different objects behind each other and try selecting them on different mouse positions.

Julien Kaspar commented

2018-09-25 12:18:16 +02:00

Added subscriber: @JulienKaspar

Brecht Van Lommel commented

2018-09-25 13:55:14 +02:00

Added subscriber: @brecht

Brecht Van Lommel commented

2018-09-25 13:55:14 +02:00

This is a bit vague, can you give a more specific example? I can't tell if you are referring to a bug, or a design issues in solid X-Ray mode.

With X-Ray in solid mode and for example a small cube in a bigger cube, then indeed you can't select the small cube directly. You have to click a second time to cycle to the next object. The problem is there are 4 faces overlapping the same pixel, and it's not obvious which is the one to prioritize. With wireframes you don't get this overlap.

Maybe we can find a better way to prioritize objects, though the general case seems difficult to do well.

This is a bit vague, can you give a more specific example? I can't tell if you are referring to a bug, or a design issues in solid X-Ray mode. With X-Ray in solid mode and for example a small cube in a bigger cube, then indeed you can't select the small cube directly. You have to click a second time to cycle to the next object. The problem is there are 4 faces overlapping the same pixel, and it's not obvious which is the one to prioritize. With wireframes you don't get this overlap. Maybe we can find a better way to prioritize objects, though the general case seems difficult to do well.

Jacques Lucke commented

2018-09-25 14:01:34 +02:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2018-09-25 14:01:34 +02:00

I can confirm that there is an issue.

It works at first but when I change the view slightly I can click as often as I want and the selection does not change.
selection.blend

[EDIT] I have not found a way to reproduce it 100% of the time yet unfortunately.. just click on the same pixel a couple of times, rotate the view, and click again multiple times. Repeat that until it does not work anymore. (it takes me at most 10 s)

I can confirm that there is an issue. ![selection.gif](https://archive.blender.org/developer/F4813734/selection.gif) It works at first but when I change the view slightly I can click as often as I want and the selection does not change. [selection.blend](https://archive.blender.org/developer/F4813751/selection.blend) [EDIT] I have not found a way to reproduce it 100% of the time yet unfortunately.. just click on the same pixel a couple of times, rotate the view, and click again multiple times. Repeat that until it does not work anymore. (it takes me at most 10 s)

Brecht Van Lommel commented

2018-09-25 18:05:40 +02:00

Ok, I can confirm that it sometimes stops working. Also the order of selection seems unreliable, depends if you look at it from the left or right. I would expect from near to far.

Clément Foucault was assigned by Brecht Van Lommel

2018-09-26 19:12:18 +02:00

Brecht Van Lommel commented

2018-09-26 19:12:18 +02:00

Added subscriber: @fclem

Brecht Van Lommel commented

2018-09-26 19:12:18 +02:00

@fclem, could you take a look at this?

Wireframe seems to have the same issues. I'm not sure if this is a recent regression or something that needs to be finished. But right now it's quite difficult for the animators to reliably select stuff.

@fclem, could you take a look at this? Wireframe seems to have the same issues. I'm not sure if this is a recent regression or something that needs to be finished. But right now it's quite difficult for the animators to reliably select stuff.

noki paike commented

2018-09-26 19:31:29 +02:00

Added subscriber: @nokipaike

noki paike commented

2018-09-26 19:31:29 +02:00

I just noticed this yesterday ... there is no wireframe mode no x-ray but the front selection is not highlighted (mostly), while the part hidden in the background yes

I just noticed this yesterday ... there is no wireframe mode no x-ray but the front selection is not highlighted (mostly), while the part hidden in the background yes ![Screenshot (25).png](https://archive.blender.org/developer/F4825522/Screenshot__25_.png)

Brecht Van Lommel commented

2018-09-26 20:18:42 +02:00

@nokipaike, that's unrelated to this task, let's stay on topic of the specific bug here.

noki paike commented

2018-09-26 20:28:27 +02:00

@brecht
sorry I thought it was relevant

@brecht sorry I thought it was relevant

Clément Foucault commented

2018-09-26 20:37:18 +02:00

Seems like clicking in some areas is not reliable but other is. Maybe it's the caching mechanism that is buggy. Will take a look at it.

Clément Foucault commented

2018-09-27 11:19:08 +02:00

Added subscriber: @ideasman42

Clément Foucault commented

2018-09-27 11:19:08 +02:00

After some searching it's caused by the "select wire first" that happens in xray. We do picking in 2 passes. One for wires and one for surfaces. If no hits in the first one we do the second.

It's because the non meshes are selectable in this pass too. This include the object center. So if you click near the object center it gets priority and we don't pick any surface.

My first thought was to just exclude the non meshes from the first pass. But that leads to all non meshes not being selectable if in front or behind a wireframe object in xray mode.

Second thought was to always do both pass (wires + surface and non meshes) and merge their hit masks but that means we loose the wire preemption.

I'll have to give it a bit more thinking but any help is welcome @brecht @ideasman42

After some searching it's caused by the "select wire first" that happens in xray. We do picking in 2 passes. One for wires and one for surfaces. If no hits in the first one we do the second. It's because the non meshes are selectable in this pass too. This include the object center. So if you click near the object center it gets priority and we don't pick any surface. My first thought was to just exclude the non meshes from the first pass. But that leads to all non meshes not being selectable if in front or behind a wireframe object in xray mode. Second thought was to always do both pass (wires + surface and non meshes) and merge their hit masks but that means we loose the wire preemption. I'll have to give it a bit more thinking but any help is welcome @brecht @ideasman42

Brecht Van Lommel commented

2018-09-27 12:06:30 +02:00

I think the object origin getting priority is not a problem in itself. That's potentially confusing but also helpful in other situations I think.

The problem I see is that it stops the selection selection cycling from working, where you click multiple times in the same spot and it selects the next one. I'm not sure how that is implemented currently, but it somehow should take into account both passes.

Besides that, selection order seems wrong regardless of the origins or X-Ray setting. It should at least be front to back within the wireframe and solid passes.

I think the object origin getting priority is not a problem in itself. That's potentially confusing but also helpful in other situations I think. The problem I see is that it stops the selection selection cycling from working, where you click multiple times in the same spot and it selects the next one. I'm not sure how that is implemented currently, but it somehow should take into account both passes. Besides that, selection order seems wrong regardless of the origins or X-Ray setting. It should at least be front to back within the wireframe and solid passes.

Clément Foucault commented

2018-09-27 13:09:34 +02:00

No the problem is that it stop cycling because the active object origin is getting selected in the 1st pass (the one that is supposed to select wires in priority) .

But since only wires (and non meshes) are rendered in this pass, it does not consider the surfaces and select the active object again because of the origin. If you click anywhere else where the object origins are not it will cycle through the objects correctly.

The problem is that non meshes will also trigger this bug. If you put a camera or empty in front of the objects in Xray it won't cycle through them.

Selection order seems fine here.

No the problem is that it stop cycling because the active object origin is getting selected in the 1st pass (the one that is supposed to select wires in priority) . But since only wires (and non meshes) are rendered in this pass, it does not consider the surfaces and select the active object again because of the origin. If you click anywhere else where the object origins are not it will cycle through the objects correctly. The problem is that non meshes will also trigger this bug. If you put a camera or empty in front of the objects in Xray it won't cycle through them. Selection order seems fine here.

Clément Foucault commented

2018-09-27 13:38:27 +02:00

I think I found a workaround. Will commit soon.

Brecht Van Lommel commented

2018-09-27 13:55:19 +02:00

To repro the selection order, what I do is:

Open selection.blend from above
Press numpad 3 (right ortho)
Selection order is Cube > Sphere > Suzanna > Cylinder (front to back)
Press numpad 9 (left ortho)
Selection order is still Cube > Sphere > Suzanna > Cylinder (back to front)

To repro the selection order, what I do is: * Open selection.blend from above * Press numpad 3 (right ortho) * Selection order is Cube > Sphere > Suzanna > Cylinder (front to back) * Press numpad 9 (left ortho) * Selection order is still Cube > Sphere > Suzanna > Cylinder (back to front)

blender-admin commented

2018-09-27 16:09:04 +02:00

This issue was referenced by a3fea39724

This issue was referenced by a3fea397244406e2f60c388ea651a200e5b3681c

Clément Foucault commented

2018-09-27 16:09:43 +02:00

Changed status from 'Open' to: 'Resolved'

Clément Foucault closed this issue

2018-09-27 16:09:43 +02:00

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Selectability in Solid Xray Mode #56915