Texture Paint 'Bleed' is angled along UV edges #50831

New Issue

Ryan Pocock · 2017-03-02T01:38:49+01:00

Ryan Pocock commented

2017-03-02 01:38:49 +01:00

System Information
Windows 10
Nvidia GTX 970

Blender Version
Broken: 2.78a and 2.78c (tested on both of these)

Short description of error
When using the texture paint section of Blender, if the 'Bleed' setting is set to anything above 0, you will see that when painting along an edge of a UV in the 3D Texture Paint mode, the bleed works fine from the first vertex, but is angled towards the next vertex, meaning the bleed isn't consistent at all.

Exact steps for others to reproduce the error

Start with default cube
For quicker purposes, smart UV unwrap the cube with a margin (the error is with any unwrap)
Move into Texture Paint mode
Create a paint slot image texture of any size.
Change the options, bleed setting to anything above 0. To see the bug clearly, use a large number like 8px
Begin drawing along an edge of the cube.
View the UV and texture in the 'UV/image editor' and zoom in, you will see the painted bleed is angled, and fading back to 0px bleed towards the edges of the vertices.

**System Information** Windows 10 Nvidia GTX 970 **Blender Version** Broken: 2.78a and 2.78c (tested on both of these) **Short description of error** When using the texture paint section of Blender, if the 'Bleed' setting is set to anything above 0, you will see that when painting along an edge of a UV in the 3D Texture Paint mode, the bleed works fine from the first vertex, but is angled towards the next vertex, meaning the bleed isn't consistent at all. **Exact steps for others to reproduce the error** 1. Start with default cube 2. For quicker purposes, smart UV unwrap the cube with a margin (the error is with any unwrap) 3. Move into Texture Paint mode 4. Create a paint slot image texture of any size. 5. Change the options, bleed setting to anything above 0. To see the bug clearly, use a large number like 8px 6. Begin drawing along an edge of the cube. 7. View the UV and texture in the 'UV/image editor' and zoom in, you will see the painted bleed is angled, and fading back to 0px bleed towards the edges of the vertices.

Ryan Pocock commented

2017-03-02 01:38:49 +01:00

Changed status to: 'Open'

Ryan Pocock commented

2017-03-02 01:38:49 +01:00

Added subscriber: @autumnpioneer

blender-admin commented

2017-03-02 01:38:49 +01:00

#52453 was marked as duplicate of this issue

Andrey Penyaz commented

2017-05-04 22:06:02 +02:00

Added subscriber: @biliogadafr

Andrey Penyaz commented

2017-05-04 22:06:02 +02:00

I encountered the same problem, so I decided to add pictures

This is especially a problem when I need to paint around holes in UV.

I encountered the same problem, so I decided to add pictures ![2017-05-04 22.45.40.png](https://archive.blender.org/developer/F587919/2017-05-04_22.45.40.png) This is especially a problem when I need to paint around holes in UV. ![2017-05-04 22.42.20.png](https://archive.blender.org/developer/F587921/2017-05-04_22.42.20.png)

Dalai Felinto commented

2017-05-22 14:28:57 +02:00

Added subscriber: @dfelinto

Dalai Felinto commented

2017-05-22 14:28:57 +02:00

Please, as per the bug report guideline attach a file even if it's super simple.

Bastien Montagne commented

2017-05-29 09:55:58 +02:00

Added subscriber: @mont29

Bastien Montagne commented

2017-05-29 09:55:58 +02:00

Changed status from 'Open' to: 'Archived'

Bastien Montagne closed this issue

2017-05-29 09:55:58 +02:00

Bastien Montagne self-assigned this 2017-05-29 09:55:58 +02:00

Bastien Montagne commented

2017-05-29 09:55:58 +02:00

More than a week without reply. Due to the policy of the tracker archiving for until required info/data are provided.

Andrey Penyaz commented

2017-05-29 12:18:28 +02:00

I've prepared required scene:

BLEED_BUG.blend

Things to notice from this test scene:

I've prepared required scene: [BLEED_BUG.blend](https://archive.blender.org/developer/F611936/BLEED_BUG.blend) Things to notice from this test scene: ![Скриншот 2017-05-29 13.09.48.png](https://archive.blender.org/developer/F611940/Скриншот_2017-05-29_13.09.48.png)

Bastien Montagne commented

2017-05-29 12:31:30 +02:00

Changed status from 'Archived' to: 'Open'

Bastien Montagne reopened this issue

2017-05-29 12:31:30 +02:00

Bastien Montagne removed their assignment 2017-05-29 12:31:30 +02:00

Bastien Montagne commented

2017-05-29 12:31:30 +02:00

Thanks, reopening then.

Ryan Pocock commented

2017-08-08 22:38:44 +02:00

Any update? This is pretty detrimental to my workflow and a lot of artists i know, haven't seen any changes in 5 months

Stefan Werner commented

2017-08-08 23:23:00 +02:00

Added subscriber: @Stefan_Werner

ChameleonScales commented

2017-08-08 23:44:26 +02:00

Added subscriber: @ChameleonScales

ChameleonScales commented

2017-08-10 01:53:53 +02:00

It's not a bug but the behavior of the feature is a bit cheap.
The way it extends the pixels is as shown in this image (according to my experiments) :

Even with quads, it extends around the hidden triangles with the same method, which explains the non parallelism with the edges. Of course the edge inside the quad (the diagonal) doesn't get extended, as don't all the edges inside a UV island.
You can see it more clearly on these 2 examples (I added yellow lines to show the hidden triangles) :

The big question is : is this method the only possible one to allow fast enough responsiveness or can a better one be developed and work in real-time ?

Since this feature came out in 2.49 I'm guessing the modern computers can handle a better method.

What do you think b3d devs ?

It's not a bug but the behavior of the feature is a bit cheap. The way it extends the pixels is as shown in this image (according to my experiments) : ![Texture Brush bleeding method.png](https://archive.blender.org/developer/F702936/Texture_Brush_bleeding_method.png) Even with quads, it extends around the hidden triangles with the same method, which explains the non parallelism with the edges. Of course the edge inside the quad (the diagonal) doesn't get extended, as don't all the edges inside a UV island. You can see it more clearly on these 2 examples (I added yellow lines to show the hidden triangles) : ![quad.png](https://archive.blender.org/developer/F702951/quad.png) ![island.png](https://archive.blender.org/developer/F702953/island.png) **The big question is :** is this method the only possible one to allow fast enough responsiveness or can a better one be developed and work in real-time ? Since this feature [came out in 2.49 ](https://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.49/Projection_Paint) I'm **guessing** the modern computers can handle a better method. What do you think b3d devs ?

Antonis Ryakiotakis was assigned by ChameleonScales

2017-08-19 11:46:49 +02:00

ChameleonScales commented

2017-08-19 11:53:40 +02:00

I assigned you because you were assigned to this one https://developer.blender.org/T43709. It may be the same issue but I'd like to know if you have an answer to my question above.

Ryan Pocock commented

2017-08-19 18:02:09 +02:00

more information:

System Information
Linux Manjaro 64-bit
GeForce GT 640

Blender Version
Broken: 2.79 RC1 down to 2.76
Worked: 2.75a and previous versions

Short description of error

Up until 2.75a, the texture brush bleed performed on quads using the bisectors of the quads :

but since 2.76 up until 2.79 RC1, it performs on the triangles that compose the quads :

this brought undesirable results such as an uneven thickness of the bleeding :

increasing the bleed value is not a good way to counteract this problem since it increases the chances of bleeding into another UV island or bleeding inside the very island we're painting in, as shown by the white arrows here (a texture stencil was used in the brush to make it visible everywhere) :

Exact steps for others to reproduce the error:

in 2.75a open this file and click on the cube to fill it with paint with the fill brush
observe the image

do the same in any later version

more information: System Information Linux Manjaro 64-bit GeForce GT 640 Blender Version Broken: 2.79 RC1 down to 2.76 Worked: 2.75a and previous versions Short description of error Up until 2.75a, the texture brush bleed performed on quads using the bisectors of the quads : [[http://i.imgur.com/LVDLwXg.png]] but since 2.76 up until 2.79 RC1, it performs on the triangles that compose the quads : [[http://i.imgur.com/9kR3tpO.png]] this brought undesirable results such as an uneven thickness of the bleeding : [[http://i.imgur.com/8W2Ar3P.png]] increasing the bleed value is not a good way to counteract this problem since it increases the chances of bleeding into another UV island or bleeding inside the very island we're painting in, as shown by the white arrows here (a texture stencil was used in the brush to make it visible everywhere) : [[http://i.imgur.com/hEcBYFU.png]] Exact steps for others to reproduce the error: - in 2.75a open this file and click on the cube to fill it with paint with the fill brush - observe the image # do the same in any later version

Bastien Montagne commented

2017-08-19 18:31:13 +02:00

Added subscriber: @brecht

Antonis Ryakiotakis was unassigned by Bastien Montagne

2017-08-19 18:35:42 +02:00

Bastien Montagne commented

2017-08-19 18:35:42 +02:00

Added subscriber: @Psy-Fi

Bastien Montagne commented

2017-08-19 18:35:42 +02:00

No point in keeping twice the same report open…

Also, @ChameleonScales, please avoid doing triaging tasks yourself unless you know what you are doing, @Psy-Fi is not currently active and doubt he will handle bug reports currently!

No point in keeping twice the same report open… Also, @ChameleonScales, please avoid doing triaging tasks yourself unless you know what you are doing, @Psy-Fi is not currently active and doubt he will handle bug reports currently!

ChameleonScales commented

2017-08-19 19:17:24 +02:00

ok, sorry for that.

Jaufré Aligé commented

2018-07-23 18:26:18 +02:00

Added subscriber: @Jau

Jaufré Aligé commented

2018-07-23 18:26:18 +02:00

Hello,

Any news about this ? This functionality is useless this way, which is catastrophic when you need to paint a mask (ex : before exporting to Unreal Engine)

Hello, Any news about this ? This functionality is useless this way, which is catastrophic when you need to paint a mask (ex : before exporting to Unreal Engine)

Nathanael commented

2018-08-16 13:50:44 +02:00

Added subscribers: @ideasman42, @pk-nb

Nathanael commented

2018-08-16 13:50:44 +02:00

Hi there—I wanted to let you know I took at a look at this bug. I ran into this issue originally when going through the blender cloud game asset tutorials. There are a couple things going on here in the latest blender. I was able to fix one miscalculation for tris but ran into a blocker with quads.

I believe the source of this bug is from the change to move to tri-data only within source/blender/editors/sculpt_paint/paint_image_proj.c. Specifically, this diff https://developer.blender.org/rBS416d164fecae8aeaa035c3bc2d47f7c07c970e48 from @campbellbarton.

For the miscalculation with tris: it appears the bleed calculation was incorrectly using the edge normal with an edge rather than using a point normal. You can compare the difference with the patch and blend file provided here. Both are set to a bleed of 16px.

uv_patch.patch
problem-bleed.blend

Note that I fixed the "sawtooth" and corrected the bleed amount by fixing the normal calculation. Unfortuantely, there is still tri overextension for quads as you can see with the following screenshots.

After this change I realized it seems impossible to calculate the proper bleed for quads with tri-data alone. It seems like the bleed calculation is just different for quads and tri. Unfortunately with the change made from that diff we no longer have the quad info. I'm hoping for context for the change but I fear to fix this will require a revert back to using special cases for quads or else find another way to calculate bleed. My guess is that this was a refactor. Thanks for looking at this, and hopefully this helps!

Hi there—I wanted to let you know I took at a look at this bug. I ran into this issue originally when going through the [blender cloud game asset tutorials](https://cloud.blender.org/p/game-asset-creation/56041551044a2a00d0d7e09a). There are a couple things going on here in the latest blender. I was able to fix one miscalculation for tris but ran into a blocker with quads. I believe the source of this bug is from the change to move to tri-data only within `source/blender/editors/sculpt_paint/paint_image_proj.c`. Specifically, this diff https://developer.blender.org/rBS416d164fecae8aeaa035c3bc2d47f7c07c970e48 from @campbellbarton. For the miscalculation with tris: it appears the bleed calculation was incorrectly using the edge normal with an edge rather than using a point normal. You can compare the difference with the patch and blend file provided here. Both are set to a bleed of 16px. [uv_patch.patch](https://archive.blender.org/developer/F4246417/uv_patch.patch) [problem-bleed.blend](https://archive.blender.org/developer/F4246632/problem-bleed.blend) ![Screen Shot 2018-08-16 at 7.35.52 AM.png](https://archive.blender.org/developer/F4246607/Screen_Shot_2018-08-16_at_7.35.52_AM.png) ![Screen Shot 2018-08-16 at 7.38.11 AM.png](https://archive.blender.org/developer/F4246610/Screen_Shot_2018-08-16_at_7.38.11_AM.png) Note that I fixed the "sawtooth" and corrected the bleed amount by fixing the normal calculation. Unfortuantely, there is still tri overextension for quads as you can see with the following screenshots. ![Screen Shot 2018-08-16 at 7.36.14 AM.png](https://archive.blender.org/developer/F4246618/Screen_Shot_2018-08-16_at_7.36.14_AM.png) ![Screen Shot 2018-08-16 at 7.38.51 AM.png](https://archive.blender.org/developer/F4246621/Screen_Shot_2018-08-16_at_7.38.51_AM.png) After this change I realized it seems impossible to calculate the proper bleed for quads with tri-data alone. It seems like the bleed calculation is just different for quads and tri. Unfortunately with the change made from that diff we no longer have the quad info. I'm hoping for context for the change but I fear to fix this will require a revert back to using special cases for quads or else find another way to calculate bleed. My guess is that this was a refactor. Thanks for looking at this, and hopefully this helps!

Daniel Cañizares commented

2018-12-03 03:28:02 +01:00

Added subscriber: @dacanizares