Inclusive bounds for VertexWeightEdit? #82831

New Issue

Will · 2020-11-19T01:23:34+01:00

Will commented

2020-11-19 01:23:34 +01:00

System Information
Operating system: Linux
Graphics card: Intel UHD

Blender Version
Broken: 2.90.1
Worked: ???

Short description of error

The "Group Add" "Threshold" for the VertexWeightEdit modifier seems to be interpreted as an exclusive bound. This may be a deliberate design choice, but it makes it impossible to assign default weights of zero:

Exact steps for others to reproduce the error
When dealing with output from generative modifiers or meshes linked from library .blend files, it's useful for me to be able to non-destructively assign a default vertex weight of 0.0 to all vertices so I can then use VertexWeightMix modifiers to add textures to the weights, combine multiple vertex groups, etc.

What I was trying to say was that the VertexWeightEdit modifier has a "Group Add" functionality for setting all weights above a threshold, but it doesn't do anything for weights that are exactly equal to that threshold:

This kinda makes sense, but it also makes it impossible to e.g. assign weights of 0.0, or only weights of exactly 1.0.

Blend file below. The threshold is 0.010, so set the "Default Weight" to 0.010 and 0.011 to see what I mean.

VertexWeightEdit_Bounds.blend

Maybe this file makes it a bit clearer:

I have added a second vertexgroup and a VertexWeightMix modifier after the VertexWeightEdit modifier
none of the vertices are in the first group per se
the VertexWeightEdit modifier tries to add all vertices to the group with a value of 0.0 (to be able to be used by the following VertexWeightMix modifier), but "fails" due to the exclusive bounds

VertexWeightEdit_Bounds_repro.blend

**System Information** Operating system: Linux Graphics card: Intel UHD **Blender Version** Broken: 2.90.1 Worked: ??? **Short description of error** The "Group Add" "Threshold" for the VertexWeightEdit modifier seems to be interpreted as an exclusive bound. This may be a deliberate design choice, but it makes it impossible to assign default weights of zero: ![image.png](https://archive.blender.org/developer/F9320317/image.png) ![image.png](https://archive.blender.org/developer/F9320319/image.png) **Exact steps for others to reproduce the error** When dealing with output from generative modifiers or meshes linked from library .blend files, it's useful for me to be able to non-destructively assign a default vertex weight of 0.0 to all vertices so I can then use VertexWeightMix modifiers to add textures to the weights, combine multiple vertex groups, etc. What I was trying to say was that the VertexWeightEdit modifier has a "Group Add" functionality for setting all weights above a threshold, but it doesn't do anything for weights that are exactly equal to that threshold: ![image.png](https://archive.blender.org/developer/F9341342/image.png) ![image.png](https://archive.blender.org/developer/F9341344/image.png) This kinda makes sense, but it also makes it impossible to e.g. assign weights of 0.0, or only weights of exactly 1.0. Blend file below. The threshold is 0.010, so set the "Default Weight" to 0.010 and 0.011 to see what I mean. [VertexWeightEdit_Bounds.blend](https://archive.blender.org/developer/F9341371/VertexWeightEdit_Bounds.blend) Maybe this file makes it a bit clearer: - I have added a second vertexgroup and a `VertexWeightMix` modifier after the `VertexWeightEdit` modifier - none of the vertices are in the first group per se - the `VertexWeightEdit` modifier tries to add all vertices to the group with a value of 0.0 (to be able to be used by the following `VertexWeightMix` modifier), but "fails" due to the exclusive bounds [VertexWeightEdit_Bounds_repro.blend](https://archive.blender.org/developer/F9791525/VertexWeightEdit_Bounds_repro.blend)

Will commented

2020-11-19 01:23:34 +01:00

Added subscriber: @WCN

Will commented

2020-11-19 01:39:34 +01:00

I just realized my screenshots don't actually prove anything, as zero weights would be rendered black anyway. But the behaviour I described does occur AFAICT, and the test I did produces the same result with non-zero thresholds and default weights.

Germano Cavalcante commented

2020-11-19 19:59:09 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2020-11-19 19:59:09 +01:00

I'm not sure what I'm seeing in the image.
Can you share the file so we can analyze it?

I'm not sure what I'm seeing in the image. Can you share the file so we can analyze it?

Germano Cavalcante commented

2020-11-20 15:40:29 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Will commented

2020-11-21 00:39:00 +01:00

@mano-wii Hey, sorry for being unclear.

What I was trying to say was that the VertexWeightEdit modifier has a "Group Add" functionality for setting all weights above a threshold, but it doesn't do anything for weights that are exactly equal to that threshold:

This kinda makes sense, but it also makes it impossible to e.g. assign weights of 0.0, or only weights of exactly 1.0.

Blend file below. The threshold is 0.010, so set the "Default Weight" to 0.010 and 0.011 to see what I mean.

VertexWeightEdit_Bounds.blend

@mano-wii Hey, sorry for being unclear. What I was trying to say was that the VertexWeightEdit modifier has a "Group Add" functionality for setting all weights above a threshold, but it doesn't do anything for weights that are exactly equal to that threshold: ![image.png](https://archive.blender.org/developer/F9341342/image.png) ![image.png](https://archive.blender.org/developer/F9341344/image.png) This kinda makes sense, but it also makes it impossible to e.g. assign weights of 0.0, or only weights of exactly 1.0. Blend file below. The threshold is 0.010, so set the "Default Weight" to 0.010 and 0.011 to see what I mean. [VertexWeightEdit_Bounds.blend](https://archive.blender.org/developer/F9341371/VertexWeightEdit_Bounds.blend)

Germano Cavalcante commented

2020-12-04 17:09:58 +01:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Richard Antalik commented

2020-12-07 08:12:19 +01:00

Added subscriber: @iss

Richard Antalik commented

2020-12-07 08:12:19 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Richard Antalik commented

2020-12-07 08:12:19 +01:00

I can confirm this is the case, but I am not sure why you need this. Though I have not so much experience in this area.
Can you explain how this is problem in workflow?

I can confirm this is the case, but I am not sure why you need this. Though I have not so much experience in this area. Can you explain how this is problem in workflow?

Will commented

2020-12-15 07:37:52 +01:00

@iss When dealing with output from generative modifiers or meshes linked from library .blend files, it's useful for me to be able to non-destructively assign a default vertex weight of 0.0 to all vertices so I can then use VertexWeightMix modifiers to add textures to the weights, combine multiple vertex groups, etc.

@iss When dealing with output from generative modifiers or meshes linked from library `.blend` files, it's useful for me to be able to non-destructively assign a default vertex weight of 0.0 to all vertices so I can then use VertexWeightMix modifiers to add textures to the weights, combine multiple vertex groups, etc.

Philipp Oeser commented

2021-02-11 09:52:48 +01:00

Changed status from 'Needs User Info' to: 'Needs Triage'

Philipp Oeser commented

2021-02-11 10:21:35 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-02-11 10:21:35 +01:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Philipp Oeser commented

2021-02-11 10:21:35 +01:00

I think I get the point.
So for vertices not in the group, it is impossible to add them with a default value of 0.0.

Maybe this file makes it a bit clearer:

I have added a second vertexgroup and a VertexWeightMix modifier after the VertexWeightEdit modifier
none of the vertices are in the first group per se
the VertexWeightEdit modifier tries to add all vertices to the group with a value of 0.0 (to be able to be used by the following VertexWeightMix modifier), but "fails" due to the exclusive bounds

VertexWeightEdit_Bounds_repro.blend

This patch changes it to be inclusive bounds

P1959: T82831_snippet

diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index 7209d17735a..9483cadc93b 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -5169,7 +5169,7 @@ static void rna_def_modifier_weightvgedit(BlenderRNA *brna)
   RNA_def_property_ui_range(prop, 0.0, 1.0, 1, -1);
   RNA_def_property_ui_text(prop,
                            "Add Threshold",
-                           "Lower bound for a vertex's weight "
+                           "Lower (inclusive) bound for a vertex's weight "
                            "to be added to the vgroup");
   RNA_def_property_update(prop, 0, "rna_Modifier_update");
 
@@ -5179,7 +5179,7 @@ static void rna_def_modifier_weightvgedit(BlenderRNA *brna)
   RNA_def_property_ui_range(prop, 0.0, 1.0, 1, -1);
   RNA_def_property_ui_text(prop,
                            "Remove Threshold",
-                           "Upper bound for a vertex's weight "
+                           "Upper (inclusive) bound for a vertex's weight "
                            "to be removed from the vgroup");
   RNA_def_property_update(prop, 0, "rna_Modifier_update");
 
diff --git a/source/blender/modifiers/intern/MOD_weightvg_util.c b/source/blender/modifiers/intern/MOD_weightvg_util.c
index c5e2ecb9660..b28af1e155c 100644
--- a/source/blender/modifiers/intern/MOD_weightvg_util.c
+++ b/source/blender/modifiers/intern/MOD_weightvg_util.c
@@ -326,7 +326,7 @@ void weightvg_update_vg(MDeformVert *dvert,
 
     /* If the vertex is in this vgroup, remove it if needed, or just update it. */
     if (dw != NULL) {
-      if (do_rem && w < rem_thresh) {
+      if (do_rem && w <= rem_thresh) {
         BKE_defvert_remove_group(dv, dw);
       }
       else {
@@ -334,7 +334,7 @@ void weightvg_update_vg(MDeformVert *dvert,
       }
     }
     /* Else, add it if needed! */
-    else if (do_add && w > add_thresh) {
+    else if (do_add && w >= add_thresh) {
       BKE_defvert_add_index_notest(dv, defgrp_idx, w);
     }
   }

This is certainly not a bug, but possibly a TODO (if this is really beneficial in all cases).
Will confirm for now and let modules make a decision here.

I think I get the point. So for vertices not in the group, it is impossible to add them with a default value of 0.0. Maybe this file makes it a bit clearer: - I have added a second vertexgroup and a `VertexWeightMix` modifier after the `VertexWeightEdit` modifier - none of the vertices are in the first group per se - the `VertexWeightEdit` modifier tries to add all vertices to the group with a value of 0.0 (to be able to be used by the following `VertexWeightMix` modifier), but "fails" due to the exclusive bounds [VertexWeightEdit_Bounds_repro.blend](https://archive.blender.org/developer/F9791525/VertexWeightEdit_Bounds_repro.blend) This patch changes it to be inclusive bounds [P1959: T82831_snippet](https://archive.blender.org/developer/P1959.txt) ```Diff diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c index 7209d17735a..9483cadc93b 100644 --- a/source/blender/makesrna/intern/rna_modifier.c +++ b/source/blender/makesrna/intern/rna_modifier.c @@ -5169,7 +5169,7 @@ static void rna_def_modifier_weightvgedit(BlenderRNA *brna) RNA_def_property_ui_range(prop, 0.0, 1.0, 1, -1); RNA_def_property_ui_text(prop, "Add Threshold", - "Lower bound for a vertex's weight " + "Lower (inclusive) bound for a vertex's weight " "to be added to the vgroup"); RNA_def_property_update(prop, 0, "rna_Modifier_update"); @@ -5179,7 +5179,7 @@ static void rna_def_modifier_weightvgedit(BlenderRNA *brna) RNA_def_property_ui_range(prop, 0.0, 1.0, 1, -1); RNA_def_property_ui_text(prop, "Remove Threshold", - "Upper bound for a vertex's weight " + "Upper (inclusive) bound for a vertex's weight " "to be removed from the vgroup"); RNA_def_property_update(prop, 0, "rna_Modifier_update"); diff --git a/source/blender/modifiers/intern/MOD_weightvg_util.c b/source/blender/modifiers/intern/MOD_weightvg_util.c index c5e2ecb9660..b28af1e155c 100644 --- a/source/blender/modifiers/intern/MOD_weightvg_util.c +++ b/source/blender/modifiers/intern/MOD_weightvg_util.c @@ -326,7 +326,7 @@ void weightvg_update_vg(MDeformVert *dvert, /* If the vertex is in this vgroup, remove it if needed, or just update it. */ if (dw != NULL) { - if (do_rem && w < rem_thresh) { + if (do_rem && w <= rem_thresh) { BKE_defvert_remove_group(dv, dw); } else { @@ -334,7 +334,7 @@ void weightvg_update_vg(MDeformVert *dvert, } } /* Else, add it if needed! */ - else if (do_add && w > add_thresh) { + else if (do_add && w >= add_thresh) { BKE_defvert_add_index_notest(dv, defgrp_idx, w); } } ``` This is certainly not a bug, but possibly a TODO (if this is really beneficial in all cases). Will confirm for now and let modules make a decision here.

Philipp Oeser removed the

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Inclusive bounds for VertexWeightEdit? #82831