Curve Falloff Issue with Mask Painting for Flood Fill #42984

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Leon Cheung · 2014-12-22T10:59:43+01:00

Leon Cheung commented

2014-12-22 10:59:43 +01:00

System Information
Windows 8.1 64bit | GTX680

Blender Version
Broken: 2.72.3 071ec91

Short description of error
Some curve falloff preset doesn't work well with mask painting for flood fill.

Exact steps for others to reproduce the error
Please see this video . (P.S.: As tested, problematic typs are SMOOTH and SHARP)

Thank you.

plane_sculpt.blend

**System Information** Windows 8.1 64bit | GTX680 **Blender Version** Broken: 2.72.3 071ec91 **Short description of error** Some curve falloff preset doesn't work well with mask painting for flood fill. **Exact steps for others to reproduce the error** Please see [this video ](http://youtu.be/vj4JNIfeyiA). (P.S.: As tested, problematic typs are **SMOOTH** and **SHARP**) Thank you. [plane_sculpt.blend](https://archive.blender.org/developer/F133129/plane_sculpt.blend)

Leon Cheung commented

2014-12-22 10:59:44 +01:00

Changed status to: 'Open'

Leon Cheung commented

2014-12-22 10:59:44 +01:00

Added subscriber: @ZhangYu

Antonis Ryakiotakis was assigned by Sergey Sharybin

2014-12-22 14:01:32 +01:00

Sergey Sharybin commented

2014-12-22 14:01:32 +01:00

Added subscribers: @Psy-Fi, @Sergey

Sergey Sharybin commented

2014-12-22 14:01:32 +01:00

@Psy-Fi, can i put this one onto your list? :)

Antonis Ryakiotakis commented

2014-12-26 20:22:21 +01:00

Changed status from 'Open' to: 'Archived'

Antonis Ryakiotakis closed this issue

2014-12-26 20:22:21 +01:00

Antonis Ryakiotakis commented

2014-12-26 20:22:21 +01:00

This is expected behaviour and is caused due to those brush falloffs not painting the vertices up to the threshold that cuts a face off from being subdivided. Also solid shading makes it difficult to see what is really happening here because it doesn't display the individual vertex masks (even though they still get used for the algorithm). To avoid that you can increase the brush strength beyond 1.0 (it's allowed if you type in the value) or use lasso/box selection.

Leon Cheung commented

2014-12-28 18:01:35 +01:00

I can see it is expected. However, the algorithm for "Auto Handle" makes somewhere on the lower curve below zero, so when painting mask in Invert Mask mode (I mean first Alt M, then Ctrl I), a negative value contributes a positive influence (a very tiny one in the above case, for the default Smoothand Sharp curve preset), for Mask brush, this kind of opposite influence becomes more obvious.

IMHO, solutions are:

Improve algorithm for Auto Handle to avoid nagative value generated in interpolation segments;
For Smoothand Sharp presets, Change the type of the bottom-right control point (x=1.00000, y=0.00000) from Auto Handle to "Vector Handle", which will solve this "annoying" influence in this case.
Implement a clamp range for Mask brush, to force the valid value range from 0 to 1.

Btw, I've tried the two ways that you've suggested, "to incease brush strengh beyond 1.0" will not solve the problem in Invert Mask mode, but exaggerate it. As for the lasso/box selection, the back faces are also selected, even though the Front Faces Only is toggled (a possible bug?).

Please correct me if I'm wrong here. Thank you...

I can see it is expected. However, the algorithm for "Auto Handle" makes somewhere on the lower curve below zero, so when painting mask in **Invert Mask** mode (I mean first Alt M, then Ctrl I), a negative value contributes a positive influence (a very tiny one in the above case, for the default **Smooth**and **Sharp** curve preset), for Mask brush, this kind of opposite influence becomes more obvious. ![curve.png](https://archive.blender.org/developer/F134054/curve.png) IMHO, solutions are: 1. Improve algorithm for Auto Handle to avoid nagative value generated in interpolation segments; 2. For **Smooth**and **Sharp** presets, Change the type of the bottom-right control point (x=1.00000, y=0.00000) from **Auto Handle** to "Vector Handle", which will solve this "annoying" influence in this case. 3. Implement a clamp range for Mask brush, to force the valid value range from 0 to 1. Btw, I've tried the two ways that you've suggested, "to incease brush strengh beyond 1.0" will not solve the problem in Invert Mask mode, but exaggerate it. As for the lasso/box selection, the back faces are also selected, even though the **Front Faces Only** is toggled (a possible bug?). Please correct me if I'm wrong here. Thank you...

Antonis Ryakiotakis commented

2014-12-28 18:08:28 +01:00

Unfortunately, box and lasso are meant to work like that too.

I agree about the clamping of the curve but I suspect it is a separate issue.

Unfortunately, box and lasso are meant to work like that too. I agree about the clamping of the curve but I suspect it is a separate issue.

Antonis Ryakiotakis commented

2014-12-28 21:30:34 +01:00

Changed status from 'Archived' to: 'Open'

Antonis Ryakiotakis reopened this issue

2014-12-28 21:30:34 +01:00

Antonis Ryakiotakis commented

2014-12-28 21:30:34 +01:00