Maniphest T22782

Solidify Thickness negative and positive values are the same result
Closed, Resolved
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Assigned To
Campbell Barton (campbellbarton)
Authored By
Ed Britton (figbash)
Jul 8 2010, 1:07 AM
Tags
  • Modifiers
  • BF Blender
Subscribers
Campbell Barton (campbellbarton)
Ed Britton (figbash)
Shinsuke Irie (irie)

Description

Create a plane
Add a solidify modifier to it
Adjust solidifer thickness value to position 1, then -1, notice that both cause thickness on both sides of the plane.

Using a much earlier release of blender 2.5 (built on 1/5/2010) the solidify modifier has the expected result of negative thickness extruding to the inside and positive thickness extruding to the outside. Currently the modifier is more like a fatten function :)

This might not seem like a big deal but it's really hurting my productivity, I would deeply appreciate a fix to it!

Tested on:
svn 3009, Windows XP

Event Timeline

Ed Britton (figbash) edited a custom field.Jul 8 2010, 1:07 AM
Campbell Barton (campbellbarton) added a comment.Jul 8 2010, 5:13 PM

I think this is not a bug since I spent some time to make it work this way.

Negative thickness is intended to be used with the offset option since it can give quite flexible results with way.

Can you show an image of what was possible before which is not possible now?

Ed Britton (figbash) added a comment.Jul 8 2010, 7:08 PM

Ah, setting the offset to 1 does what I'm expecting it to do. I guess it is a clarity issue, as there is no tooltip on Offset (at least on my build).
Personally I think a tooltip explaining it and a default of 1 would be useful, as to me an offset of 0 suggests that the original faces wouldn't move when changing thickness, since that feels like I'm offsetting them.
My issue was simply the original faces moving, as every single case of my using solify is too add thickness to things like armor or bracelets, where the original faces are already perfectly positioned on the body.
Sorry, it's obviously not a bug and I see the usefulness of the feature now, I just feel it needs more explanation :)

Campbell Barton (campbellbarton) added a comment.Jul 14 2010, 10:25 AM

Your right, its not too clear, updated the tooltip: "Offset the thickness from the center".
Changed default offset to -1.0 based on your feedback.

Campbell Barton (campbellbarton) changed the task status from Unknown Status to Resolved.Jul 14 2010, 10:25 AM
Shinsuke Irie (irie) added a comment.May 13 2012, 11:16 AM

I expected the following result.

Positive thickness:

- outer surface is original face
- inner surface is new one
- normals of the surfaces point to the outside

. air
.
. |
.--------------- orig
.
.--------------- new
. |
.
. object

Negative thickness:

- inner surface is original face
- outer surface is new one
- normals of the surfaces point to the inside

. air
.
.--------------- new
. |
.
. |
.--------------- orig
.
. object

I think such a normal-flipped result of the negative thickness is very useful for rendering the MikuMikuDance-like toon edges.

See my test movie:

http://www.youtube.com/watch?v=mhNiBBgfyOs&feature=youtu.be&a

To render this movie, I modified MOD_solidify.c not to swap the inner and outer surfaces even if the thickness is negative. Otherwise, I had to flip all normals of the objects before adding the solidify modifier.

Also, if the negative thickness works as I intend, we can use realtime toon edges in the game engine by applying the solidify modifier.

Shinsuke Irie (irie) added a comment.May 13 2012, 11:50 AM

I just posted patches for changing the behavior of the negative thickness as I said in my previous comment:

http://projects.blender.org/tracker/index.php?func=detail&aid=31444&group_id=9&atid=127

Campbell, can you test my patch and smaple .blend file? Don't you think this change is useful?