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normal pass bug
Closed, ResolvedPublic

Description

System Information
windows7 64
ASUS ATI Radeon HD6870

Blender Version
Broken: (All)
Worked: (None)

Short description of error




Exact steps for others to reproduce the error

open, render - we will not see difference betweel inside and outside normals

Event Timeline

Alexey (Inwader77) set Type to Bug.
Alexey (Inwader77) created this task.
Alexey (Inwader77) raised the priority of this task from to Needs Triage by Developer.
Bastien Montagne (mont29) triaged this task as Confirmed, Medium priority.

Looks like render is systematically double-sided (in both BI and Cycles)… UI tip of 'double sided' option in Normals panel of Mesh properties implies that it affects 3DView (OpenGL) and rendering, which is obviously not the case.

@Sergey Sharybin (sergey), @Campbell Barton (campbellbarton), do you know whether being always double-sided in rendering is expected behavior (in which case we just have to fix the tooltip, much simpler :P )?

@Bastien Montagne (mont29), BI was never checking for ME_TWOSIDED flag as far as i can see up to 2.42 versions. So think changing tooltip is safest idea here, because otherwise it'll just break quite some setups.

@Alexey (Inwader77) So, thanks for the report, but no bug here really, render engines have always been rendering in 'double sided' mode (i.e. they behave as if faces always had both inward and outward normals).

@Alexey (Inwader77) So, thanks for the report, but no bug here really, render engines have always been rendering in 'double sided' mode (i.e. they behave as if faces always had both inward and outward normals).

Ok, how i can work with front/back side of face? we have not this function nowhere. How i can cut backface in render(like in 3d view)?

Think this simply not possible.

Alexey (Inwader77) added a comment.EditedJul 14 2015, 10:00 PM

Think this simply not possible.

We must add this function, because if we create this сut sphere, create plane, bake norm map


use this norm map for plane
render and look on normal pass - we will see proper result

blender can distinguishes inward and outward sides

Improvements are always possible, but they're happening outside of the bug tracker.

Improvements are always possible, but they're happening outside of the bug tracker.

Ok, where can I do it

Improvements are always possible, but they're happening outside of the bug tracker.