Some kind of bug ? or am stoopid ! ( mebe i am :P )

hi all
here’s the thing:
simple render basic UVing…
and i got this:

and… this and that !!!

WTF !!! this sux !!!

i bet i did something wrong !!! and i’d really be happy someone kik my butt !!! :smiley:
on one thing i missed…

here’s the blend file:
tour_st_sernin-44.blend (1.5 MB)

does NE1 have an idea of what’s going vrong ? it’s just a damn simple mesh !!!
am not an expert but am not a noob… knowing about normals and geometric basis for dig image rendering…
but atm, i got no idea why this fux up :confused:
please gimme your advices :slight_smile:

Looks like an normals issue. Or maybe you have overlapping geometry. Do you use boolean modifiers?

hi habauk :slight_smile:

nope.
no normals prob, no overlapping… and no boolean ( they never work :stuck_out_tongue: lol )

plz get the blend and try it out and gimme the result in a post :slight_smile:
i hope it’s my bad but i see no reason :confused:

I don’t see any geometry or normals issues. It could be a material problem, as textures aren’t included, it’s hard to tell for sure.

Just checked the file, I assume its a problem with your baked AO map (maps are not included in your file). Using the AO shader, I can reproduce some very small artefacts in those areas.

oww… okay.
lemme give u all !!!
some few minutes :stuck_out_tongue:

meh :(( file too big !!!

i be bak soon with some zipped file :slight_smile:

thx for you help guys !!!

finally the textures have nothing to do with this problem. I noticed the AO node changes some things…

Also, i moved the mesh away from the place it is and i noticed this problem disappears.
And playing with various things, showed it looks like some normal interpolation problem :confused:
tied to sharp edges…

an of course it appears on my baked AO map :frowning:

Mebe it comes from my blender prefs ? or from my machine ? ( graphic drivers )
i gonna try this blend on another machine just to see.

EDIT: well :frowning: bad news this happens on my other machine !
i tried to open the file with blender 2.79b and the problem disappears ( but 2.79b
don’t have the AO node that i need… )
therefore it appears to be some kind of bug in the 2.79 up to date builds.
maybe i should file a bug report ?

here’s a simplified version of the file, with simple nodes material and no textures.
bug.blend (1.2 MB)

please could someone try to open it with the blender-2.79.0-git.001414fb2f73-windows64 located here: https://builder.blender.org/download/blender-2.79-001414fb2f73-win64.zip
and confirm me the problem exists ?

thanks in advance :slight_smile:

Okay :))

now i know it’s a bug :stuck_out_tongue:

an accuracy problem in cycles unable to interpolate normals when far from 0:0:0 coords

( to be honest it’s a noob programmer’s prob :stuck_out_tongue: floating point accuracy is too short… well… i do not code anymore then i shut my mouth ! )

the case… we could say it is close as it do not depends on some tech but on some software limits…
BA Forum can do noting about this…
Note that it’s not a bug but a floating point accuracy limit problem ^^

regards and have fun with limits :stuck_out_tongue:

Happy blending !