Hi,
Create a Torus and a light, Render…
Why get hard result even with smooth normal ?
Hard render result with smooth normal
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- jerry7
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- tamte
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that's quite common artifact when having low poly geo with interpolated normal and sending rays (shadow, reflection, etc), since they still intersect the low poly geo
in your case it's mostly raytrace shadows, to get rid of that you better have higher res geo or render as subdivision surface
in your case it's mostly raytrace shadows, to get rid of that you better have higher res geo or render as subdivision surface
Tomas Slancik
FX Supervisor
Method Studios, NY
FX Supervisor
Method Studios, NY
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ah - yes - I had a closer look and its the shadows that is causing the blackness.
Try increasing the Ray bias to 0.3 in Mantra / Properties / Shading to push the shadow away. Turning off shadows in the light will also solve it.
Edit - just tested the torus in AtomKraft(3delight) and the same results - ray traced bias ‘fixes’ the shadow. Edit2: Nuke's Scanline also needs the fix
Try increasing the Ray bias to 0.3 in Mantra / Properties / Shading to push the shadow away. Turning off shadows in the light will also solve it.
Edit - just tested the torus in AtomKraft(3delight) and the same results - ray traced bias ‘fixes’ the shadow. Edit2: Nuke's Scanline also needs the fix
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hi, MartybNz
From your sample scene, I know the reason for hard shading is Self Shadow with Double side.
If I use Backface Removal ,the shadow detached from object's intersection that can't be accepted for product.
If I don't Backface Removal , the shadow border not smooth.
If I close self shadow as you sample scene, the final result is not be accepted for some scene that need selfshadow.
So ,I have no idea about it now!
PS: even I increase segment , shadow border is still jagged.
From your sample scene, I know the reason for hard shading is Self Shadow with Double side.
If I use Backface Removal ,the shadow detached from object's intersection that can't be accepted for product.
If I don't Backface Removal , the shadow border not smooth.
If I close self shadow as you sample scene, the final result is not be accepted for some scene that need selfshadow.
So ,I have no idea about it now!
PS: even I increase segment , shadow border is still jagged.
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Good times reading up on this very cool area of shadowing.
It boils down to when a polygon/primitive is orthogonal to the light and can be declared a backface, i.e. the normal facing away from the light. The option to backface cull in Houdini appears to apply to lights as well as the camera. A combination of this and bias is the favoured solution to getting rid of it.
In gaming it's known as Projective Aliasing.
http://msdn.microsoft.com/en-us/library/windows/desktop/ee416324(v=vs.85).aspx [msdn.microsoft.com]
Blender's Cycles has it and Nuke's Scanline Percentage Closer Filtering shadows can use a bias slope control that will ‘hide’ this visual artefact more gracefully than a pure bias control. It appears to be simply luck that SI/Max MR don't show the issues, though, can't actually test it here see what is really going on under different conditions. The MR defaults in Maya 2014 certainly show issues.
Ah, and floating shadows is called ‘Peter Panning’
It boils down to when a polygon/primitive is orthogonal to the light and can be declared a backface, i.e. the normal facing away from the light. The option to backface cull in Houdini appears to apply to lights as well as the camera. A combination of this and bias is the favoured solution to getting rid of it.
In gaming it's known as Projective Aliasing.
http://msdn.microsoft.com/en-us/library/windows/desktop/ee416324(v=vs.85).aspx [msdn.microsoft.com]
Blender's Cycles has it and Nuke's Scanline Percentage Closer Filtering shadows can use a bias slope control that will ‘hide’ this visual artefact more gracefully than a pure bias control. It appears to be simply luck that SI/Max MR don't show the issues, though, can't actually test it here see what is really going on under different conditions. The MR defaults in Maya 2014 certainly show issues.
Ah, and floating shadows is called ‘Peter Panning’
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