SoPostEffectAmbientOcclusion¶
-
InventorModule
¶ author MeVis Medical Solutions AG
package MeVisLab/Standard
dll SoRenderers
definition SoRenderers.def
Purpose¶
- The
SoPostEffectAmbientOcclusion
module offers screen space ambient occlusion (SSAO) for the SoPostEffectRenderer
module.
This module only works on opaque geometry, so it should be placed before any
transparent geometry rendered by SoPostEffectAdditionalGeometry
modules.
It makes use of the depth and normal buffers to calculate the ambient occlusion in screen space.
Details¶
The algorithm contains various parameters, the best setting for the parameter highly depends on the concrete geometry that is rendered.
Example screenshots:
Normal Rendering:

With Screen Space Ambient Occlusion turned on:

Only the ambient occlusion term:

Parameter Fields¶
Field Index¶
Angle Bias : Float |
Mode (mode) : Enum |
Show Ambient Only : Bool |
Attenuation : Float |
Mode (blurMode) : Enum |
|
Contrast : Float |
Num. Directions : Integer |
|
debugTextures : Bool |
Num. Steps : Integer |
|
Enable : Bool |
Radius : Float |
|
Enabled : Bool |
Sample Radius : Float |
|
Half resolution ambient occlusion : Bool |
Scale : Float |
|
Intensity : Float |
Sharpness : Float |
Visible Fields¶
Angle Bias¶
-
name:
ambientAngleBias
, type:
Float
, default:
30
, minimum:
0
, maximum:
60
¶ Sets an angle threshold.
All angles below this threshold (in degrees) will be discarded when calculating ambient occlusion.
Thus, the higher this value, the less self-occlusion will occur. The optimal value for this parameter depends on the coarseness of the triangle mesh: the coarser the mesh, the greater the bias should be.
Sample Radius¶
-
name:
ambientSampleRadius
, type:
Float
, default:
30
¶ Sets the radius of the SSAO sampling.
Intensity¶
-
name:
ambientIntensity
, type:
Float
, default:
8
, minimum:
0.1
, maximum:
16
¶ Sets the intensity of the ambient occlusion.
Scale¶
-
name:
ambientScale
, type:
Float
, default:
0.1
, minimum:
0.0001
, maximum:
1
¶ Sets a scaling factor for the distance term of the algorithm; lower values produce more occlusion.
Num. Directions¶
Num. Steps¶
Attenuation¶
Contrast¶
Half resolution ambient occlusion¶
-
name:
useLowResAO
, type:
Bool
, default:
FALSE
¶ If checked, the SSAO calculation and blur pass is using a half-resolution buffer.
Show Ambient Only¶
-
name:
showAmbientOnly
, type:
Bool
, default:
FALSE
¶ If checked, the SSAO term is rendered.
Mode (mode)¶
-
name:
mode
, type:
Enum
, default:
SSAO_HIGH_QUALITY
¶ Defines the quality mode.
Using high quality is recommended, but it is substantially slower.
Values:
Title | Name | Description |
---|---|---|
Low Quality | SSAO_LOW_QUALITY | Implements a simplified version of the original Nvidia algorithm, which is much faster but less precise/correct. |
High Quality | SSAO_HIGH_QUALITY | Implements “Horizon Based Ambient Occlusion” For more details, see here This software contains source code provided by NVIDIA Corporation. |
Mode (blurMode)¶
-
name:
blurMode
, type:
Enum
, default:
BILATERAL_BLUR
¶ Defines the blur mode.
Values:
Title | Name | Description |
---|---|---|
Bilateral Blur | BILATERAL_BLUR | Uses a bilateral blur filter that is edge preserving. |
Gaussian 9x9 | GAUSSIAN_9x9 | Uses a simple 9x9 Gauss filter to blur the ambient occlusion term. |