PostProcessEffectsControl
- class HPS.PostProcessEffectsControl : public HPS.Control
The HPS.PostProcessEffectsControl class is a smart pointer that is tied to a database object. This object is effective only for the shader-based driver interfaces such as DirectX and OpenGL2. Ambient occlusion, bloom, silhouette edges, and depth of field are all enabled through this control. Default values for the various fields of HPS.PostProcessEffectsControl can be found here.
Public Functions
- override void Dispose ()
- override HPS.Type ObjectType ()
This function returns the type the object, as declared (if the object is derived, this does not give the true type of the derived object).
- Return
The declared type of the object in question, which may differ from the true, underlying type.
- PostProcessEffectsControl (HPS.PostProcessEffectsControl in_that)
Initializes a control tied to the same object as in_that.
- PostProcessEffectsControl (HPS.WindowKey in_seg)
Initializes a control tied to the window segment in_seg.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (bool in_state)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_state
Whether ambient occlusion should be used.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (bool in_state, float in_strength)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_state
Whether ambient occlusion should be used.
- Param in_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (bool in_state, float in_strength, HPS.PostProcessEffects.AmbientOcclusion.Quality in_quality)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_state
Whether ambient occlusion should be used.
- Param in_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Param in_quality
Indicates how much time should be spent improving the visual quality.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (bool in_state, float in_strength, HPS.PostProcessEffects.AmbientOcclusion.Quality in_quality, float in_radius)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_state
Whether ambient occlusion should be used.
- Param in_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Param in_quality
Indicates how much time should be spent improving the visual quality.
- Param in_radius
A multiplier for the screen-space search radius.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (bool in_state, float in_strength, HPS.PostProcessEffects.AmbientOcclusion.Quality in_quality, float in_radius, float in_sharpness)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_state
Whether ambient occlusion should be used.
- Param in_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Param in_quality
Indicates how much time should be spent improving the visual quality.
- Param in_radius
A multiplier for the screen-space search radius.
- Param in_sharpness
A value from 0.0f to 32.0f where lower values result in more blurred but softer edges and higher values will be blurred less with harder edges yet with more potential for banding. Higher values increase the search radius for occluding pixels, but may cause under-sampling artifacts.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (float in_strength)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas. The state is implicitly on.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (float in_strength, HPS.PostProcessEffects.AmbientOcclusion.Quality in_quality)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas. The state is implicitly on.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Param in_quality
Indicates how much time should be spent improving the visual quality.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (float in_strength, HPS.PostProcessEffects.AmbientOcclusion.Quality in_quality, float in_radius)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas. The state is implicitly on.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Param in_quality
Indicates how much time should be spent improving the visual quality.
- Param in_radius
A multiplier for the screen-space search radius.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetAmbientOcclusion (float in_strength, HPS.PostProcessEffects.AmbientOcclusion.Quality in_quality, float in_radius, float in_sharpness)
Ambient occlusion is a general term for shading that varies when nearby objects (occluders) would prevent some portion of ambient light from reaching a surface. This applies a filter that looks for small valleys in the depth buffer results, and slightly darkens these areas. The state is implicitly on.
Note
Ambient occlusion uses the depth buffer that is generated when we render opaque geometry to approximate ambient occlusion. Drawing of transparent geometry is always deferred until after all opaque geometry is drawn, and doesn’t write any depth information to the depth buffer. Thus, transparent geometry will effectively not exist for ambient occlusion calculations, and will therefore be unaffected by them. This also means that if all geometry in a scene is transparent, ambient occlusion is effectively disabled.
- Param in_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Param in_quality
Indicates how much time should be spent improving the visual quality.
- Param in_radius
A multiplier for the screen-space search radius.
- Param in_sharpness
A value from 0.0f to 32.0f where lower values result in more blurred but softer edges and higher values will be blurred less with harder edges yet with more potential for banding. Higher values increase the search radius for occluding pixels, but may cause under-sampling artifacts.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetBloom (bool in_state)
Bloom causes bright objects to bleed into darker ones, simulating the imperfect focus inevitable with the human eye or any other type of lens.
- Param in_state
Whether bloom should be used.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetBloom (bool in_state, float in_strength)
Bloom causes bright objects to bleed into darker ones, simulating the imperfect focus inevitable with the human eye or any other type of lens.
- Param in_state
Whether bloom should be used.
- Param in_strength
A multiplier on the default contribution of bloom. Higher values mean that bloom will make a stronger contribution. Valid range is [0,10].
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetBloom (bool in_state, float in_strength, uint in_blur)
Bloom causes bright objects to bleed into darker ones, simulating the imperfect focus inevitable with the human eye or any other type of lens.
- Param in_state
Whether bloom should be used.
- Param in_strength
A multiplier on the default contribution of bloom. Higher values mean that bloom will make a stronger contribution. Valid range is [0,10].
- Param in_blur
The number of blur passes to perform on the output. Higher values mean that bloom will affect a wider area and look smoother. Valid range is [1,8].
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetBloom (bool in_state, float in_strength, uint in_blur, HPS.PostProcessEffects.Bloom.Shape in_shape)
Bloom causes bright objects to bleed into darker ones, simulating the imperfect focus inevitable with the human eye or any other type of lens.
- Param in_state
Whether bloom should be used.
- Param in_strength
A multiplier on the default contribution of bloom. Higher values mean that bloom will make a stronger contribution. Valid range is [0,10].
- Param in_blur
The number of blur passes to perform on the output. Higher values mean that bloom will affect a wider area and look smoother. Valid range is [1,8].
- Param in_shape
The shape of the bloom effect.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetBloom (float in_strength, uint in_blur, HPS.PostProcessEffects.Bloom.Shape in_shape)
Bloom causes bright objects to bleed into darker ones, simulating the imperfect focus inevitable with the human eye or any other type of lens. The state is implicitly on.
- Param in_strength
A multiplier on the default contribution of bloom. Higher values mean that bloom will make a stronger contribution. Valid range is [0,10].
- Param in_blur
The number of blur passes to perform on the output. Higher values mean that bloom will affect a wider area and look smoother. Valid range is [1,8].
- Param in_shape
The shape of the bloom effect.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetDepthOfField (bool in_state)
Depth of Field is the distance between the nearest and farthest objects in a scene that appear sharp.
- Param in_state
Whether depth of field should be used.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetDepthOfField (bool in_state, float in_strength)
Depth of Field is the distance between the nearest and farthest objects in a scene that appear sharp.
- Param in_state
Whether depth of field should be used.
- Param in_strength
A multiplier on the default blur radius. Higher values mean more blurring.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetDepthOfField (bool in_state, float in_strength, float in_near_distance)
Depth of Field is the distance between the nearest and farthest objects in a scene that appear sharp.
- Param in_state
Whether depth of field should be used.
- Param in_strength
A multiplier on the default blur radius. Higher values mean more blurring.
- Param in_near_distance
The camera distance in front of which geometry will begin to appear out of focus.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetDepthOfField (bool in_state, float in_strength, float in_near_distance, float in_far_distance)
Depth of Field is the distance between the nearest and farthest objects in a scene that appear sharp.
- Param in_state
Whether depth of field should be used.
- Param in_strength
A multiplier on the default blur radius. Higher values mean more blurring.
- Param in_near_distance
The camera distance in front of which geometry will begin to appear out of focus.
- Param in_far_distance
The camera distance beyond which geometry will appear out of focus.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetDepthOfField (float in_strength, float in_near_distance, float in_far_distance)
Depth of Field is the distance between the nearest and farthest objects in a scene that appear sharp. The state is implicitly on.
- Param in_strength
A multiplier on the default blur radius. Higher values mean more blurring.
- Param in_near_distance
The camera distance in front of which geometry will begin to appear out of focus.
- Param in_far_distance
The camera distance beyond which geometry will appear out of focus.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetEyeDomeLighting (bool in_state)
Controls the shader-based eye-dome lighting effect.
- Param in_state
Whether eye-dome lighting should be used.
- Return
true if the setting is valid, false otherwise.
- HPS.PostProcessEffectsControl SetEyeDomeLighting (bool in_state, float in_exponent)
Controls the shader-based eye-dome lighting effect.
- Param in_state
Whether eye-dome lighting should be used.
- Param in_exponent
An exponent used to attenuate the per-pixel occlusion computed by the eye-dome lighting algorithm.
- Return
true if the setting is valid, false otherwise.
- HPS.PostProcessEffectsControl SetEyeDomeLighting (bool in_state, float in_exponent, float in_tolerance)
Controls the shader-based eye-dome lighting effect.
- Param in_state
Whether eye-dome lighting should be used.
- Param in_exponent
An exponent used to attenuate the per-pixel occlusion computed by the eye-dome lighting algorithm.
- Param in_tolerance
A multiplier on the threshold that the driver uses when comparing adjacent pixel depth values to detect occlusion. This allows the user to control the amount of occlusion added by neighboring pixels based on their relative depth difference.
- Return
true if the setting is valid, false otherwise.
- HPS.PostProcessEffectsControl SetEyeDomeLighting (bool in_state, float in_exponent, float in_tolerance, float in_strength)
Controls the shader-based eye-dome lighting effect.
- Param in_state
Whether eye-dome lighting should be used.
- Param in_exponent
An exponent used to attenuate the per-pixel occlusion computed by the eye-dome lighting algorithm.
- Param in_tolerance
A multiplier on the threshold that the driver uses when comparing adjacent pixel depth values to detect occlusion. This allows the user to control the amount of occlusion added by neighboring pixels based on their relative depth difference.
- Param in_strength
A multiplier on the calculated per-pixel occlusion value.
- Return
true if the setting is valid, false otherwise.
- HPS.PostProcessEffectsControl SetEyeDomeLighting (float in_exponent, float in_tolerance, float in_strength)
Controls the shader-based eye-dome lighting effect. The state is implicitly on.
- Param in_exponent
An exponent used to attenuate the per-pixel occlusion computed by the eye-dome lighting algorithm.
- Param in_tolerance
A multiplier on the threshold that the driver uses when comparing adjacent pixel depth values to detect occlusion. This allows the user to control the amount of occlusion added by neighboring pixels based on their relative depth difference.
- Param in_strength
A multiplier on the calculated per-pixel occlusion value.
- Return
true if the setting is valid, false otherwise.
- HPS.PostProcessEffectsControl SetSilhouetteEdges (bool in_state)
Controls the shader-based fast drawing of silhouette edges.
- Param in_state
Whether silhouette edges should be used.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetSilhouetteEdges (bool in_state, float in_tolerance)
Controls the shader-based fast drawing of silhouette edges.
- Param in_state
Whether silhouette edges should be used.
- Param in_tolerance
A multiplier on the threshold that the driver uses when comparing adjacent pixel depth values to detect silhouettes. This allows the user to control the trade-off between silhouettes appearing where they shouldn’t, vs disappearing in places they should be.
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetSilhouetteEdges (bool in_state, float in_tolerance, bool in_heavy_exterior)
Controls the shader-based fast drawing of silhouette edges.
- Param in_state
Whether silhouette edges should be used.
- Param in_tolerance
A multiplier on the threshold that the driver uses when comparing adjacent pixel depth values to detect silhouettes. This allows the user to control the trade-off between silhouettes appearing where they shouldn’t, vs disappearing in places they should be.
- Param in_heavy_exterior
This option, when enabled, causes an extra thick border to be drawn at the boundary between geometry and the window background (as opposed to geometry on top of other geometry).
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetSilhouetteEdges (float in_tolerance, bool in_heavy_exterior)
Controls the shader-based fast drawing of silhouette edges. The state is implicitly on.
- Param in_tolerance
A multiplier on the threshold that the driver uses when comparing adjacent pixel depth values to detect silhouettes. This allows the user to control the trade-off between silhouettes appearing where they shouldn’t, vs disappearing in places they should be.
- Param in_heavy_exterior
This option, when enabled, causes an extra thick border to be drawn at the boundary between geometry and the window background (as opposed to geometry on top of other geometry).
- Return
A reference to this object.
- HPS.PostProcessEffectsControl SetWorldScale (float in_scale)
Sets a world scale value used by post process effects such as ambient occlusion. If not set, scale is computed based on scene bounding.
- Param in_scale
Scale value used by post process effect.
- Return
A reference to this object.
- bool ShowAmbientOcclusion (out bool out_state, out float out_strength, out HPS.PostProcessEffects.AmbientOcclusion.Quality out_quality, out float out_radius, out float out_sharpness)
Shows the ambient occlusion setting.
- Param out_state
Whether ambient occlusion should be used.
- Param out_strength
A multiplier on the default contribution of ambient occlusion in the regular lighting calculations. Higher values mean that ambient occlusion will make a stronger contribution.
- Param out_quality
Indicates how much time should be spent improving the visual quality.
- Param out_radius
A multiplier for the screen-space search radius.
- Param out_sharpness
A value indicating the sharpness of the ambient occlusion edges. Higher values increase the search radius for occluding pixels, but may cause under-sampling artifacts.
- Return
true if the setting is valid, false otherwise.
- bool ShowBloom (out bool out_state, out float out_strength, out uint out_blur, out HPS.PostProcessEffects.Bloom.Shape out_shape)
Shows the bloom setting.
- Param out_state
Whether bloom should be used.
- Param out_strength
A multiplier on the default contribution of bloom. Higher values mean that bloom will make a stronger contribution.
- Param out_blur
The number of blur passes to perform on the output. Higher values mean that bloom will affect a wider area and look smoother.
- Param out_shape
The shape of the bloom effect.
- Return
true if the setting is valid, false otherwise.
- bool ShowDepthOfField (out bool out_state, out float out_strength, out float out_near_distance, out float out_far_distance)
Shows the depth of field setting.
- Param out_state
Whether depth of field should be used.
- Param out_strength
A multiplier on the default blur radius. Higher values mean more blurring.
- Param out_near_distance
The camera distance in front of which geometry will begin to appear out of focus.
- Param out_far_distance
The camera distance beyond which geometry will appear out of focus.
- Return
true if the setting is valid, false otherwise.
- bool ShowEyeDomeLighting (out bool out_state, out float out_exponent, out float out_tolerance, out float out_strength)
Shows the eye-dome lighting setting.
- Param out_state
Whether eye-dome lighting should be used.
- Param out_exponent
An exponent used to attenuate the per-pixel occlusion computed by the eye-dome lighting algorithm.
- Param out_tolerance
A multiplier on the threshold that the driver uses when comparing adjacent pixel depth values to detect occlusion. This allows the user to control the amount of occlusion added by neighboring pixels based on their relative depth difference.
- Param out_strength
A multiplier on the calculated per-pixel occlusion value.
- Return
true if the setting is valid, false otherwise.
- bool ShowSilhouetteEdges (out bool out_state, out float out_tolerance, out bool out_heavy_exterior)
Shows the silhouette edge setting.
- Param out_state
Whether silhouette edges should be used.
- Param out_tolerance
A multiplier on the threshold that the driver uses when comparing adjacent pixel depth values to detect silhouettes. This allows the user to control the trade-off between silhouettes appearing where they shouldn’t, vs disappearing in places they should be.
- Param out_heavy_exterior
This option, when enabled, causes an extra thick border to be drawn at the boundary between geometry and the window background (as opposed to geometry on top of other geometry).
- Return
true if the setting is valid, false otherwise.
- bool ShowWorldScale (out float out_scale)
Shows the world scale setting.
- Param out_scale
Scale value used by post process effects.
- Return
true if the setting is valid, false otherwise.
- HPS.PostProcessEffectsControl UnsetAmbientOcclusion ()
Removes any ambient occlusion setting. If the control is attached to a WindowKey this function restores the default value of this setting as specified by PostProcessEffectsKit.GetDefault().
- Return
A reference to this object.
- HPS.PostProcessEffectsControl UnsetBloom ()
Removes a bloom setting. If the control is attached to a WindowKey this function restores the default value of this setting as specified by PostProcessEffectsKit.GetDefault().
- Return
A reference to this object.
- HPS.PostProcessEffectsControl UnsetDepthOfField ()
Removes a depth of field setting. If the control is attached to a WindowKey this function restores the default value of this setting as specified by PostProcessEffectsKit.GetDefault().
- Return
A reference to this object.
- HPS.PostProcessEffectsControl UnsetEverything ()
Removes all settings from this object. If the control is attached to a WindowKey this function restores the default settings of this control as specified by PostProcessEffectsKit.GetDefault().
- Return
A reference to this object.
- HPS.PostProcessEffectsControl UnsetEyeDomeLighting ()
Removes an eye-dome lighting setting. If the control is attached to a WindowKey this function restores the default value of this setting as specified by PostProcessEffectsKit.GetDefault().
- Return
A reference to this object.
- HPS.PostProcessEffectsControl UnsetSilhouetteEdges ()
Removes a silhouette edge setting. If the control is attached to a WindowKey this function restores the default value of this setting as specified by PostProcessEffectsKit.GetDefault().
- Return
A reference to this object.
- HPS.PostProcessEffectsControl UnsetWorldScale ()
Removes any world scale setting. If the control is attached to a WindowKey this function restores the default value of this setting as specified by PostProcessEffectsKit.GetDefault().
- Return
A reference to this object.