Shadow casting group node More...
#include <Inventor/nodes/SoShadowGroup.h>
Public Types | |
enum | VisibilityFlag { ABSOLUTE_RADIUS , LONGEST_BBOX_EDGE_FACTOR } |
visibilityRadius interpretation More... | |
enum | ShadowingMethod { VARIANCE_SHADOW_MAP } |
Shadowing techniques. More... | |
Public Member Functions | |
virtual SoType | getTypeId () const |
Returns the type identifier for this specific instance. | |
SoShadowGroup () | |
Default constructor. | |
SoShadowGroup (int nChildren) | |
Constructor that takes approximate number of children. | |
Public Member Functions inherited from SoGroup | |
SoGroup () | |
Creates an empty group node. | |
SoGroup (int nChildren) | |
Constructor that takes approximate number of children. | |
virtual void | addChild (SoNode *child) |
Adds a child as last one in group. | |
virtual void | insertChild (SoNode *child, int newChildIndex) |
Adds a child so that it becomes the one with the given index. | |
virtual SoNode * | getChild (int index) const |
Returns pointer the child node with the given index. | |
virtual int | findChild (const SoNode *child) const |
Finds index of given child within group. | |
virtual int | getNumChildren () const |
Returns number of children. | |
virtual void | removeChild (int index) |
Removes child with given index from group. | |
virtual void | removeChild (SoNode *child) |
Removes first instance of given child from group. | |
virtual void | removeAllChildren () |
Removes all children from group. | |
virtual void | replaceChild (int index, SoNode *newChild) |
Replaces child with given index with new child. | |
virtual void | replaceChild (SoNode *oldChild, SoNode *newChild) |
Replaces first instance of given child with new child. | |
Public Member Functions inherited from SoNode | |
virtual void | setOverride (const SbBool state) |
Turns the override flag on or off. | |
virtual SbBool | isOverride () const |
Returns the state of the override flag. | |
virtual SoNode * | copy (SbBool copyConnections=FALSE) const |
Creates and returns an exact copy of the node. | |
virtual SbBool | affectsState () const |
Returns TRUE if a node has an effect on the state during traversal. | |
virtual void | touch () |
Marks an instance as modified, simulating a change to it. | |
Public Member Functions inherited from SoFieldContainer | |
void | setToDefaults () |
Sets all fields in this object to their default values. | |
SbBool | hasDefaultValues () const |
Returns TRUE if all of the object's fields have their default values. | |
SbBool | fieldsAreEqual (const SoFieldContainer *fc) const |
Returns TRUE if this object's fields are exactly equal to fc's fields. | |
void | copyFieldValues (const SoFieldContainer *fc, SbBool copyConnections=FALSE) |
Copies the contents of fc's fields into this object's fields. | |
SoNONUNICODE SbBool | set (const char *fieldDataString) |
Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format. | |
SbBool | set (const SbString &fieldDataString) |
Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format. | |
void | get (SbString &fieldDataString) |
Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string. | |
virtual int | getFields (SoFieldList &list) const |
Appends references to all of this object's fields to resultList, and returns the number of fields appended. | |
virtual int | getAllFields (SoFieldList &list) const |
Returns a list of fields, including the eventIn's and eventOut's. | |
virtual SoField * | getField (const SbName &fieldName) const |
Returns a the field of this object whose name is fieldName. | |
virtual SoField * | getEventIn (const SbName &fieldName) const |
Returns a the eventIn with the given name. | |
virtual SoField * | getEventOut (const SbName &fieldName) const |
Returns the eventOut with the given name. | |
SbBool | getFieldName (const SoField *field, SbName &fieldName) const |
Returns the name of the given field in the fieldName argument. | |
SbBool | enableNotify (SbBool flag) |
Notification at this Field Container is enabled (if flag == TRUE) or disabled (if flag == FALSE). | |
SbBool | isNotifyEnabled () const |
Notification is the process of telling interested objects that this object has changed. | |
virtual void | setUserData (void *data) |
Sets application data. | |
void * | getUserData (void) const |
Gets user application data. | |
Public Member Functions inherited from SoBase | |
virtual SbName | getName () const |
Returns the name of an instance. | |
virtual void | setName (const SbName &name) |
Sets the name of an instance. | |
void | setSynchronizable (const bool b) |
Sets this to be a ScaleViz synchronizable object. | |
bool | isSynchronizable () const |
Gets the ScaleViz synchronizable state of this object. | |
Public Member Functions inherited from SoRefCounter | |
void | ref () const |
Adds a reference to an instance. | |
void | unref () const |
Removes a reference from an instance. | |
void | unrefNoDelete () const |
unrefNoDelete() should be called when it is desired to decrement the reference count, but not delete the instance if this brings the reference count to zero. | |
int | getRefCount () const |
Returns current reference count. | |
void | lock () const |
lock this instance. | |
void | unlock () const |
unlock this instance. | |
Public Member Functions inherited from SoTypedObject | |
SbBool | isOfType (const SoType &type) const |
Returns TRUE if this object is of the type specified in type or is derived from that type. | |
template<typename TypedObjectClass > | |
SbBool | isOfType () const |
Returns TRUE if this object is of the type of class TypedObjectClass or is derived from that class. | |
Static Public Member Functions | |
static SoType | getClassTypeId () |
Returns the type identifier for this class. | |
static SbBool | isSupported (SoShadowGroup::ShadowingMethod method=SoShadowGroup::VARIANCE_SHADOW_MAP) |
Indicates if shadow casting is supported by your graphic board. | |
Static Public Member Functions inherited from SoGroup | |
static SoType | getClassTypeId () |
Returns the type identifier for this class. | |
Static Public Member Functions inherited from SoNode | |
static SoType | getClassTypeId () |
Returns the type identifier for this class. | |
static SoNode * | getByName (const SbName &name) |
A node's name can be set using SoBase::setName(). | |
static int | getByName (const SbName &name, SoNodeList &list) |
A node's name can be set using SoBase::setName(). | |
Static Public Member Functions inherited from SoFieldContainer | |
static SoType | getClassTypeId () |
Returns the type of this class. | |
Static Public Member Functions inherited from SoBase | |
static SoType | getClassTypeId () |
Returns type identifier for this class. | |
Static Public Member Functions inherited from SoTypedObject | |
static SoType | getClassTypeId () |
Returns the type identifier for this class. | |
Public Attributes | |
SoSFBool | isActive |
Activates/deactivates the shadowing. | |
SoSFFloat | intensity |
Specifies the intensity of the shadow. | |
SoSFFloat | precision |
Specifies the precision of the shadow. | |
SoSFFloat | quality |
Specifies the quality of the shadow. | |
SoSFBool | shadowCachingEnabled |
Indicates if a cache should be used for computing the shadows. | |
SoSFFloat | visibilityRadius |
Shadows are only computed within "visibility radius" distance from the camera position. | |
SoSFEnum | visibilityFlag |
Specifies how visibilityRadius is interpreted. | |
SoSFInt32 | smoothFactor |
Set the smoothness of shadows. | |
SoSFFloat | minVariance |
Increasing this value will decrease possible self-shadowing artifacts but will make shadows fade away. | |
SoSFFloat | lightBleedingReduction |
In some cases, a halo may appear around shadows intersecting each other. | |
SoSFEnum | method |
Specifies the shadowing technique to use. | |
Public Attributes inherited from SoGroup | |
SoSFBool | boundingBoxIgnoring |
Whether to ignore this node during bounding box traversal. | |
This group node performs real-time shadow casting. Because shadows depends on a lot of OpenInventor elements, it is recommended to put children of this group under a SoSeparator in order to have a cache. Each shape within this group will be included in the shadow casting computation. A shape may cast a shadow on other shapes or on itself (self-shadowing), and/or may be shadowed by other shapes within the group. The current shadow style is used to determine if shapes cast a shadow and/or can be shadowed (see SoShadowStyle).
This class defines a single shadowing method. The method field allows for future shadowing methods to be added.
VARIANCE_SHADOW_MAP : This mode allows to display soft shadows. The smoothFactor field can be used to increase or decrease the softness. Aliasing won't be displayed, but on large scenes shadows will progressively fade away. Increasing quality will reduce this problem. Only the last on state directional light is used during rendering, other lights are ignored.
Shaders
Only the VARIANCE_SHADOW_MAP method is available with shaders (custom or internal). In order to use shadows with user defined GLSL shaders (SoShaderProgram or SoVolumeShader), the following functions must be used in the shader programs.
In the vertex shader:
In the fragment shader:
The following uniform is available in vertex and fragment shaders:
The following code can be used as a skeleton for a GLSL shader that works with shadows:
Transparency:
Transparent objects are treated as follows, depending on the transparency type:
Texture units:
In VARIANCE_SHADOW_MAP mode, this node reserves texture unit OIV_SHADOW_TEXTURE_UNIT0 for its rendering (see SoPreferences to set these). If this value is not set the application can specify which texture units OpenInventor should automatically use by setting environment variables (see SoPreferences). The texture units between OIV_FIRST_RESERVED_TEXTURE_UNIT and OIV_FIRST_RESERVED_TEXTURE_UNIT + SoShaderProgram::getNumReservedTextures() -1 inclusive are reserved for internal OpenInventor use. If OIV_FIRST_RESERVED_TEXTURE_UNIT is not set, its default value is SoFragmentShader::getMaxTextureImageUnit()-SoShaderProgram::getNumReservedTextures(). Note: The value returned by SoShaderProgram::getNumReservedTextures() may change between OpenInventor versions. The total number of available texture units depends on the graphics hardware.
Hardware requirements:
The Shadow and Depth Texture OpenGL extensions (standard in OpenGL 1.4) are used if they are available and generally improve performance.
In order to increase quality and performance of the shadows, OpenGL PBuffers are used. PBuffers are a limited resource on some systems. Set OIV_PBUFFER_ENABLE to 0 to disallow use of PBuffers.
A DirectX 10 graphics board is needed to support VARIANCE_SHADOW_MAP.
Use the isSupported() static method to determine if the current graphics board supports shadowing.
Limitations
Notes:
isActive | TRUE |
isShapesBefore | FALSE |
intensity | 0.5 |
precision | 0.5 |
quality | 0.5 |
shadowCachingEnabled | TRUE |
visibilityRadius | 1.0 |
visibilityFlag | LONGEST_BBOX_EDGE_FACTOR |
smoothFactor | 1 |
minVariance | 1e-5 |
method | VARIANCE_SHADOW_MAP |
lightBleedingReduction | 0.01 |
Definition at line 180 of file SoShadowGroup.h.
Shadowing techniques.
Enumerator | |
---|---|
VARIANCE_SHADOW_MAP | Shadows with soft edges. |
Definition at line 209 of file SoShadowGroup.h.
visibilityRadius interpretation
Enumerator | |
---|---|
ABSOLUTE_RADIUS | visibilityRadius is interpreted as an absolute value. |
LONGEST_BBOX_EDGE_FACTOR | The longest edge of the scene bounding box will be multiplied by the value of visibilityRadius. The resulting value will be the radius within which shadows are computed. |
Definition at line 189 of file SoShadowGroup.h.
SoShadowGroup::SoShadowGroup | ( | ) |
Default constructor.
SoShadowGroup::SoShadowGroup | ( | int | nChildren | ) |
Constructor that takes approximate number of children.
|
static |
Returns the type identifier for this class.
|
virtual |
Returns the type identifier for this specific instance.
Reimplemented from SoGroup.
|
static |
Indicates if shadow casting is supported by your graphic board.
When using a debug build of Open Inventor, some "no context available" warning messages may be generated. You can ignore them or see SoGLExtension for an example of using SoGLContext to avoid them.
SoSFFloat SoShadowGroup::intensity |
Specifies the intensity of the shadow.
0 = lowest intensity (the shadow is invisible), 1 = highest intensity (the shadow is solid black).
Definition at line 240 of file SoShadowGroup.h.
SoSFBool SoShadowGroup::isActive |
Activates/deactivates the shadowing.
If deactivated, this SoShadowGroup behaves like an SoGroup.
Definition at line 233 of file SoShadowGroup.h.
SoSFFloat SoShadowGroup::lightBleedingReduction |
In some cases, a halo may appear around shadows intersecting each other.
Increasing this value will decrease this effect. Default value is safe for most scenes. Default is 0.01 and range is [0-1].
NOTE: field available since Open Inventor 8.1
Definition at line 322 of file SoShadowGroup.h.
SoSFEnum SoShadowGroup::method |
Specifies the shadowing technique to use.
Use enum ShadowingMethod. Default is VARIANCE_SHADOW_MAP.
NOTE: field available since Open Inventor 8.1
Definition at line 330 of file SoShadowGroup.h.
SoSFFloat SoShadowGroup::minVariance |
Increasing this value will decrease possible self-shadowing artifacts but will make shadows fade away.
The default value is safe for most scenes. Increasing the quality field is also preferable before tweaking this value. A special case is for SoVolumeRender node which has a minimum of 0.001 or IVVR_SHADOW_MIN_VARIANCE if set. Default is 1e-5 and range is [0-1].
NOTE: field available since Open Inventor 8.1
Definition at line 312 of file SoShadowGroup.h.
SoSFFloat SoShadowGroup::precision |
Specifies the precision of the shadow.
0 = lowest precision, 1 = highest precision. With lower precisions, some parts of the scene may be unlit where they should be lit, or vice versa. Increasing the precision will reduce performance.
NOTE: If your graphics driver does not support the required OpenGL extensions, you may see low precision results even when this field is set to the highest precision.
Definition at line 253 of file SoShadowGroup.h.
SoSFFloat SoShadowGroup::quality |
Specifies the quality of the shadow.
The texture used for shadowmap rendering will be of size 2*quality*ViewportSize. Increasing the quality will reduce performance and increase memory consumption.
Definition at line 261 of file SoShadowGroup.h.
SoSFBool SoShadowGroup::shadowCachingEnabled |
Indicates if a cache should be used for computing the shadows.
Using a cache will improve rendering performance if the lights of your scene and your scene under this group node do not change.
Definition at line 268 of file SoShadowGroup.h.
SoSFInt32 SoShadowGroup::smoothFactor |
Set the smoothness of shadows.
Higher values give smoother shadows. Default is 1.
NOTE: field available since Open Inventor 8.1
Definition at line 300 of file SoShadowGroup.h.
SoSFEnum SoShadowGroup::visibilityFlag |
Specifies how visibilityRadius is interpreted.
Use enum VisibilityFlag. Default is LONGEST_BBOX_EDGE_FACTOR.
Definition at line 291 of file SoShadowGroup.h.
SoSFFloat SoShadowGroup::visibilityRadius |
Shadows are only computed within "visibility radius" distance from the camera position.
This radius equals:
When visibilityRadius = 1 and visibilityFlag = LONGEST_BBOX_EDGE_FACTOR (default values), shadowing is computed throughout the entire scene.
Note: With VARIANCE_SHADOW_MAP method, try to increase the quality field first.
Definition at line 285 of file SoShadowGroup.h.