public class SoShadowGroup extends SoGroup
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.
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:
// The vertex shader: void OivSetupShadowVertex(); void main() { ..userCode.. //Needed for shadowing OivSetupShadowVertex(); } // The fragment shader: //If true we are in shadowmap generation pass uniform bool OivShadowPass; void OivGenerateShadowMap(); float OivComputeShadow(); void main() { if ( !OivShadowPass ) { ..compute fragment color here.. // Define the final color gl_FragColor.xyz = fragColor.xyz * OivComputeShadow(); gl_FragColor.w = fragColor.w; } else { // Output the shadowmap during the shadow map pass OivGenerateShadowMap(); } }
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.
Notes:
SoLightModel
node sets the lighting model to BASE_COLOR.
File format/default:
ShadowGroup {
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 |
See also:
Modifier and Type | Class and Description |
---|---|
static class |
SoShadowGroup.ShadowingMethods
Shadowing techniques.
|
static class |
SoShadowGroup.VisibilityFlags
visibilityRadius interpretation |
SoNode.RenderModes
Inventor.ConstructorCommand
Modifier and Type | Field and Description |
---|---|
SoSFFloat |
intensity
Specifies the intensity of the shadow.
|
SoSFBool |
isActive
Activates/deactivates the shadowing.
|
SoSFFloat |
lightBleedingReduction
In some cases, a halo may appear around shadows intersecting each other.
|
SoSFEnum<SoShadowGroup.ShadowingMethods> |
method
Specifies the shadowing technique to use.
|
SoSFFloat |
minVariance
Increasing this value will decrease possible self-shadowing artifacts but will make shadows fade away.
|
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.
|
SoSFInt32 |
smoothFactor
Set the smoothness of shadows.
|
SoSFEnum<SoShadowGroup.VisibilityFlags> |
visibilityFlag
Specifies how
visibilityRadius is interpreted. |
SoSFFloat |
visibilityRadius
Shadows are only computed within "visibility radius" distance from the camera position.
|
boundingBoxIgnoring
VERBOSE_LEVEL, ZeroHandle
Constructor and Description |
---|
SoShadowGroup()
Default constructor.
|
SoShadowGroup(int nChildren)
Constructor that takes approximate number of children.
|
Modifier and Type | Method and Description |
---|---|
static boolean |
isSupported()
Calls isSupported(SoShadowGroup.ShadowingMethods.valueOf( SoShadowGroup.ShadowingMethods.VARIANCE_SHADOW_MAP.getValue() )).
|
static boolean |
isSupported(SoShadowGroup.ShadowingMethods method)
Indicates if shadow casting is supported by your graphic board.
|
addChild, findChild, getChild, getNumChildren, insertChild, removeAllChildren, removeChild, removeChild, replaceChild, replaceChild
affectsState, callback, copy, copy, distribute, doAction, getAlternateRep, getBoundingBox, getByName, getMatrix, getPrimitiveCount, getRenderEngineMode, getRenderUnitID, GLRender, GLRenderBelowPath, GLRenderInPath, GLRenderOffPath, grabEventsCleanup, grabEventsSetup, handleEvent, isBoundingBoxIgnoring, isOverride, pick, rayPick, search, setOverride, touch, write
copyFieldValues, copyFieldValues, enableNotify, fieldsAreEqual, get, getAllFields, getEventIn, getEventOut, getField, getFieldName, hasDefaultValues, isNotifyEnabled, set, setToDefaults
dispose, getName, isDisposable, isSynchronizable, setName, setSynchronizable
getNativeResourceHandle
public final SoSFBool isActive
SoShadowGroup
behaves like an SoGroup
.public final SoSFFloat intensity
public final SoSFFloat precision
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.
public final SoSFFloat quality
public final SoSFBool shadowCachingEnabled
public final SoSFFloat visibilityRadius
visibilityRadius
if visibilityFlag
equals LONGEST_BBOX_EDGE_FACTOR
.
visibilityRadius
if visibilityFlag
equals ABSOLUTE_RADIUS
.
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.
public final SoSFEnum<SoShadowGroup.VisibilityFlags> visibilityFlag
visibilityRadius
is interpreted.
Use enum VisibilityFlag
. Default is LONGEST_BBOX_EDGE_FACTOR.public final SoSFInt32 smoothFactor
public final SoSFFloat minVariance
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].
public final SoSFFloat lightBleedingReduction
public final SoSFEnum<SoShadowGroup.ShadowingMethods> method
public SoShadowGroup()
public SoShadowGroup(int nChildren)
public static boolean isSupported()
public static boolean isSupported(SoShadowGroup.ShadowingMethods method)
SoGLExtension
for an example of using SoGLContext
to avoid them.Generated on July 31, 2019, Copyright © Thermo Fisher Scientific. All rights reserved. http://www.openinventor.com