- All Implemented Interfaces:
public class SoDepthOffset extends SoNodeProperty node that applies a depth offset. This node can be used to offset shapes that are co-planar, in order to resolve depth buffer artifacts, commonly called z-buffer "stitching".
The effect is similar to
SoPolygonOffsetbut this node uses a different algorithm (based on Lengyel's method from Game Programming Gems and improved by VSG) in which the projection matrix is modified to offset subsequent geometry. As a result it has advantages over
SoPolygonOffsetin some cases. Specifically,
SoDepthOffsetapplies its offset value to all types of geometry, not just polygons, and does not require any additional per-vertex calculations on the GPU.
offsetvalue is accumulated in the traversal state. For example: Note that if the accumulation of offset values during the traversal is greater than 1, the accumulated offset value is normalized so that, in this case, the offset values are not absolute but relative to each other.
SoDepthOffsethas two limitations. First, since it modifies the projection matrix during traversal, it may prevent building a render cache for part of the scene graph. Second, the offset does not take into account the depth slope of the geometry (as
SoPolygonOffsetdoes), so a larger offset may be required for geometry that is not perpendicular to the view vector (facing the camera).
The presence of a
SoDepthOffsetnode in the scene graph causes depth buffer values to be different, even if 'offset' is equal to 0.
The render caching issue is easily handled, by adjusting your scene graph structure, just as you would for any non-cacheable node, to ensure that the actual shape nodes are cached even if the parent group node cannot cache:
For example, using this scene graph structure:
instead of this one:
offset 0.001 on true
Constructors Constructor Description
Methods inherited from class com.openinventor.inventor.nodes.SoNode
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
Methods inherited from class com.openinventor.inventor.fields.SoFieldContainer
copyFieldValues, copyFieldValues, enableNotify, fieldsAreEqual, get, getAllFields, getEventIn, getEventOut, getField, getFieldName, hasDefaultValues, isNotifyEnabled, set, setToDefaults
Methods inherited from class com.openinventor.inventor.misc.SoBase
dispose, getName, isDisposable, isSynchronizable, setName, setSynchronizable
public final SoSFFloat offsetOffset to apply to the projection matrix.
Positive values move geometry toward the camera (the opposite of
SoPolygonOffset). Offset value must be in the range [-0.5 .. 0.5] (normalized depth coordinates). Default is 0.001
public final SoSFBool onEnables depth offset.
- Open Inventor 8.1