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SoBufferedShape Class

Node to render geometry stored in OIV.Inventor.Devices.SoBufferObject objects.

Inheritance Hierarchy

Namespace: OIV.Inventor.Nodes
Assembly: OIV.Inventor (in OIV.Inventor.dll) Version: 10.12.3.0 (10.12.3.0)
Syntax
public class SoBufferedShape : SoShape

The SoBufferedShape type exposes the following members.

Constructors
  NameDescription
Public methodSoBufferedShape

Default constructor.

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Methods
  NameDescription
Public methodAffectsState

Overrides default method on OIV.Inventor.Nodes.SoNode.

(Inherited from SoShape.)
Public methodBeginShape(SoAction, SoShapeTriangleShapes)
Calls BeginShape(action, shapeType, (OIV.Inventor.Details.SoFaceDetail ^)nullptr).
(Inherited from SoShape.)
Public methodBeginShape(SoAction, SoShapeTriangleShapes, SoFaceDetail)

These methods can be used by subclasses to generate triangles more easily when those triangles are part of a larger structure, such as a triangle strip, triangle fan, or triangulated polygon, according to the TriangleShape enumerated type.

(Inherited from SoShape.)
Public methodCallback

Implements primitive generation for all shapes.

(Inherited from SoShape.)
Public methodComputeBBox(SoAction, SbBox3f, SbVec3f)

Computes the AABB bounding box if it must be updated.

(Overrides SoShapeComputeBBox(SoAction, SbBox3f, SbVec3f).)
Public methodComputeBBox(SoAction, SbXfBox3d, SbVec3d)

Computes the OOB bounding box if it must be updated.

(Overrides SoShapeComputeBBox(SoAction, SbXfBox3d, SbVec3d).)
Public methodCopy
Calls Copy(false).
(Inherited from SoNode.)
Public methodCopy(Boolean)

Creates and returns an exact copy of the node.

(Inherited from SoNode.)
Public methodCopyFieldValues(SoFieldContainer)
Calls CopyFieldValues(fc, false).
(Inherited from SoFieldContainer.)
Public methodCopyFieldValues(SoFieldContainer, Boolean)

Copies the contents of fc's fields into this object's fields.

(Inherited from SoFieldContainer.)
Public methodDispose
Releases all resources used by SoDisposable.
(Inherited from SoDisposable.)
Public methodDistribute
(Inherited from SoNode.)
Public methodDoAction
(Inherited from SoNode.)
Public methodEnableNotify

Notification at this Field Container is enabled (if flag == true) or disabled (if flag == false).

(Inherited from SoFieldContainer.)
Public methodEndShape

end shape previously started with OIV.Inventor.Nodes.SoShape.BeginShape(OIV.Inventor.Actions.SoAction, OIV.Inventor.Nodes.SoShape.TriangleShapes, OIV.Inventor.Details.SoFaceDetail).

(Inherited from SoShape.)
Public methodEquals
Determines whether the specified Object is equal to the current Object.
(Inherited from Object.)
Public methodFieldsAreEqual

Returns true if this object's fields are exactly equal to fc's fields.

(Inherited from SoFieldContainer.)
Public methodGet

Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string.

(Inherited from SoFieldContainer.)
Public methodGetAllFields

Returns a list of fields, including the eventIn's and eventOut's.

(Inherited from SoFieldContainer.)
Public methodGetAlternateRep

This method is called by actions to allow the node to provide an "alternate representation" when appropriate (typically depending on the action type).

(Inherited from SoNode.)
Public methodGetBoundingBox

Manages getBoundingBoxAction action.

(Overrides SoShapeGetBoundingBox(SoGetBoundingBoxAction).)
Public methodGetEventIn

Returns a the eventIn with the given name.

(Inherited from SoFieldContainer.)
Public methodGetEventOut

Returns the eventOut with the given name.

(Inherited from SoFieldContainer.)
Public methodGetField

Returns a the field of this object whose name is fieldName.

(Inherited from SoFieldContainer.)
Public methodGetFieldName

Returns the name of the given field in the fieldName argument.

(Inherited from SoFieldContainer.)
Public methodGetFields

Appends references to all of this object's fields to resultList, and returns the number of fields appended.

(Inherited from SoFieldContainer.)
Public methodGetHashCode
Overrides GetHashCode().
(Inherited from SoNetBase.)
Public methodGetMatrix
(Inherited from SoNode.)
Public methodGetName

Returns the name of an instance.

(Inherited from SoBase.)
Public methodGetPrimitiveCount

Manages getPrimitiveCount action.

(Overrides SoShapeGetPrimitiveCount(SoGetPrimitiveCountAction).)
Public methodGetRenderEngineMode

Returns the supported Render engine mode.

(Inherited from SoNode.)
Public methodGetRenderUnitID
(Inherited from SoNode.)
Public methodGetShapeType

Gets the current shape Full Scene Antialiasing type.

(Inherited from SoShape.)
Public methodGetStringName (Inherited from SoBase.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodGLRender

Manages GLRender action.

(Overrides SoShapeGLRender(SoGLRenderAction).)
Public methodGLRenderBelowPath
(Inherited from SoNode.)
Public methodGLRenderInPath
(Inherited from SoNode.)
Public methodGLRenderOffPath
(Inherited from SoNode.)
Public methodGrabEventsCleanup
(Inherited from SoNode.)
Public methodGrabEventsSetup
(Inherited from SoNode.)
Public methodHandleEvent
(Inherited from SoNode.)
Public methodHasDefaultValues

Returns true if all of the object's fields have their default values.

(Inherited from SoFieldContainer.)
Public methodIsBoundingBoxIgnoring

Used by BoundingBoxAction to know if bounding box computation should be ignored or not.

(Inherited from SoShape.)
Public methodIsNotifyEnabled

Notification is the process of telling interested objects that this object has changed.

(Inherited from SoFieldContainer.)
Public methodIsOverride

Returns the state of the override flag.

(Inherited from SoNode.)
Public methodIsSynchronizable

Gets the ScaleViz synchronizable state of this object.

(Inherited from SoBase.)
Public methodPick
(Inherited from SoNode.)
Public methodRayPick

Manages ray pick action.

(Overrides SoShapeRayPick(SoRayPickAction).)
Public methodSearch
(Inherited from SoNode.)
Public methodSet

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.

(Inherited from SoFieldContainer.)
Public methodSetName (Inherited from SoBase.)
Public methodSetOverride

Turns the override flag on or off.

(Inherited from SoNode.)
Public methodSetShapeType

set the antialiasing type for this shape.

(Inherited from SoShape.)
Public methodSetSynchronizable

Sets this to be a ScaleViz synchronizable object.

(Inherited from SoBase.)
Public methodSetToDefaults

Sets all fields in this object to their default values.

(Inherited from SoFieldContainer.)
Public methodShapeVertex

add a primitive vertex to the shape prevously started with OIV.Inventor.Nodes.SoShape.BeginShape(OIV.Inventor.Actions.SoAction, OIV.Inventor.Nodes.SoShape.TriangleShapes, OIV.Inventor.Details.SoFaceDetail).

(Inherited from SoShape.)
Public methodToString
Converts this SoBase structure to a human readable string.
(Inherited from SoBase.)
Public methodTouch

Marks an instance as modified, simulating a change to it.

(Inherited from SoNode.)
Public methodWrite
(Inherited from SoNode.)
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Properties
  NameDescription
Public propertyboundingBoxIgnoring

Whether to ignore this node during bounding box traversal.

(Inherited from SoShape.)
Public propertycolorBuffer

Buffer object that contains the (optional) color values.

Public propertycolorComponentsCount

Number of components in each color value.

Public propertycolorComponentsType

OIV.Inventor.SbDataType.DataTypes type for the color values.

Public propertycolorOffset

Offset in bytes to the first color value in the buffer.

Public propertycolorStride

Stride in bytes between the first component of two consecutive colors.

Public propertyindexBuffer

Buffer object that contains the (optional) indices.

Public propertyindexOffset

Offset in bytes to the first index in the buffer.

Public propertyindexType

OIV.Inventor.SbDataType.DataTypes type for the indices.

Public propertyIsDisposable
ISafeDisposable interface implementation.
(Inherited from SoDisposable.)
Public propertynormalBuffer

Buffer object that contains the (optional) normal vectors.

Public propertynormalComponentsType

OIV.Inventor.SbDataType.DataTypes type for the normal vectors.

Public propertynormalOffset

Offset in bytes to the first normal vector in the buffer.

Public propertynormalStride

Stride in bytes between the first component of two consecutive normals.

Public propertynumVertices

Total number of vertices/indices or number of vertices/indices to be used per primitive.

Public propertyprimitiveRestartEnabled

Enable/disable the primitive restart feature.

Public propertyprimitiveRestartValue

Index value for the primitive restart feature.

Public propertyshapeType

Shape type to render.

Public propertyshapeUsage

Defines the usage of the shape.

Public propertytexCoordsBuffer

Buffer objects that contains the (optional) texture coordinates.

Public propertytexCoordsComponentsCount

Number of components in each texture coordinate.

Public propertytexCoordsComponentsType

OIV.Inventor.SbDataType.DataTypes type for the texture coordinates.

Public propertytexCoordsOffset

Offset in bytes to the first texture coordinate in the buffer.

Public propertytexCoordsStride

Stride in bytes between the first component of two consecutive texture coordinates.

Public propertyuseNormalsGenerator

Indicates if the node should use the internal normal vector generator if no normals are defined.

Public propertyUserData
Gets or sets the user data to be contained by the field container.
(Inherited from SoFieldContainer.)
Public propertyvertexBuffer

Buffer object that contains the vertex data.

Public propertyvertexComponentsCount

Number of components in each vertex.

Public propertyvertexComponentsType
Public propertyvertexOffset

Offset in bytes to the first vertex within the buffer.

Public propertyvertexStride

Stride in bytes between the first component of two consecutive vertices.

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Remarks

OIV.Inventor.Nodes.SoBufferedShape is useful to manage the rendering of large geometry, provide application control over where the data is stored (CPU or GPU) and to integrate rendering with the Open Inventor computing framework (through the OIV.Inventor.Devices.SoBufferObject classes).

OIV.Inventor.Nodes.SoBufferedShape provides fields for:

  • Vertices

  • Indices (optional)

  • Colors (optional)

  • Normals (optional)

  • Texture coordinates (optional)

In this sense it is similar to the OIV.Inventor.Nodes.SoVertexProperty node, but OIV.Inventor.Nodes.SoVertexProperty is just a property node. OIV.Inventor.Nodes.SoBufferedShape also does the rendering of the shape. Properties that are not specified are taken from the traversal state (e.g. colors) or computed (e.g. normals).

OIV.Inventor.Nodes.SoBufferedShape can render many types of geometric primitives including points, lines, quads and triangles. (A single type must be specified per instance of OIV.Inventor.Nodes.SoBufferedShape.) You specify the type of primitive in the SoSFEnum field OIV.Inventor.Nodes.SoBufferedShape.shapeType.

OIV.Inventor.Nodes.SoBufferedShape can render multiple primitives of the same type. You can specify the number of vertices (or indices if provided) to use for each primitive in the OIV.Inventor.Fields.SoMFInt32 field OIV.Inventor.Nodes.SoBufferedShape.numVertices (similar to OIV.Inventor.Nodes.SoFaceSet).

You can also use the primitive restart feature to define multiple indexed strip shapes, for example TRIANGLE_STRIP or LINE_STRIP. The end of each primitive is marked by a special index value in the index buffer and this value can be specified in the OIV.Inventor.Nodes.SoBufferedShape.primitiveRestartValue field. The behavior is similar to the "-1" value that can be used in Open Inventor indexed shape nodes like OIV.Inventor.Nodes.SoIndexedFaceSet, but is implemented on the GPU. NOTE:

The geometry and its attributes must be stored in buffer objects (see OIV.Inventor.Devices.SoBufferObject). The buffer objects can be SoGpuBufferObjects stored directly on the graphics board or SoCpuBufferObjects stored in system memory. This allows the application to control what data is stored where.

In the general case, when the underlying buffer object is modified using the OIV.Inventor.Devices.SoBufferObject API (setSize, map, memcpy, memset), the containing OIV.Inventor.Fields.SoSFBufferObject field needs to be notified using OIV.Inventor.Nodes.SoNode.Touch() in order for Open Inventor to take this modification into account. If OIV.Inventor.Nodes.SoNode.Touch() is not called, there is no guarantee that the modifications will be visible on the next rendering.

If the application needs to frequently modify the values of an OIV.Inventor.Devices.SoBufferObject, calling OIV.Inventor.Nodes.SoNode.Touch() on the field can result in an undesirable decrease in performance. Instead, it is recommended to use an instance of OIV.Inventor.Devices.SoGpuBufferObject and set the OIV.Inventor.Nodes.SoBufferedShape.shapeUsage field to DYNAMIC. These settings guarantee that this buffer data will be used directly for rendering, and eliminate the need to call OIV.Inventor.Nodes.SoNode.Touch() on the field. It also guarantees that modifications to the buffer done by shaders will be properly taken into account.

If lighting is enabled (there is no OIV.Inventor.Nodes.SoLightModel node or the model field of the OIV.Inventor.Nodes.SoLightModel is set to PHONG) and the OIV.Inventor.Nodes.SoBufferedShape.normalBuffer field is not set, then Open Inventor will automatically compute normal vectors, but only in some cases (see Limitations section). Normal generation is affected by the creaseAngle field of the OIV.Inventor.Nodes.SoShapeHints node, but only if the vertices are NOT indexed (indexBuffer field is not set). If the vertices are indexed the creaseAngle is forced to PI, creating a smooth surface rendering. If the application needs to render sharp edges on a shape, either compute normal vectors and set the normalBuffer field or do not use the indexBuffer field. It is possible to disable normal generation (if for example the normals are generated by a geometry shader) by setting the OIV.Inventor.Nodes.SoBufferedShape.useNormalsGenerator field to false. If no normal vectors are specified or generated, and lighting is enabled, the primitive may not be rendered correctly.

OIV.Inventor.Nodes.SoBufferedShape provides fields to describe the content of each buffer, e.g. the data type and number of components in each buffer, as well as how to access the buffers, e.g. the offset into the buffer and "stride" separating data values in the buffer. The default values for offset and stride assume that the vertices, normals, etc are each in a separate buffer. However setting appropriate offset and stride allows, for example, vertices and normals to be interleaved in a single buffer. In this case the same buffer would be set into both the vertexBuffer and normalBuffer fields.

To disable computing the bounding box, which can take a long time with very large geometry, use the OIV.Inventor.Nodes.SoBBox node to specify a pre-computed bounding box.

Limitations

  • Transparency: If there is no color buffer, making the entire shape transparent using an OIV.Inventor.Nodes.SoMaterial node works as usual. However if there is a color buffer with RGBA values, note that Open Inventor does not currently check the color buffer for transparency (alpha values < 1). So in this case the OIV.Inventor.Nodes.SoBufferedShape will not be considered transparent geometry (even if there are alpha values < 1) and may not be rendered correctly. You can force Open Inventor to handle the shape as transparent geometry by putting an OIV.Inventor.Nodes.SoMaterial node with non-zero transparency before it in the scene graph.

  • Normal generation: If lighting is enabled and the normalBuffer field is not set, then Open Inventor will automatically compute normal vectors, but only in some cases. Automatic generation of normal vectors is ONLY enabled when:

  • OIV.Inventor.Actions.SoGetPrimitiveCountAction: When using the primitive restart feature, the triangle/line count returned by the OIV.Inventor.Actions.SoGetPrimitiveCountAction will not be accurate.

  • Concave polygons: Unlike (for example) OIV.Inventor.Nodes.SoFaceSet, OIV.Inventor.Nodes.SoBufferedShape does NOT automatically tesselate concave or complex polygons. Such primitives may not be rendered correctly.

  • OIV.Inventor.Actions.SoWriteAction: OIV.Inventor.Nodes.SoBufferedShape can be saved to and restored from a .iv file just like any other Open Inventor node. However, during the read operation any GPU buffer objects (OIV.Inventor.Devices.SoGpuBufferObject) in the file will be created as CPU buffers (OIV.Inventor.Devices.SoCpuBufferObject).

  • Material binding (etc): OIV.Inventor.Nodes.SoBufferedShape effectively only supports per-vertex and per-vertex-indexed binding of materials, normals and texture coordinates using the values found in its own buffers.

Example using CPU buffer:

float[] vertices = new float[9 * 3] {
       1.0f, 0.5f,0.0f, 0.0f, 1.0f,0.0f, -1.0f,0.5f,0.0f,
      -1.0f,-1.0f,0.0f, 1.0f,-1.0f,0.0f,  1.0f,0.0f,0.0f, -1.0f,0.0f,0.0f,
      -1.0f,-1.5f,0.0f, 1.0f,-1.5f,0.0f
};
Int32[] numVerts = new Int32[3] { 3, 4, 2 };

SbNativeArray<float> vertArray = new SbNativeArray<float>(vertices);
SoCpuBufferObject   vertBuffer = new SoCpuBufferObject((SbNativeArray<byte>)vertArray);

SoBufferedShape shape = new SoBufferedShape();
shape.shapeType.SetValue( "LINE_STRIP" );
shape.numVertices.SetValues( 0, numVerts );
shape.vertexBuffer.Value = vertBuffer;

Example using GPU buffer:

float[] vertices = new float[9 * 3] {
   1.0f, 0.5f,0.0f, 0.0f, 1.0f,0.0f, -1.0f,0.5f,0.0f,
   -1.0f,-1.0f,0.0f, 1.0f,-1.0f,0.0f,  1.0f,0.0f,0.0f, -1.0f,0.0f,0.0f,
   -1.0f,-1.5f,0.0f, 1.0f,-1.5f,0.0f
};
Int32[] numVerts = new Int32[3] { 3, 4, 2 };


SbNativeArray<float> vertArray = new SbNativeArray<float>(vertices);
SoCpuBufferObject vertBuf = new SoCpuBufferObject( (SbNativeArray<byte>)vertArray );

SoGLContext glContext = new SoGLContext(true);
glContext.Bind();
   SoGpuBufferObject gpuBuffer = new SoGpuBufferObject( SoGpuBufferObject.BufferAccessFrequencies.STATIC, SoGpuBufferObject.BufferAccessNatures.SHARED );
   gpuBuffer.SetSize( cpuBuffer.GetSize() );  // Set the buffer size (allocate memory)
   gpuBuffer.Memcpy ( cpuBuffer );            // Copy data into the buffer
glContext.Unbind();

SoBufferedShape shape = new SoBufferedShape();
shape.shapeType.SetValue("LINE_STRIP");
shape.numVertices.SetValues(0, numVerts);
shape.vertexBuffer.Value = gpuBuffer;
root.AddChild(shape);

LIMITATIONS: OIV.Inventor.Nodes.SoBufferedShape needs a graphic card supporting vertex buffer objects, if not available shape won't be rendered.

FILE FORMAT/DEFAULT

BufferedShape {
useNormalsGenerator true
shapeType TRIANGLES
numVertices 0
vertexBuffer NULL
vertexComponentsCount 3
vertexComponentsType OIV.Inventor.SbDataType.DataTypes.FLOAT
vertexStride 0
vertexOffset 0
normalBuffer NULL
normalComponentsType OIV.Inventor.SbDataType.DataTypes.FLOAT
normalStride 3 * sizeof(float)
normalOffset 0
indexBuffer NULL
indexType OIV.Inventor.SbDataType.DataTypes.UNSIGNED_INT32
indexOffset 0
colorBuffer NULL
colorComponentsType OIV.Inventor.SbDataType.DataTypes.FLOAT
colorStride 0
colorOffset 0
colorComponentsCount 3
texCoordsBuffer NULL
texCoordsComponentsType OIV.Inventor.SbDataType.DataTypes.FLOAT
texCoordsStride 0
texCoordsOffset 0
texCoordsComponentsCount 2
primitiveRestartEnabled false
primitiveRestartValue -1
}

ACTION BEHAVIOR

OIV.Inventor.Actions.SoGLRenderAction, OIV.Inventor.Actions.SoCallbackAction, SoBoundingBoxAction Do the actual rendering / bounding box computation.

See Also