thothbot.parallax.core.shared.core

Class BufferGeometry

java.lang.Object

thothbot.parallax.core.client.renderers.WebGLGeometry

thothbot.parallax.core.shared.core.AbstractGeometry

thothbot.parallax.core.shared.core.BufferGeometry

Direct Known Subclasses:

PlaneBufferGeometry

public class BufferGeometry
extends AbstractGeometry

This class is an efficient alternative to Geometry, because it stores all data, including vertex positions, face indices, normals, colors, UVs, and custom attributes within buffers; this reduces the cost of passing all this data to the GPU. This also makes BufferGeometry harder to work with than Geometry; rather than accessing position data as Vector3 objects, color data as Color objects, and so on, you have to access the raw data from the appropriate attribute buffer BufferAttribute.

 BufferGeometry geometry = new BufferGeometry();

 int chunkSize = 20000;

 // three components per vertex
 int triangles = 160000;
 Uint16Array indices = Uint16Array.create( triangles * 3 );

 for ( int i = 0; i < indices.getLength(); i ++ ) 
 {
                indices.set( i, i % ( 3 * chunkSize ));
 }

 Float32Array positions = Float32Array.create( triangles * 3 * 3 );

 //itemSize = 3 because there are 3 values (components) per vertex
 geometry.addAttribute( "position", new BufferAttribute( positions, 3 ) );

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BufferGeometry.DrawCall

Field Summary

Fields inherited from class thothbot.parallax.core.client.renderers.WebGLGeometry

__colorArray, __lineDistanceArray, __normalArray, __tangentArray, __uv2Array, __uvArray, __vertexArray, __webglColorBuffer, __webglCustomAttributesList, __webglFaceBuffer, __webglFaceCount, __webglInit, __webglLineBuffer, __webglLineCount, __webglLineDistanceBuffer, __webglMorphNormalsBuffers, __webglMorphTargetsBuffers, __webglNormalBuffer, __webglParticleCount, __webglSkinIndicesBuffer, __webglSkinWeightsBuffer, __webglTangentBuffer, __webglUV2Buffer, __webglUVBuffer, __webglVertexBuffer, __webglVertexCount

Constructor Summary

Constructors

Constructor and Description
BufferGeometry()

Method Summary

Modifier and Type	Method and Description
void	addAttribute(java.lang.String name, BufferAttribute attribute) WebGL stores data associated with individual vertices of a geometry in attributes.
void	addDrawCall(int start, int count)
void	addDrawCall(int start, int count, int indexOffset)
void	applyMatrix(Matrix4 matrix) Bakes matrix transform directly into vertex coordinates.
BufferGeometry	clone()
void	computeBoundingBox() Computes bounding box of the geometry, updating Geometry.boundingBox attribute.
void	computeBoundingSphere() Computes bounding sphere of the geometry, updating Geometry.boundingSphere attribute.
java.util.List<BufferGeometry.DrawCall>	computeOffsets()
java.util.List<BufferGeometry.DrawCall>	computeOffsets(int size) Compute the draw offset for large models by chunking the index buffer into chunks of 65k addressable vertices.
void	computeTangents() Computes vertex tangents.
void	computeVertexNormals() Computes vertex normals by averaging face normals.
BufferGeometry	fromGeometry(Geometry geometry) Populates this BufferGeometry with data from a Geometry object.
BufferGeometry	fromGeometry(Geometry geometry, Material.COLORS vertexColors)
BufferAttribute	getAttribute(java.lang.String name)
java.util.Map<java.lang.String,BufferAttribute>	getAttributes()
java.util.List<BufferGeometry.DrawCall>	getDrawcalls() For geometries that use indexed triangles, this Array can be used to split the object into multiple WebGL draw calls.
void	normalizeNormals() Every normal vector in a geometry will have a magnitude of 1.
void	reorderBuffers(Float32Array indexBuffer, Int32Array indexMap, int vertexCount)
void	setDirectBuffers(WebGLRenderingContext gl)
void	setDrawcalls(java.util.List<BufferGeometry.DrawCall> drawcalls)
java.lang.String	toString()

Methods inherited from class thothbot.parallax.core.shared.core.AbstractGeometry

getBoundingBox, getBoundingSphere, getId, getName, isColorsNeedUpdate, isElementsNeedUpdate, isGroupsNeedUpdate, isLineDistancesNeedUpdate, isMorphTargetsNeedUpdate, isNormalsNeedUpdate, isTangentsNeedUpdate, isUvsNeedUpdate, isVerticesNeedUpdate, setBoundingBox, setBoundingSphere, setColorsNeedUpdate, setElementsNeedUpdate, setGroupsNeedUpdate, setId, setLineDistancesNeedUpdate, setMorphTargetsNeedUpdate, setName, setNormalsNeedUpdate, setTangentsNeedUpdate, setUvsNeedUpdate, setVerticesNeedUpdate

Methods inherited from class thothbot.parallax.core.client.renderers.WebGLGeometry

dispose

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

BufferGeometry

public BufferGeometry()

Method Detail

getAttributes

public java.util.Map<java.lang.String,BufferAttribute> getAttributes()

addAttribute

public void addAttribute(java.lang.String name,
                         BufferAttribute attribute)

WebGL stores data associated with individual vertices of a geometry in attributes. Examples include the position of the vertex, the normal vector for the vertex, the vertex color, and so on. When using Geometry, the renderer takes care of wrapping up this information into typed array buffers and sending this data to the shader. With BufferGeometry, all of this data is stored in buffers associated with an individual attributes. This means that to get the position data associated with a vertex (for instance), you must call .getAttribute() to access the "position" attribute, then access the individual x, y, and z coordinates of the position.

The following attributes are set by various members of this class:

• position - Stores the x, y, and z coordinates of each vertex in this geometry. Set by .fromGeometry().
• normal - Stores the x, y, and z components of the face or vertex normal vector of each vertex in this geometry. Set by .fromGeometry().
• color - Stores the red, green, and blue channels of vertex color of each vertex in this geometry. Set by .fromGeometry().
• tangent - Stores the x, y, and z components of the tangent vector of each vertex in this geometry. Set by .computeTangents().
• index - Allows for vertices to be re-used across multiple triangles; this is called using "indexed triangles," and works much the same as it does in Geometry: each triangle is associated with the index of three vertices. This attribute therefore stores the index of each vertex for each triangular face. If this attribute is not set, the renderer assumes that each three contiguous positions represent a single triangle.

Parameters:

name - Attribute name

attribute -

getAttribute

public BufferAttribute getAttribute(java.lang.String name)

getDrawcalls

public java.util.List<BufferGeometry.DrawCall> getDrawcalls()

For geometries that use indexed triangles, this Array can be used to split the object into multiple WebGL draw calls. Each draw call will draw some subset of the vertices in this geometry using the configured shader. This may be necessary if, for instance, you have more than 65535 vertices in your object.

Returns:

setDrawcalls

public void setDrawcalls(java.util.List<BufferGeometry.DrawCall> drawcalls)

Parameters:

drawcalls - the drawcalls to set

addDrawCall

public void addDrawCall(int start,
                        int count)

addDrawCall

public void addDrawCall(int start,
                        int count,
                        int indexOffset)

applyMatrix

public void applyMatrix(Matrix4 matrix)

Bakes matrix transform directly into vertex coordinates.

Parameters:

matrix -

fromGeometry

public BufferGeometry fromGeometry(Geometry geometry)

Populates this BufferGeometry with data from a Geometry object.

Parameters:

geometry -

Returns:

fromGeometry

public BufferGeometry fromGeometry(Geometry geometry,
                                   Material.COLORS vertexColors)

computeBoundingBox

public void computeBoundingBox()

Computes bounding box of the geometry, updating Geometry.boundingBox attribute. Bounding boxes aren't computed by default. They need to be explicitly computed, otherwise they are null.

Specified by:

computeBoundingBox in class AbstractGeometry

computeBoundingSphere

public void computeBoundingSphere()

Computes bounding sphere of the geometry, updating Geometry.boundingSphere attribute. Bounding spheres aren't computed by default. They need to be explicitly computed, otherwise they are null.

Specified by:

computeBoundingSphere in class AbstractGeometry

computeVertexNormals

public void computeVertexNormals()

Computes vertex normals by averaging face normals.

Specified by:

computeVertexNormals in class AbstractGeometry

computeTangents

public void computeTangents()

Computes vertex tangents. Based on http://www.terathon.com/code/tangent.html Geometry must have vertex UVs (layer 0 will be used).

Specified by:

computeTangents in class AbstractGeometry

computeOffsets

public java.util.List<BufferGeometry.DrawCall> computeOffsets()

computeOffsets

public java.util.List<BufferGeometry.DrawCall> computeOffsets(int size)

Compute the draw offset for large models by chunking the index buffer into chunks of 65k addressable vertices. This method will effectively rewrite the index buffer and remap all attributes to match the new indices. WARNING: This method will also expand the vertex count to prevent sprawled triangles across draw offsets

Parameters:

size - Defaults to 65535, but allows for larger or smaller chunks.

Returns:

normalizeNormals

public void normalizeNormals()

Every normal vector in a geometry will have a magnitude of 1. This will correct lighting on the geometry surfaces.

reorderBuffers

public void reorderBuffers(Float32Array indexBuffer,
                           Int32Array indexMap,
                           int vertexCount)

clone

public BufferGeometry clone()

Overrides:

clone in class java.lang.Object

setDirectBuffers

public void setDirectBuffers(WebGLRenderingContext gl)

toString

public java.lang.String toString()

Overrides:

toString in class AbstractGeometry