Method createPlane

src/IECoreScene/MeshPrimitive.cpp:736–805

}

MeshPrimitivePtr MeshPrimitive::createPlane( const Box2f &b, const Imath::V2i &divisions, const Canceller *canceller )
{
	V3fVectorDataPtr pData = new V3fVectorData;
	std::vector<V3f> &p = pData->writable();

	V2fVectorDataPtr uvData = new V2fVectorData;
	uvData->setInterpretation( GeometricData::UV );
	std::vector<Imath::V2f> &uvs = uvData->writable();

	// add vertices

	const float xStep = b.size().x / (float)divisions.x;
	const float yStep = b.size().y / (float)divisions.y;
	const float uStep = 1.0f / (float)divisions.x;
	const float vStep = 1.0f / (float)divisions.y;
	for ( int i = 0; i <= divisions.y; ++i )
	{
		Canceller::check( canceller );
		for ( int j = 0; j <= divisions.x; ++j )
		{
			p.push_back( V3f( b.min.x + j * xStep, b.min.y + i * yStep, 0 ) );
			uvs.push_back( V2f( j * uStep, i * vStep ) );
		}
	}

	IntVectorDataPtr vertexIds = new IntVectorData;
	IntVectorDataPtr verticesPerFace = new IntVectorData;
	std::vector<int> &vpf = verticesPerFace->writable();
	std::vector<int> &vIds = vertexIds->writable();

	// add faces
	int v0, v1, v2, v3;
	for ( int i = 0; i < divisions.y; ++i )
	{
		for ( int j = 0; j < divisions.x; ++j )
		{
			Canceller::check( canceller );
			v0 = j + (divisions.x+1) * i;
			v1 = j + 1 + (divisions.x+1) * i;;
			v2 = j + 1 + (divisions.x+1) * (i+1);
			v3 = j + (divisions.x+1) * (i+1);

			vpf.push_back( 4 );
			vIds.push_back( v0 );
			vIds.push_back( v1 );
			vIds.push_back( v2 );
			vIds.push_back( v3 );
		}
	}

	MeshPrimitivePtr result = new MeshPrimitive( verticesPerFace, vertexIds, "linear", pData );
	// We could use Vertex interpolation here, since that's logicaly the same
	// as FaceVarying interpolation using `vertexIds` as the indices. We don't
	// do that for a few reasons :
	//
	//   - Most DCCs represent UVs using explicit indices anyway
	//   - Some of our code is currently incompatible with Vertex UVs
	//   - This gives us extra test coverage for indexed UVs "for free",