# [osg-users] understanding one osg example

issam boughanmi amigoface at gmail.com
Wed Apr 20 08:17:29 PDT 2011

```i have followed this nice tutorial :
http://blog.goltergaul.de/2009/06/assignment-6-tank-simulation-keyboard-events/ that worked like  a charm

the i tried to import my own plane as athe ground made quickely in blender

but i have only a big green plane

this is a beginner question for sure
i have replaced this function that create the ground

> Geode* createPlane(int size, int texSize) {
> 	// vertex array
> 	Vec3Array *vertexArray = new Vec3Array();
> 	vertexArray->push_back(Vec3(-size/2,-size/2,0));
> 	vertexArray->push_back(Vec3(-size/2,size/2,0));
> 	vertexArray->push_back(Vec3(size/2,size/2,0));
> 	vertexArray->push_back(Vec3(size/2,-size/2,0));
>
> 	// face array
> 	// give indices of vertices in counter-clockwise order
> 	DrawElementsUInt *faceArray = new DrawElementsUInt(
> 	);
> 	faceArray->push_back(0);
> 	faceArray->push_back(1);
> 	faceArray->push_back(2);
> 	faceArray->push_back(3);
>
> 	// normal array
> 	// give the normals on the cube's faces
> 	Vec3Array *normalArray = new Vec3Array();
> 	normalArray->push_back(Vec3(0, 0, +1));
>
> 	// normal index
> 	// assign each vertex a normal (similar to assigning colors)
> 	TemplateIndexArray<unsigned int, Array::UIntArrayType, 24, 4> *normalIndexArray;
> 	normalIndexArray = new TemplateIndexArray<
> 		unsigned int, Array::UIntArrayType, 24, 4
> 	>();
> 	normalIndexArray->push_back(0);
> 	normalIndexArray->push_back(0);
> 	normalIndexArray->push_back(0);
> 	normalIndexArray->push_back(0);
>
> 	// texture coordinates
> 	osg::Vec2Array *texCoords = new osg::Vec2Array();
> 	texCoords->push_back(Vec2(0.0, 1.0));
> 	texCoords->push_back(Vec2(0.0, 0.0));
> 	texCoords->push_back(Vec2(1.0, 0.0));
> 	texCoords->push_back(Vec2(1.0, 1.0));
>
> 	Geometry *geometry = new Geometry();
> 	geometry->setVertexArray(vertexArray);
> 	geometry->setNormalArray(normalArray);
> 	geometry->setNormalIndices(normalIndexArray);
> 	geometry->setNormalBinding(Geometry::BIND_PER_VERTEX);
> 	geometry->setTexCoordArray(0, texCoords);
>
> 	Geode *face = new Geode();
>
> 	return face;
> }
>
by a simple  osgDB::ReadNodeFile from the blender plane

any help is welcome

thanks and good day

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