.NET (Core and Framework)

MeshGeometry3D plane = new MeshGeometry3D();
Point3DCollection points = new Point3DCollection();
points.Add(new Point3D(p1X, p1Y, p1Z));
points.Add(new Point3D(p2X, p2Y, p2Z));
points.Add(new Point3D(p3X, p3Y, p3Z));
points.Add(new Point3D(p4X, p4Y, p4Z));
plane.Positions = points;
Int32Collection indices = new Int32Collection();
indices.Add(0);
indices.Add(1);
indices.Add(2);
indices.Add(0);
indices.Add(2);
indices.Add(3);
plane.TriangleIndices = indices;
PointCollection texturePoints = new PointCollection();
texturePoints.Add(new Point(0, 0));
texturePoints.Add(new Point(0, 1));
texturePoints.Add(new Point(1, 1));
texturePoints.Add(new Point(1, 0));
plane.TextureCoordinates = texturePoints;

ImageBrush brush = new ImageBrush();
brush.ImageSource = new BitmapImage(new Uri(@"C:\test1.jpg"));
DiffuseMaterial material = new DiffuseMaterial(brush);

GeometryModel3D result = new GeometryModel3D(plane, material);