Set Camera Viewpoint in Visualiser

What I would like to do, is set the pose of my camera/viewpoint in the visualiser in absolute/world coordinates with an Affine-format `Eigen::Matrix4d` (that I already have).

I am unable to set the camera view matrix using the Visualizer class in C++ (http://www.open3d.org/docs/release/cpp_api/classopen3d_1_1visualization_1_1_visualizer.html) using the `SetViewMatrices()` function. The online documentation does not provide much information about this function, so possibly this function is not doing what i think it should.

I am able to change some viewing angles with functions like `ConvertFromViewParameters()`, `SetLookat()` and `SetUp()`, etc, but I have not wrangled these into producing the desired view, and can't seem to find any absolute/world frame position setting functions.

** To Reproduce **
Code snippet:
```
auto visualiser = std::make_shared();
Eigen::Matrix4d my_matrix4d;
// ... create some objects and do some rendering of textures
// ... set my_matrix4d with some translation/rotation
visualiser->GetViewControl().SetViewMatrices(my_matrix4d);
```

**Expected behavior**
The view in the visualiser should be at the pose corresponding to the input matrix (position corresponding to the translation component of the matrix, and rotation corresponding to the rotation component of the matrix).

**Environment (please complete the following information):**

- Operating system: Ubuntu 18.04
- Open3D version: v0.13 commit 2a284dd21855cb4ea4e997b365f3c1797143e5c6
- Is this remote workstation?: no
- How did you install Open3D?: built from source
- Compiler version (if built from source): gcc 7.5