VTK is a cross-platform C++ scientific visualization toolkit. wxVTK seeks to create a comprehensive set of doc/view classes to make cross-platform scientific visualization application development a snap (well almost).
The basic idea is to develop a set of view classes for the most common visualizations (color maps, contours, etc.) so that the developer needs only define the document and register the doc with wxWidgets's wxDocManager and view classes will be ready to visualize the data.
The doc/view stuff is still very much in the development stage and not ready to be used out of the box. If you just want to render into a wxWindow, you can download my wxVTKWindow class.