A number of 3D geo-browsers, both open source as well as part of proprietary GIS enterprise solutions, are used during the daily practice to access to geospatial data, available within SDIs, via OGC-compliant web-services. However simple data access is not sufficient for complex tasks such as those required for planning or management of environmental resources. These tasks in fact often require the availability of geo-processing functionalities of various type for statistical, analytical or geographical functionalities. These processes, although typical of standard GIS solutions, are not available within web based 3D geobrowsers. The work illustrated within this paper has brought to the development of a 3D geobrowser, based on Open Source technologies, which can be used to access interactively geospatial information available within the SDIs. Additionally the application can also be used to access processing services exposed through the network in an interoperable form and made available within the SDI as Web Processing Services (WPS). When the user connects to the remote computer exposing the WPS services, the client automatically populates its graphical user interface with building blocks representing the processing services available. The user can then interactively select processing units from the menu and he/she can drag and drop them within the 3D scene. Each component, representing a processing service, is rendered as a placemark illustrating its functions. Further each component has a number of input and output slots. These represent the data type(s) accepted by the process as input and the result(s) produced as output. A symbol, rendered on top of them, informs the user about the data type accepted (e.g. shape file, numerical value, image etc.). The user can then connect compatible in- and out-slots to create complex process chains directly within the 3D scene. To do so the user drags a data slot close to a compatible connector until the system links them. This way the user can orchestrate available processing services to create complex process chains in a very user-friendly manner. Existing connections can be also broken to and re-arranged to the accommodate for the various user needs. The user can also provide the information required as input via direct user feedback, for instance drawing with the mouse an area over the terrain and connecting it to a specific input slot. The latter example is typically necessary when the user needs to select an area to define a filtering region. After the process chain is created the user can activate the process sequence. This operation is performed at the server level asynchronously. Therefore the user can continue with his/her tasks without experiencing interruptions or decrease in performance. The result of the process is then returned to the user within the 3D web client application and made visible within the 3D scene. The paper will eventually show the example of a complex analysis within a real data set and it will discuss major benefits and limitations of the approach proposed.