3D terrain production from GIS data

• I want someone to develop a simple workflow that I can follow to produce 3D terrain images. • This needs to be clear, step by step instructions for someone not experienced with GIS data or programs. The workflow will contain screenshots and/or a screen capture movie showing all the necessary steps. • I want to use UK OS terrain50 data to provide the initial GIS data (available for free download here [login to view URL]) • I would like the image to show hillshade AND contours • I want to use QGIS (with blender?) or another free to use software package. • I am working on a Mac, OS 10.13.3 and I have installed QGIS 2.18.15 • I want to be able to centre the viewer image within the scene: The QGIS Qgis2threejs plugin gives the kind of 3D output I want but the view of the terrain is from an external position: I want to be able to position the viewpoint within the scene so that it is possible to rotate the scene around this point, giving the impression of the view from that spot. I know it is possible to do this within ArcGis using ArcScene with the "set observer" command (but I don't want to use ArcGis as I can't afford it!). • I want to be able to save the resulting viewer centred scene in a format that can be incorporated into a website (eg VRML or the output type that is produced by Qgis2threejs) as I will want to put this into a website in the next stage of my project. • As an example, I would like to use the GIS data for tile SH65 from the OS Terrain 50 data and centre the viewer at 265829, 354174