More Surfacing

Under the Surfaces panel in Layout you can apply different 'image maps' to an object.

The simplest mapping is to take an existing image (Inspire comes with many useful ones) and 'map' it onto a surface. E.g. a screenshot from a computer can be saved as an image file and then mapped on to the surface of a model of a computer monitor. Do this by clicking on the Texture button next to the Surface Colour attribute, then loading the image. Select the right kind of image map for the model (planar for a flat surface, cylindrical for a cylinder...).

One of the most important things with surfacing is just naming them correctly in Modeler. Select the polygons you want to apply a particular surface to then give them a good surface name. If you have no polygons selected, it will apply the surface to all of the polygons in the layer.

Bump Maps give an object a bumpy look -and can be either image-based (bumps are based on the luminosity values in an image) or procedural (a built-in procedure defines the bumps). Either way, there are some useful settings that can be adjusted.
Perhaps most important is the "Texture Size" setting which defines how big the bumps are. A small number might be used for an orange peel or carpet, whereas a large value might be useful for terrain (more gentle undulations). As always, experiment to see what looks best.
Texture Amplitude determines the height of the bump (can be greater than 100%).
Frequencies specifies the complexity of the pattern (more than 6 is not useful for bump maps).

It is important to note that a bump map does not change an object's geometry, it just changes its appearance (surface properties).
Some times you want to make an object's geometry change without actually replacing the object- perhaps over time. This can be done with Displacement Mapping. This process modifies the polygons in the object according to an image map or a procedure (as for bump mapping above). The parameters are similar, but an Envelope can be used to make the change have different values at different times (for example to animate an object bulging or blowing up).

Because displacement mapping applies to the individual polygons in the object, you must have lots of different polygons (preferably triangles) in the object. E.g. for a flat box, Triple it in Modeler (T), then SubDivide (D) it to turn each triangle into multiple triangles. D it several times until you have enough polygons. If you need more, go back and do more subdividing in Modeler, then in Layout you can Replace the object with the new one - from the Objects panel.