The second area covered in the advanced mapping section will be looking at displacement mapping. This sort of mapping works similar to bump mapping which was covered in the first artefact, in the way it works of making a flat surface made to look like it has a uneven one. However displacement maps physically makes a flat surface indeed look irregular. The example below shows the initial plane with a metal like texture and also a black and white peace sign which will be the displacement map.
The black and white displacement map works in the same way as a bump map where the colour decides what section of a map will be displaced on an object. In this case the black area shall be unaffected whilst the white section will be altered. First of to see how the displacement alters an objects geometry a bump map will be placed onto the surface first and a comparison can be made.
The bump map effects are very subtle, the objects surface looks like it has been embossed with peace sign and the black outline that has been created shows the difference in height. Now comparing this to the displacement map (note both the bump and displacement map are both the same to remain consistent) the embossed area looks far definitive and the height of the object can be seen more clearly than previously with the bump map. A fine quality that displacement mapping possesses is that when the object has been embossed the polygon count will be unaffected. This can be highly beneficial in a complex scene where there are many objects.
At this point peers were asked if the displacement map looks more definitive than the previous bump map and all of them agreed, however a handful suggested if the scene had both displacement and bump maps present and this was done in the next step and the resulted render can be seen below.
The same peers were asked if the new image gives the impression of being more realistic than the previous displacement map rendered image. As the bump map gives a definitive shaded area around the peace sign the geometry looks uplifted and embossed with more quality. The peers gave a similar contribution to my thoughts and are much more positive with the final result. From this procedure the results have been constructive the use of displacement mapping can significantly alter the geometry of an object without using more polygons which is a benefit as it allows a user to create complex scene with less effort for the renderer.
