learning - Academic Conferences Limited

Robert Lucas
Figure 5: A model of a Malteaser which has been cut to make it appear solid with a generated face
and a cut face texture made from a photograph of the real thing
This was good enough to fool my four and six year old into thinking it was a photograph of a real
Malteaser and there is no doubting their expertise in this area! When it was explained that it was a 3D
model and were shown it being rotated, one of them asked if it was possible to print it in such a way
as they could eat it!
Figure 6 shows the cross section of some frog skin which has been created as a model. This has
been constructed from polygons representing the main skin volume, the poisonous glands (bulbous
bottle shaped as given in figure 1) and the mucous glands (white).
Figure 6: Cross section through a frog’s skin
In this case all the textures were drawn from a diagram obtained from the internet (R Hamley 2011),
but it should be clear that the textures could have been obtained from photographs. Clearly this view
is at some higher level of magnification than normal. However, there is no reason why we cannot
include magnified views in our 3D world. The virtual spectroscope described in (Lucas 2010) includes
a telescope that is implemented using a software camera capable of yielding whatever magnification
is required of whatever it is pointed at in the virtual world.
5. Discussion and future development
There is much that can be done with what has been implemented. It certainly felt at first quite strange
to be able to cut through models that we know to be hollow and have them display internal structure
as though they are solid. Effectively it is an illusion very much like a magic trick. However, any 3D
graphics application is actually an illusion in any case! There is still some exploration to be done with
this tool as it stands without further development as the results are quite dramatic, being both visually
and intuitively appealing. We can consider dissecting objects that might be too difficult for standard
tools, such as small insects and microscopic organisms. Considering performance, the array
operations that are required to manipulate a mesh in real time have adequate performance for these
type of cutting operations on complex meshes. The Unity Scripting Reference (Unity 2011) states that
two million vertices can easily be handled within a second. As even complex models do not usually
have more than a few hundred thousand vertices, we can see that we are well within the performance
needed for real-time operation.
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