![](bg6.png)
our implementation performance is competitive
compared to that of other single-CPU
implementations.
Apart from performance aspects, we consider as
well rendering quality. Despite the discrete nature of
the surface representation, rendering quality is quite
high. Artifacts where visible along the silhouette are
due primarily to the multisampling code that we use
in our program, rather than due to the representation
or the algorithm that we use. Figure 8 shows 2
images of the dragon model, one with LoD on and
the other off.
Figure 8: Rendering with and without LoD.
4 CONCLUSION
We have discussed a framework for ray tracing of
point-based geometry. The framework addresses two
issues: how to intersect a ray with a point set, and
how to accelerate the ray-object search. Our solution
is simple to implement, as it requires neither
conversion to implicit surfaces nor tracing of non-
simple ray. Further, it shows a performance
competitive with that of other point-set ray tracer,
and produces images with acceptable ray-traced
quality.
Of course, more work remains to be done to
strengthen the research presented in this paper. We
would like to do more analysis on the optimizations
that we have presented in this paper. One particular
question we would like to have answered is: how to
determine the level in the hierarchy starting from
which we should use sphere-shape bounding volume
(rather than box-shape volume). We would also like
to investigate ways to improve memory usage and
memory cache performance, and to investigate
alternative ways, apart from looking at projected
sphere size, to decide on whether or not to recurse
further in the ray traversal of the hierarchy structure.
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