Geometric Error

We would like to compare the results of our decimation program with other programs that simplify meshes. With the help of to important papers in mesh simplification[#metro##1###,#!evaluation!#], we were allowed to do this. First, we generated eight levels of detail for the Stanford bunny model using our decimation program, removing 50% of the vertices from the previous level of detail in each run of the program. Next, in order to compute the geometric error between each level of detail and the original bunny model, we used the Metro tool[#!metro!#], producing the results shown in Table . Using the methodology and results from the memoryless simplification authors' work[#!evaluation!#] (see our Literature Review chapter), we were able to compare our results to six other programs that were used to create eight levels of detail of the same model using the same process (50% removal in each run). See our Analysis chapter for this comparison.

Table: The maximum and mean geometric error as calculated by Metro between the original Stanford bunny model and eight progressively simplified levels of detail generated with our program

The first set of images, shown in Figure , depicts the original model of a clay bunny in solid and point renderings. The model initially has 35,947 vertices and 69,451 triangle polygons. The next two sets of images show the model in eight levels of detail, removing approximately 50% of the vertices from the model at each stage, first rendered solid and then showing only points. The first level of detail and the original model look identical in these renderings, since in both cases there is more than one triangle per pixel at the resolution these images were rendered in.

The second set of images, shown in Figure , is a rendering of the solid model with no options enabled in all eight stages of decimation, removing 50% of the vertices at each stage. The original model is immense and needs a significant amount of memory and CPU power to load and render. The progressively decimated images have far fewer polygons, and we feel they are good visual representations of the original model, yet they render much more quickly because of the much lower polygon count.

Figure: The original bunny model rendered solid and with only points.

Figure: The bunny model rendered solid in eight levels of detail.

The last set of images, shown in Figure , is a rendering of the model showing only points in all eight stages of decimation, removing 50% of the vertices at each stage. These renderings emphasize how many fewer vertices we have during each iteration of the test.

Figure: The bunny model rendered showing only points in eight levels of detail.