3.2.3 Further Experiment of Ink
and Wash Rendering
Effect
Based on the above rendering technology of digital freehand landscape
painting using particle deposition and stacking (overlapping)
technology, we conducted further rendering experiments, such as trying
to simulate the effect of heavy freehand splash ink landscape painting
with dripping ink and vivid charm. Before rendering, it is necessary to
predict the effect of freehand brushwork (or splash ink) of digital
mountains and stones according to the presentation intention of digital
landscapes and to create the desired rendering effect of mountain and
stone models by defining the particle density, hardness and fusion
degree in the particle stacking model. Table 1 is a group of comparisons
after repeated experiments on the ink and texture effects of mountain
stones in freehand landscape painting based on the above technologies.
Each group of images is divided into two layers for comparison. The
upper layer is mainly for various pure ink rendering effects of mountain
stone models, and the lower layer is the final rendering after adding
texturing texture. Figure a shows the state when the particle softening
is - 0.9 and the density is 0.5, which is a process of particle
positioning and deposition; Figure b shows the state when the particles
soften to - 0.5 and the density is 0.5. At this time, the particles have
not been fused, and the texture and model have not been organically
combined; Figure c shows the state when the particle softening is 0 and
the density is 1. At this time, the particles have started to fuse, but
the fusion is not sufficient. There are obvious traces. The texture has
started to combine with the model, but there are still some hard edges;
Figure d shows the state when the particle softening is 0.3 and the
density is 1. At this time, the particles are further fused, and the
combination of texture and model is relatively sufficient, but the
splash effect has not been fully reflected; Figure e shows the state
when the particle softening is 0.7 and the density is 1; Figure f shows
the state when the particle softening is 1 and the density is 1.
Finally, the author repeatedly reviewed the ink splashing effect and
believed that both Figure e and Figure f were successful, and their ink
splashing effects had their own advantages, one was tight and
meticulous, and the other was loose and incisive, which could be chosen
according to personal aesthetic preferences. On the basis of Table 1,
further define and set the threshold value for the black, white and gray
layers in the alpha mask channel, and set the weight value of the
texturing texture display degree between the block gray value
130<RGB<255, where the RGB gray value below 130 is
defined as no texture display, and the rest remains unchanged. Finally,
we can render a splash ink landscape painting with a large freehand
effect, as shown in Figure 9.