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.