Illustrative textures, such as stippling or hatching, were predominantly used as an alternative to conventional Phong rendering. Recently, the potential of encoding information on surfaces or maps using different densities has also been recognized. This has the significant advantage that additional color can be used as another visual channel and the illustrative textures can then be overlaid. Effectively, it is thus possible to display multiple information, such as two different scalar fields on surfaces simultaneously. In previous work, these textures were manually generated and the choice of density was unempirically determined. Here, we first want to determine and understand the perceptual space of illustrative textures. We chose a succession of simplices with increasing dimensions as primitives for our textures: Dots, lines, and triangles. Thus, we explore the texture types of stippling, hatching, and triangles. We create a range of textures by sampling the density space uniformly. Then, we conduct three perceptual studies in which the participants performed pairwise comparisons for each texture type. We use multidimensional scaling (MDS) to analyze the perceptual spaces per category. The perception of stippling and triangles seems relatively similar. Both are adequately described by a 1D manifold in 2D space. The perceptual space of hatching consists of two main clusters: Crosshatched textures, and textures with only one hatching direction. However, the perception of hatching textures with only one hatching direction is similar to the perception of stippling and triangles. Based on our findings, we construct perceptually uniform illustrative textures. Afterwards, we provide concrete application examples for the constructed textures.

翻译：说明性纹理（如点画或阴影线）主要被用作传统冯氏渲染的替代方式。近年来，利用不同密度在表面或地图上编码信息的潜力也得到认可。其显著优势在于可将额外颜色用作另一视觉通道，并叠加说明性纹理。因此，实际上可以同时显示多种信息，例如在表面上显示两个不同的标量场。以往工作中，这些纹理是手动生成的，且密度选择未经经验确定。在此，我们首先希望确定并理解说明性纹理的感知空间。我们选择维度递增的一系列单纯形作为纹理基元：点、线、三角形。由此探索点画、阴影线和三角形三种纹理类型。通过均匀采样密度空间，我们生成一系列纹理。随后进行三项感知研究，参与者对每种纹理类型进行成对比较。我们采用多维缩放（MDS）分析各类别的感知空间。点画和三角形的感知似乎相对相似，两者均由二维空间中的一维流形充分描述。阴影线的感知空间包含两个主要簇：交叉阴影线纹理和仅含单一阴影方向的纹理。然而，仅含单一阴影方向的阴影线纹理的感知与点画和三角形相似。基于我们的发现，我们构建了感知一致的说明性纹理。随后，为所构建的纹理提供具体应用示例。