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基于Wang Tiles的几何纹理合成 总被引:1,自引:0,他引:1
提出了一种基于Wang Tiles的几何纹理合成方法来在不同物体表面上即时地生成几何纹理.首先根据给定的几何纹理预计算出一组Wang Tiles,然后用这组Wang Tiles在不同的目标物体上即时生成新的几何纹理.尽管基于Wang Tiles的方法已经应用于图像纹理,但由于几何纹理采用了与图像纹理完全不同的表示方式,因此需要用完全不同的方法来处理.采用了基于约束的几何纹理合成技术自动生成几何纹理Wang Tiles,从而保证了生成的几何纹理Wang Tiles在所有排列下都能保持其几何连续性.与现有的方法相比,生成的几何纹理Wang Tiles可以重用到不同的目标物体上,同时占用的存储空间及计算量更小,速度更快. 相似文献
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An enduring mystery in biology is how a physical entity simple enough to have arisen spontaneously could have evolved into
the complex life seen on Earth today. Cairns-Smith has proposed that life might have originated in clays which stored genomes
consisting of an arrangement of crystal monomers that was replicated during growth. While a clay genome is simple enough to
have conceivably arisen spontaneously, it is not obvious how it might have produced more complex forms as a result of evolution.
Here, we examine this possibility in the tile assembly model, a generalized model of crystal growth that has been used to
study the self-assembly of DNA tiles. We describe hypothetical crystals for which evolution of complex crystal sequences is
driven by the scarceness of resources required for growth. We show how, under certain circumstances, crystal growth that performs
computation can predict which resources are abundant. In such cases, crystals executing programs that make these predictions
most accurately will grow fastest. Since crystals can perform universal computation, the complexity of computation that can
be used to optimize growth is unbounded. To the extent that lessons derived from the tile assembly model might be applicable
to mineral crystals, our results suggest that resource scarcity could conceivably have provided the evolutionary pressures
necessary to produce complex clay genomes that sense and respond to changes in their environment.
相似文献
Erik Winfree (Corresponding author)Email: |
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我国南方应用较广的GKP外墙外保温薄抹灰贴面砖出现大面积开裂、脱落问题较多.作者针对这一现象从施工的角度提出解决方法,以供同行参考. 相似文献
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针对目前建筑信息模型(BIM)与地理信息系统(GIS)集成方案网络传输与浏览器渲染能力的不足,选择GIS领域更适合Web端加载的三维瓦片数据作为研究目标,提出BIM模型从工业基础类(IFC)向3D Tiles数据格式的转化方法和在Web端快速加载BIM模型的思路,并对GIS和BIM在Web端的大体量数据集成方案进行研究. 针对IFC标准模型数据,根据建筑构件划分标准对数据进行拆分,得到几何信息文件和语义属性文件. 几何信息文件经中间格式转换,最终与语义属性文件封装为保留有BIM语义属性的三维瓦片数据. 在转换过程中完成了坐标转换、数据映射、空间索引以及多细节层级(LOD)划分,实现了BIM数据和地理要素数据在三维WebGIS框架下快速、高效的渲染交互. 相似文献
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以南方某稀土尾矿为主要原料,添加部分瓷土等其它条件,制备了色彩均匀的紫砂红地砖,其性能超过了国家标准GB11947-89等所规定的性能指标。 相似文献
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Z. Shu J. Garcia-TenE. Monfort J.L. AmorosJ. Zhou Y.X. Wang 《Ceramics International》2012,38(2):1479-1487
A new ceramic powder preparation process, the droplet-powder granulation process (DPGP), was recently proposed for the cleaner production of ceramic tiles. The DPGP granules and resulting pressed compacts were characterized and compared with the granules and compacts obtained by spray-drying (SD) and dry granulation (G) processes in a previous paper. The results showed the feasibility of using the DPGP in the pre-firing stage of porcelain tile manufacture.This study compares the firing behaviour and fired properties of compacts pressed from three different types of granulated powders: DPGP, SD, and G and from a non-granulated powder (NG) obtained by dry milling. The evolution of compact microstructure (porosity and pore size distribution) with firing temperature was monitored and the fired compact properties (bulk density, water absorption, and stain resistance) were determined.The study shows that the DPGP improved the sintering behaviour and final properties of the resulting porcelain tiles with respect to those obtained by the G process. However, the fired compacts prepared from the DPGP powder exhibited a higher porosity and pore size compared with those of the compacts obtained from the SD granules at the same pressing pressure. The results obtained open up the possibility of manufacturing glazed porcelain tiles with a more eco-friendly process. However, the results also indicate that polished porcelain tile manufacture by the DPGP requires further research in order to improve granule characteristics, in particular green granule deformability, which is the critical factor in porcelain tile densification and vitrification during firing. 相似文献
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如何在纹理样图中选择组成Wang Tiles的图像块决定着纹理的合成质量。基于PSO的Wang Tiles纹理合成通过粒子群优化算法在纹理样图中快速搜索边界差异最小的图像块,并用选取的图像块构建Wang Tiles,最后用Wang Tiles纹理合成算法合成纹理。实验表明,该算法合成的纹理具有较少的接缝,比随机选择图像块具有更好的合成效果。 相似文献
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