bull n. 1.公牛;雄象,雄鯨;雄性大動物。 2.軀體龐大的人,粗壯的人;〔美俚〕工頭;農(nóng)場監(jiān)工;〔美俚〕火車頭。 3.〔B-〕=John Bull 【天文學】金牛宮,金牛座。 4.(股票投機中的)買方,多頭 (opp. bear). 5.〔美俚〕警察;偵探。 6.瞎話,大話。 7.〔英俚〕(舊制)五先令銀幣。 an elephant bull雄象。 He had a mother's soul in a body of bull 他身體粗壯而心地善良。 a china-shop bull 動輒闖禍的粗人,瓷器店里的大象。 bull in the ring (小孩子玩的)突圍游戲。 like a bull at a (five-barred) gate 狂怒地,猛烈地,兇猛地。 milk the bull 做徒勞無功的事,想從公牛身上擠奶。 take the bull by the horns 挺身面對危險,毅然處理難局;(斗牛士)敢抓公牛角。 throw the bull 吹牛,胡說八道。 adj. 1.雄的,公的;公牛一樣的。 2.【商業(yè)】買方的,哄臺證券價格的。 movement (股票投機中)哄抬行情的活動,買方[多方]的策動。 a bull head 公牛一樣的頭[頸,嗓音]。 a bull whale 公鯨。 vi. 1.哄抬證券價格,做多頭,做買方。 2.〔美俚〕排除困難前進,奮力前行。 3.〔美俚〕夸口,吹牛,自大,說空話。 4.〔俚語〕配種,交尾。 bullthrough the crowd 從人群中擠過去。 vt. 1.哄抬(證券等的行情)。 2.強行通過(議案等),擠出(路等)。 3.【航?!?以船首)猛撞。 bullstocks 哄抬股票行情。 bulla bill through congress 在議會中強行通過一項議案。 bullone's way through the crowd 從人群中擠出一條路。 n. (羅馬教皇的)訓諭,訓令。 n. 滑稽的矛盾,可笑的錯誤。
In this paper , i will present some algorithms of polyhedral visual hull reconstruction : ( 1 ) polyhedral v isual h ull generation a igorithm b ased one dge - pool - searching , which constrains the 3 - d intersections into the 2 - d planes intersection via the epipolar theory to reduce the complexity a nd c an r educe t he t imes f or c ones t o b e p rejected o nto t he i mage p lanes , i n which we induced the index list to every points on the surface of object , and connected the related points to get sub polygons on surface and in turn get the mesh model , we replace triangulation process of disordered points cloud by edge - pool searching . ; ( 2 ) reconstruction based on degenerated - polygon - intersection , which have the following improvements on traditional bull intersection : using degenerated polygon to orga nize intersected area on cone face , which may be discontinuous ; a fast intersection algorithm of polygons on the cone face based on degenerated polygons , which is consistent between the continuous polygons and the discontinuous ones . the intersection of degenerated polygons is similar to the convergence of two ordered lists , which is comparably simple to the bull operation ; ( 3 ) reconstruction algorithm based on ray - tracing , in which all the rays that run through the vertex on silhouette of object will intersect with all the cones correspondent to other silhouette , and we have to calculate the intersection of all such line segments , the endpoints of which are considered to lie on the surface of object and we will get the point cloud on the surface of object 同時利用共極線原理把三維計算投影到二維平面以降低求交計算的復雜度,該算法可以減少光錐向圖像平面投影計算的次數(shù),以邊池搜索取代散亂點集上進行的三角剖分; ( 2 )基于退化多邊形求交的多面體可見殼模型重構(gòu),系統(tǒng)引入退化多邊形的概念,把錐體平面的交集中不連通的部分用一個退化多邊形來表示,并引入了新的基于退化多邊形的求交算法,與傳統(tǒng)多面體可見殼重構(gòu)相比,該算法有以下幾點創(chuàng)新:在圖像平面以退化多邊形組織投影錐體和物體輪廓的交集,把任意錐面與物體輪廓的交集歸一到一個退化多邊形;基于退化多邊形的二維平面上多邊形快速相交算法,該算法在一定程度上就是兩個有序鏈表的合并,大大簡化了先前的布爾求交計算; ( 3 )基于光線跟蹤的算法,該算法中所有通過輪廓頂點的光線和對應其它圖像輪廓的光錐進行求交計算,最后得到每次求交計算得到線段的交集,該線段的頂點就認為是物體表面點,從而得到物體表面的點云。