In computer graphics a projection describes the mapping of scene geometry to the screen. While linear projections such as perspective and orthographic projection are common, increasing applications are being found for nonlinear projections, which do not necessarily map straight lines in the scene to straight lines on the screen. Nonlinear projections occur in reflections and refractions on curved surfaces, in art, and in visualisation. This thesis presents a new nonlinear projection technique called a trilinear projection that is based on the trilinear interpolation of surface normals used in Phong shading. Trilinear projections can be combined to represent more complicated nonlinear projections. Nonlinear projections have previously been implemented with ray tracing, where rays are generated by the nonlinear projections and traced into the scene. However for performance reasons, most current graphics software uses scanline rendering, where a scene point is imaged on a screen as a function of the projection parameters. The techniques developed in this thesis are of this nature. This thesis presents several algorithms used in trilinear projection: 1. An algorithm to analytically determine which screen locations image a given scene point. 2. An algorithm that correctly connects projected vertices. Each scene point may be imaged multiple times, which means a projected scene triangle may form from one to four different shapes of from two to nine vertices. Once connected, the projected shapes may be rendered with standard scanline algorithms. 3. An algorithm to more accurately render the curved edges between projected vertices. 4. A scene-space edge-clipping algorithm that handles continuity issues for projected shapes across composite projections. The trilinear projection technique is demonstrated in two different application areas: visualisation, and reflections and refractions. Specifically, various nonlinear projections that are congruent with pre-existing visualisation techniques are implemented with trilinear projections and a method for approximating the reflections and refractions on curved surfaces with trilinear projections is presented. Finally, the performance characteristics of the trilinear projection is explored over various parameter ranges and compared with a naive ray tracing approach.

Throughout the reading process, a narrative text produces various sensations of immediacy or distance. One important reason for this is that a narrative will in some places present situtations from a particular perspective, with which the reader is implicitly invited to identify, while in other places it will describe situations as independent of any perspective. If a perspective (that of the narrator, or that of a character in the text) is introduced, the narrative reflects an individual's (potentially fallible) perceptions, attitudes or beliefs; and this creates the impression of perspectival immediacy. If no perspective is introduced, on the other hand, the narrative pretends to relate "objective facts" within the fiction; and this creates the impression of perspectival distance. Thus the contrast between perepectivally situated and perepectivally non-situated sentences in a narrative produces perspectival refractions. The difference between both types of sentences, however, is often felt to be recalcitrant to a full linguistic analysis. For example, it is generally assumed that the perspectival status of a sentence is determined by the presence or absence of aubject-oriented elements in the sentence. But although such elements play an important role in focusing perspective, they need not occur in a sentence for the sentence to be perspectivally situated. In Chapter 1 of this dissertation, we draw attention to an observation which has received very little attention in the existing literature on perspective: per pectivally non-situated sentences typically move narrative time forward (in the sense that the order of the sentences on the page mimics temporal progression on the imaginary time line of the narrative), while perspectivally situated sentences do not convey forward movement in time. In other words, there appears to be a relationship between temporal ordering and perspective. Our aim is to specify the precise nature of this relationship. To do so, we first of all try to establish what determines the temporal relationship between consecutive sentences in narrative. We take as the starting point for our discussion some recent theories in the field of formal semantics which define this relationship in terms of the aspectual type a sentence belongs to. In Chapter 2, we explore to what extent these theories enable us to explain the apparent correlation between temporal ordering and perspective in narrative texts. In Chapters 3-5, we propose a detailed analysis of the relationship between the aspectual properties of sentences and their perspectival characteristics. Our central claim is that sentences exhibiting a state profile always introduce a perspective into a narrative. We try to make explicit why this is the case. In Chapter 6, the conclusions of this analysis are integrated into a more general theory of perspective in narrative fiction.

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The sight of work is study form high frequency electromagnetic wave in inhomogeneous materials. The main are refractions and reflection on boundary of materials with different properties and form electromagnetic wave in periodic structure. The work contain analytic and numeric solution. The numeric solution was realized in program COMSOL.