COMP SCI 559 Midterm: CS 559 Midterm-cs559-f15
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Time: 2 hrs: [xx y y % = zz%] multiple choice section. Circle or un- derline the correct answer (or answers). You do not need to provide a justi cation for your answer(s). (1) when combining transforms by multiplying the respective 4 4 matri- ces, the order of multiplication (i. e. the order of composition) typically matters. Other properties like relative distances can change, but an- gles are preserved under perspective projection. (b) the only thing that is preserved is that lines that are parallel in. 3d space remain parallel (on the display) after perspective trans- formation. Angles, however, are not preserved. (c) no; in the general case angles between lines, and even the property of lines being parallel can change after a perspective transforma- tion. In this case all the interpolated normals inside the triangle would be equal to the constant normal of every vertex. Thus, lighting computations would produce exactly the same result. (b) yes.
