1. GM(Graphics Masters) CSE 20011266 이동형 CSE 20021139 최태준 CSE 20061174 신재훈

2.  A type of NPR(Non-photorealistic rendering )  Describes object using parallel or cross lines  Contour, tone, and curvature are represented by those lines.  Density of lines and their overlaps are major factors to consider in implementing hatching.

3.  Picture from Wikipedia

4.  OpenGL  Visual Studio 2005  C++  Other Resources  OBJ files  Jpeg decoder : CxImage Library  GTS Library(GNU Triangulated Surface Library)  Tone Texture : RenderMonkey SDK  OBJ2GTS : Selfmade App For Converting

5.  Major Issues  Contour  Tone  Curvature  Our Own Features  Speed Lines  Animation Tests

6.  Contour shaking  Multiple Contour drawing  Picture from “Real-Time Pencil Rendering”

7.  Detection Contour 1. Select two faces 2. Check angle between two faces using Normal Vector 3. If angle < 150 then If two faces share same edge then Assign Contour - Additional Check Routine : Suggestive contours for conveying shape  Draw Contour 1. Draw additional two lines 2. Edge’s Vertex(x,y,z) => Line’s Vertex(x+r, y+r, z+r) 3. r = -0.002 ~ +0.002

9.  Discrete multiple level of tones  Mipmap for scaling  Interpolation at each vertex  Picture from “Real-Time Hatching”

10. Weight : 0 Weigh : 1 Weight : 2 Weight : 3 Weigh : 4 Weight : 5

11. For each Face For each Vertex 1) v = Normalize(VertexCoord – LightCoord) 2) n = VertexNormalVector 3) result = (v.DotProduct(n) + 1.0f) * 3.0f 4) weighting(result) Weight => 0.0 ~ 6.0 5) Blend Texture Image - MultiTexture If weight is 3.4 => weight 3 : 60%, weight 4 : 40% If weight is 5.5 => weight 5 : 50%, weight 5 : 50%

13.  Rotate textures for voluminousness  3-way Blending Each Vertex Per Face - Compute principal direction  Use GNU Triangulated Surface Library(http://gts.sourceforge.net/)http://gts.sourceforge.net/ * From “Real-Time Pencil Rendering” paper

14. For each Face For each Vertex 1) Get Principal Directions of Vertex 2) angle = arctan(y / x) x : x of principal directions y : y of principal directions 3) Rotate texture by angle 4) Texture Mapping

16.  To express speed effectively in hatching, we used extra lines.  The faster object moves, the longer lines are drawn.  Speed line is expressed with gradation to express gradual speed change

18.  Flag animation is rendered to show that hatching can well render dynamic scenes.  Flag is set by basic rectangular lattice.  Flag animation is done as z value changes along sin function.  Like water animation.

20.  Any questions?