SLIDE 1
The problem
What we want?
better graphics better frame rate
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Introduction to normal mapping Karl Tarbe Faculty of Mathematics - - PowerPoint PPT Presentation
Introduction to normal mapping Karl Tarbe Faculty of Mathematics - - PowerPoint PPT Presentation
Introduction to normal mapping Karl Tarbe Faculty of Mathematics and Computer Science October 2, 2014 The problem What we want? better graphics better frame rate Karl Tarbe Bump mapping October 2, 2014 2 / 14 Solution - More polygons!
SLIDE 2
SLIDE 3
Solution - More polygons!
What we get?
better graphics better frame rate
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SLIDE 4
Solution - More polygons!
What we get?
better graphics better frame rate
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SLIDE 5
Shading makes the difference
Example
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SLIDE 6
Bump mapping
Example from wikipedia
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SLIDE 7
Bump mapping
Example from wikipedia How to:
Simulate displacement of surface. Profit!
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SLIDE 8
Bump mapping
Example from wikipedia How to:
Simulate displacement of surface. Profit! Topic of today.
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SLIDE 9
Texture mapping
Texture Textured plane
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SLIDE 10
Normal compression
Normal vector
Three components Range −1.0 ≤ ni ≤ 1.0
- n = (x, y, z)
RGB color
Three components Range 0 ≤ ci ≤ 255
- color = (r, g, b)
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SLIDE 11
Normal compression
Normal vector
Three components Range −1.0 ≤ ni ≤ 1.0
- n = (x, y, z)
RGB color
Three components Range 0 ≤ ci ≤ 255
- color = (r, g, b)
Compression
ci = 127.5 ∗ (ni + 1.0) ni = 1 127.5 ∗ ci − 1.0
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SLIDE 12
Normal map example
3D model Corresponding normal map
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SLIDE 13
Height map
Texture Corresponding height map
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SLIDE 14
From height map to normal map
Gradient
xgrad = pix(x −1, y)−pix(x +1, y) ygrad = pix(x, y −1)−pix(x, y +1)
- n′ =
n + U · xgrad + V · ygrad
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SLIDE 15
Revisiting Blinn-Phong lighting model
Different terms
Diffuse Ambient Specular
Final equation
I = LA · MA + nT · l · LD · MD + (r T · v)c · LS · MS
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SLIDE 16
Applying normal map
How to
Choose a consistent base. Convert normal to that base. Use that normal in the lighting model.
Example from The Cg Tutorial
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SLIDE 17
Disadvantages of bump mapping
Example from wikipedia Disadvantages
Shadows Outline
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SLIDE 18
Parallax mapping
Bump mapping Parallax mapping
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