Download presentation

Presentation is loading. Please wait.

Published byAmira Goodman Modified over 2 years ago

1
CSE 681 Texture mapping - other methods Environmental mapping Bump mapping

2
CSE 681 Review Surface Texturing u,v mapping: map 3D point within 3D surface –Quadrilateral: inverse bi-linear mapping –Spherical: e.g. lattitude-longitude – Triangulated: barycentric coordinates Mip-mapping: pre-filter texture map –Average texels, reduce resolution –Index into appropriate map based on projected pixel size

3
CSE 681 Environmental Mapping Reflect the environment off an object Procedurally Reflection_color = f(R(u,v)) Table look-up Reflection_color = table(R (u,v),R (u,v)) Use normal to index into texture that represents the environment

4
CSE 681 Procedural Environmental Mapping Simple: ray up is blue, ray down is brown Complex: compute fractal intersection Medium: use sinusoidals to interpolate between gray and silver for a chrome effect

5
CSE 681 Environmental (table-based) Mapping Use pre-constructed enclosing volume containing projected environment Hemi-cube or hemisphere Mip-mapping possible

6
CSE 681 Environmental Mapping table construction by projection

7
CSE 681 Hemi-cube projection construction method

8
CSE 681 Hemi-cube image construction method Use pictures - of sky, mountains, buildings, etc.

9
CSE 681 Hemi-cube reflectance look-up

10
CSE 681 Examples

11
CSE 681 Examples

12
CSE 681 Examples

13
CSE 681 Examples

14
CSE 681 Examples

15
CSE 681 Bump Mapping Modulate normals over surface to create visual effect of geometric detail http://www.mpi-inf.mpg.de/departments/irg3/ws0506/cg/slides/13-Texturing.pdf

16
CSE 681 Bump Mapping 1.Use grey-scale image to define height field 2.Compute gradient of height field 3.Use gradient vectors to modify normal Don’t really modify surface geometry – just pretend we do by modifying normal

17
CSE 681 Bump Mapping Surface is displaced in direction of normal according to displacement in bump table, B(u,v) O(u,v) B(u,v) O’(u,v) + =

18
CSE 681 Bump Mapping Normal Vector O(u,v) B(u,v) O’(u,v) + = Display:

19
CSE 681 Bump Mapping

20
Bump Mapping Normal Vector

22
CSE 681 Bump Mapping Normal Vector Assume B is small - too small to deal with

23
CSE 681 Bump Mapping Normal Vector = N = 0= D(u,v)

24
CSE 681 Bump mapping examples

25
CSE 681 Bump Mapping Example

Similar presentations

OK

Texture Mapping. Scope Buffers Buffers Various of graphics image Various of graphics image Texture mapping Texture mapping.

Texture Mapping. Scope Buffers Buffers Various of graphics image Various of graphics image Texture mapping Texture mapping.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on applied operational research society E paper display ppt online Ppt on obesity Ppt on first conditional exercises Ppt on travel and tourism in rajasthan Ppt on environmental degradation Ppt on db2 mainframes File type ppt on cybercrime news Powerpoint presentations free download ppt on pollution Hrm ppt on recruitment agencies