1. Basic Rendering
Techniques
Guilford County SciVis
V106.03

2. Rendering and Shading Techniques
 Rendering produces a finished
image.
 The closer the rendering is to
create a natural scene, the more
complex it is, and the longer it
takes to render the scene.
 Rendering the scene to a file may
include such things as the
background, output size,
compression, file type, and
output path.
 Rendering previews are small
and quick to check your scene
prior to doing a full render.

3. Texture Mapping
 The term texture in
3D computer graphics
refers to image
patterns rather than
the “feel” of materials.
 The most basic type of
texture is a 2D picture
(often saved as a
.jpeg, .bmp, or .tga
file), which is applied
to an object.

4. Texture Mapping
 Surfaces may have single colors or
they may have multiple color
patterns, which are commonly
referred to as textures.
 For example: wood has a
characteristic appearance
because of its varying color
patterns.
 Even materials like metals which
seen to be one color, when closely
examined, reveal varying shades
and colors mixed in random
patterns.

5. Texture Mapping
 Opacity maps control
whether a material is
opaque, transparent,
or translucent.
 Adding textures to the
object is an extremely
important part of
making objects look
real.

6. Texture Mapping
 Textures may be
acquired in different
ways.
 Most 3D programs
come with libraries
where you can
select various
materials and
patterns.
 Typically, 3D
programs allow
materials to be
added to the library

7. Acquiring Materials
 New materials can be made by
combining existing library
selections and sometimes
using “mixing formulas”
(blending) provided by other
3D artist.
 There are graphic programs
designed for creating 2D
textures (such as CorelDraw or
Photoshop) that can be found
on the Internet or through
software suppliers.

8. UV Space
 UV mapping is a way
of trying to solve the
distortion problems
that occur when
applying image maps
(textures) to complex
surfaces.
 Many 3D graphic
programs allow
texture image scaling
and placement
controls.

9. UV Space
 U represents the horizontal
component of an image. It
corresponds to the X axis
dimension in 2D coordinate
space.
 V represents the vertical
component of an image. It
corresponds to the Y axis
dimension in 2D coordinate
space.
 W represents the z axis in
3D coordinate space.

10. UV Space
 By applying UV scaling
and placement
restraints, the most
appropriate fit of the
image can be obtained.
 By manipulating UV
controls, it is also
possible to apply
textures to parts of
surfaces as well as an
entire surface.
 Tiling allows pattern to
be repeated, much like
tiles on a floor.

11. Bump Mapping
 Bump maps simulate the
roughness of surfaces even
though the surfaces are
perfectly flat.
 Bump maps make an object
appear to have a bumpy or
irregular surface. This is
possible because of higher
areas are light and lower
areas are dark.
 Surface roughness might
include the unevenness of a
brick surface, the weave of a
fabric, or the bumpiness of an
orange.

12. Bump Mapping
 The process of creating artificial roughness takes
less computing power than actually dividing the
surface into large numbers of polygons and
moving the vertices of those polygons up or
down to create a real roughness.
 Settings allow the user to determining the height
and depth of bumps.
 Bump maps can be produced by photographing
surfaces, scanning images and actual materials,
or by using software programs to draw patterns
in grayscale.

13. Lighting
 3D programs have
some type of default
lighting, which can be
changed to create a
more realistic
appearance.
 There are several
common types of CG
(computer graphics)
lights.

14. The End