[section]Manual Update Appendix: Environment Maps
This rendering technique uses texture
mapping to mimic a mirroring surface. From a carefully choosen location,
six images are rendered, each image representing the view from a side of
These images can then be used as a 'look
up table' for the reflections of the environment.
The usage of a cubical environment map
allows the freedom to position the camera at any location in the environment,
without the need to recalculate the map.
An environment map renders as if it where
an Image texture in Blender. Environment map textures thus have a good
filtering, use mipmapping and have all the antialising features of Image
In most cases an environment map is used
to add the 'feeling' of reflection, it can be highly filtered (for metalic
unsharp reflections) and be re-used at Materials of other Objects without
annoying visual errors.
By default, the faces of all Objects that
define the location of an environment map are not rendered in environment
Examples of the usage of environment maps
are in the tutorfile: ftp:/ftp.blender.nl/pub/tutor_1.6.tgz
[subsection]The EnvMap buttons
Blender allows three types of environment maps:
The map is only calculated once during an animation or after loading a
The map is calculated each time a rendering takes
place. This means moving Objects are displayed correctly in mirroring
When saved as an image file, environment
maps can be loaded from disk. This option allows the fastest rendering
with environment maps.
[point]Free Data (But)
This action releases all images associated
with the environment map. This is how you force a recalculation when using
a Static map.
[point]Save EnvMap (But)
You can save an environment map as an
image file, in the format indicated in the DisplayButtons (F10).
These buttons are drawn when the environment
map type is "Load". The environment map image then is a regular Image block
in the Blender structure.
[point]Load Image (But)
The (largest) adjacent window becomes
an ImageSelectWindow. Specify here what file to read in as environment
This small button does the same thing,
but now gives a FileSelect.
You can select a previously loaded map
from the list provided. EnvMap Images can be reused without taking up extra
[point]File Name (TextBut)
Enter an image file name here, to load as an environment map.
Indicates the number of users for the Image.
Force the Image file to be read again.
Fill in the name of an Object that defines
the center and rotation of the environment map. This can be any Object
in the current Scene.
With this value you can adjust the sharpness
or blurriness of the reflection.
[point]Clipsta, ClipEnd (NumBut)
These values define the clipping boundaries
when rendring the environment map images.
The resolution in pixels of the environment
[point]Don't render layer
Indicate with this option that faces
that exist in a specific layer are NOT rendered in the environment map.