🚀 go-pugleaf

>>Wolf3d is perspective mapping.  Ultima Underworld is a combination of
>>perspective mapping and texture mapping, depending on the situation.
>>Josh
> 
> In Wolfenstein 3d, all objects are texture mapped squares with normals
> perpendicular to the vertical.  Some people refer to the viewing
> of rectangular images with view direction not parallel to the
> surface normal as perspective mapping.

My point.

> I believe that the term 'perspective mapping' originated from
> paint programs like delux paint which allow you to take an image
> and map it onto a plane viewed from any angle.  It really should not
> be used out of that context.

The term perspective mapping didn't necessarily originate from paint
programs.  A fellow programmer on the C64, years ago, referred to a
certain process in his program as perspective mapping.  Wolf3d is
probably best considered perspective mapping.  As mentioned in a previous
message, perspective mapping is a subset of texture mapping.  

> Texture mapping is the process of making an object look more realistic
> by filling it with an image rather than flat colour.  Just another
> step along the route from wire frame to solid 3d to....

Texture mapping covers a wide range of subjects.  For instance, while I
can't deem this as true, I've heard the term texture mapping used to 
describe the mapping of a 2d image to a sphere.  Without getting complicated,
texture mapping can refer to the mapping of any 2d image to a 3d image. 
Perspective mapping lightens this subject up a bit by saying "mapping
a 2d image to a 3d plane...not a combination of 3d planes."

Josh