You should just use 0,0 - 1,1 as coordinates. 0,0 is top-left corner of the image and 1,1 is bottom-right corner. So if you use that mapping the texture will fit perfectly on the plane.
Greetings, On Dec 1, 2007 3:15 AM, Patrick Ye <[EMAIL PROTECTED]> wrote: > Hi guys, > > I have another noob question and it's about the UV coordinates for a > plane. I'm trying to write some code that can take generate a genmesh > file for a plane. > > Let's say that the plane is centered at the origin and only on the XY > plane, and *half* of the width and height of this plane is w and h > respectively, and > the four corners of the plane are as follows: > > (-w, -h, 0) > (-w, h, 0) > (w, -h, 0) > (w, -h, 0) > > I read on the wikipedia that the calculation of the UV coordinates is > given by the following formula: > > U = x/sqrt(x*x + y*y + z*z) > V = y/sqrt(x*x + y*y + z*z) > > I followed that calculation for each of the coordinates of the plane, > but the image only gets mapped > partially. I used blender3D's uv editor to generate something similar, > and the blender's UV coordinates > are vastly different from mine. So, what am I doing wrong? > > Here is the genmesh file I created: > > <meshfact> > <plugin>crystalspace.mesh.loader.factory.genmesh</plugin> > <params> > <material>map.png</material> > <v x="-59.35" y="-33.75" z="0" > u="-0.869277778378" v="-0.494323926205" /> > <v x="-59.35" y="33.75" z="0" > u="-0.869277778378" v="0.494323926205" /> > <v x="59.35" y="33.75" z="0" > u="0.869277778378" v="0.494323926205" /> > <v x="59.35" y="-33.75" z="0" > u="0.869277778378" v="-0.494323926205" /> > <t v1="0" v2="1" v3="2" /> > <t v1="2" v2="3" v3="0" /> > <autonormals /> > </params> > </meshfact> > > The image map.png has the same aspect ratio as the plane I'm trying to create. > > Thanks a lot. > > Patrick > > ------------------------------------------------------------------------- > SF.Net email is sponsored by: The Future of Linux Business White Paper > from Novell. From the desktop to the data center, Linux is going > mainstream. Let it simplify your IT future. > http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 > _______________________________________________ > Crystal-main mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/crystal-main > Unsubscribe: mailto:[EMAIL PROTECTED] > -- Project Manager of Crystal Space (http://www.crystalspace3d.org) and CEL (http://cel.crystalspace3d.org) Support Crystal Space. Donate at https://sourceforge.net/donate/index.php?group_id=649 ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ Crystal-main mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/crystal-main Unsubscribe: mailto:[EMAIL PROTECTED]
