It appears that the place were the uv_mapping code is placed in the latest 
version of Poseray generates a faulty rendering of transparant materials.

In the present version, uv_mapping is coded in the xxxx_POV_mat.inc file as 
follows:

#declare MyTex_=
material{
texture{ pigment{uv_mapping p_map1}
        finish{specular 0 roughness 0.00286312 ambient rgb <0.00,0.00,0.00> 
diffuse 0.8   reflection{0 } conserve_energy}}
}

or, in the case of a transparancy map:

#declare MyTex__opaque=
texture{ pigment{uv_mapping p_map1}
        normal{uv_mapping p_map2 bump_size -6.192}
        finish{specular 0 roughness 0.00286312 ambient rgb <0.00,0.00,0.00> 
diffuse 0.8   reflection{0 } conserve_energy}}
#declare MyTex_=
material{
texture{  pigment_pattern{uv_mapping p_map3}
texture_map{[0 pigment{Clear}]
            [1 MyTex__opaque]
           }}
}

In particular the alpha channel of the first example does *not* work for the 
shadow casting. In order for this to work in all cases, the code should be 
written as in a previous version of Poseray, i.e. the uv_mapping code is 
written in the xxx_POV_geom.inc file and *not* in the xxx_POV_mat.inc one. 
As follows:

//Model assembly from the meshes
#declare My_Figure_=
union {
object{My_Figure_1_  uv_mapping material{MyTex_1_}}
object{My_Figure_2_  uv_mapping material{MyTex_2_}}
etc...
}

This construction provides a correct render of the transparancy of the alpha 
channel.

Thomas

Post a reply to this message