YafaRay Plug-in

[oort]

I am still hunting for what controls the direction (x,y,z) photons are emitted. I am also playing with some of the settings and have noted the following:
In the Ambient Light/HDRI "Cast Shadows" needs to be enabled.

In the light portal Material settings for Object Parameters "Photon Only" needs to be enabled. Setting the "Samples" setting in the light portal to a value of between 128 to 480 removes graininess without a big impact on render time.

Here is what the plug-in code is so far. The change to object type to make the light portal invisible is in bold.

lightportal ->
println(F," "),
println(F, "<light name=\"~s\">",[NameStr]),
println(F, "<type sval=\"bgPortalLight\"/>"),
println(F, "<power fval=\"~.10f\"/>",[Lightportal_Power]),
println(F, "<samples ival=\"~w\"/>",[Lightportal_Samples]),
println(F, "<object ival= \"~w\"/>",[Id]),
println(F, "<with_diffuse bval=\"~s\"/>",[Lightportal_Diffusephotons]),
println(F, "<with_caustic bval=\"~s\"/>",[Lightportal_Causticphotons]),
println(F, "<photon_only bval=\"~s\"/>",[Lightportal_Photon_Only]),
println(F, "</light>"),
println(F, "<mesh id=\"~w\" vertices=\"~w\" faces=\"~w\" has_uv=\"~s\" type=\"256\">",[Id,length(Vs),length(Fs),HasUV]),
println(F," ")

end,

export_vertices(F, Vs),

I will add an image of an example render to this post later today.
Edit: I edited this post to correct the information due to knowledge gained from further testing.

oort