Hi Lucas,

Thanks for this, I think you've identified where the problem lies!

The lines

  MTransPoint (Light->Axis1,     Light->Axis1,     Trans);
  MTransPoint (Light->Axis2,     Light->Axis2,     Trans);

should deal with the area_light axes, but I think that they should use the
MTransDirection() function as the spotlight direction item does and not the
MTransPoint() function. I think that these functions differ in that
MTransPoint() incorporates a translate where MTransDirection() does not.

To check this I replaced the 'translate <0,2,0>' in my test code with

      matrix < 0, 0, 0,
               0, 0, 0,
               0, 0, 0,
               0, 2, 0>

and now the code produces identical, incorrect results whether or not a
transform{} block is used!

I think that this needs to be reported as a Bug in the core v3.6 code. I'm
not sure whether it has been carried over to v3.7 as that's timed out on my
PC.

Well, problem solved I think. Thanks those who have thought about this. Can
anyone think of a work around or is it a show-stopper for what I was trying
to achieve?

Mike Andrews.

Lukas Winter <web### [at] removeitgeloeschtnet> wrote:
> > Can anyone tell me where in the source code a light_source actually
> > applies a transform block? I tried following through from 'parse.cpp'
> > where
[snip]
> Take a look at point.cpp. It seems that Transform_Light_Source() actually
> does nothing special with area lights. Only Translate_Light_Source() does
> not call Transform_Light_Source() (scale and rotate do), but does it
> itself. I don't know how the area light sample points are stored exactly,
> but that may be the cause.

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