using looks_like command in pov-ray

[Joscha]

Hi

since a few days I try to figure out how to create a kind of 'light bar' in pov-ray. I mean a for example a 1x4 plate which seems to emit light from its surface like shown in the pov tutorial with the command looks_like.

I started with a smal example:

I used a transparent brick (LDXColor79) and an area light with 4 light in a row placed exactly on the surface of the transparent brick.
What I do not like in the result is that the brick does not seem to emit light. I would like to have just a plain white surface.

Then I changed the colour of the plate to white:


Here I had to move the area light slightly above the surface in order not to get blocked. But this is still not the look I wanted. Therefore pov-ray has the looks-like command.

If I try to use the looks-like command in the light source definition I have to point to an object name, i.e. the name of the brick. I searched the line in the pov-script where the object is defined...

// Author: LDraw
object {
        lg_3710
        matrix <0,0,-25,-25,0,0,0,-25,0,0,0,0>
        LDXSeamMatrix(80, 12, 20, 0, 2, 0)
        matrix <1,0,0,0,1,0,0,0,1,0,-32,0>
        #if (version >= 3.1) material #else texture #end { LDXColor15 }
}

and added:

#declare lightbar =    object {
        lg_3710
        matrix <0,0,-25,-25,0,0,0,-25,0,0,0,0>
        LDXSeamMatrix(80, 12, 20, 0, 2, 0)
        matrix <1,0,0,0,1,0,0,0,1,0,-32,0>
        #if (version >= 3.1) material #else texture #end { LDXColor15 }
    }

The result after this step is already that the plate is missing.


I tried to draw a box with the box command instead, but if I try to declare it to give it a name to be refered to with the looks_like command, the box disappears (like above the lego plate). Just using the light w/o looks_like brings this:

It looks already similar to the resulty I have seen in the pov tutorials applying the looks-like command.

But then my questions are, is there a difference between the above image (looks_like not applied) and an image with the looks_like command applied? And how to use it in the code?

Regards
Joscha