Behaviour of a Photometric Web distribution within a Lighting Fixture Family

[Anonymous]

Photometric Web distributions are typically created to account for the interaction between lamp and luminaire. I want to incorporate this lighting definition into a 'Lighting Fixtures' family, but cannot work out how to stop the model geometry in the family affecting the 'action' of the Photometric Web.

The family In question is a bollard-type with a spherical-type distribution and so the placement of the definition is inside the model. I have managed to get the family to produce a 'lighting' effect, but am worried that the transparent materials and even adjacent model surfaces within the family will affect the way the lighting definition illuminates the surrounding scene. The bollard has internal reflectors that are 'characteristic' of its design, and I do want to display this detail when viewed in all views.

I imagined that it would be as easy as a check box to remove specific model geometries from interfering with lighting calculations. I could not find a way of doing this so am asking if there is a best practice method of ensuring that Photometric Webs work in a realistic manner.

As additional comments for clarity. A Photometric Web definition requires an insertion 'point' but the distribution also represents a light source emitted from a specific volume. Sometimes these volumes are complex and so if model geometry used to represent the appearance of the luminaire, (something the photometric web does not do) shades and/or reflects the action of the photometric web definition, the effect on the scene will be incorrect.

Looking forward to some comments. Thanks.

[barthbradley]

Almost sounds like you are talking Material Transparency.  If so, is the Asset capable of Transparency? Render Appearance. 

[Anonymous]

I imagine material transparency is currently the workaround solution. As an example. If a bollard post has a 20 mm wide light-source ring around the post at the top. Placing the *.ies photometric web at the centre top would mean that the top circular surface of the bollard post casts a shadow onto the ground. I really do not want to have to change the material parameters of the post as this would also affect other instances of the material in other objects. Is there a way of making a material 100% transparent to only the 'light source' object within the family. The *.ies definition already ensures the correct light behaviour (because the bollard as a whole was measured in a goniophotometer and is considered a unified lamp) such that the fall off towards the base of the post is smoothly graduated.

note. Elevation and plan views are not a problem as I can use detail lines to create the object, assuming that LEFT/RIGHT and FRONT/BACK details are symmetrical. 3D views seem to be the challenge...

[barthbradley]

Self Illumination Materials?