Trying to accurately model a linear LED fixture.

[mcobb]

I'm trying to model a linear LED fixture under a bookshelf. Our lighting designer knows that the IES file for this fixture is vital to avoiding a hotspot at the wall when the fixture is installed just an inch or so off the wall face. I was really pleased to see that Qtrans provided an IES file for this fixture (see attached). I was disappointed to see that when I inserted this file into the family it was just a point source. As you can see from the link (https://q-tran.com/product/sw24-4-0/) the fixture is a linear type fixture.  Any help modelling this would be greatly appreciated.

Mike

[barthbradley]

Results using SW24-4.0_DRY_40.ies.  

Play with your Exposure Controls post-Rendering and see if that helps.  

[mcobb]

Thank you barthbradley.  I guess the thing that has me stumped is the hot spot I'm seeing at the middle of the fixture on both our renders.  Shouldn't a linear LED emit light more uniformly along its length than this?  Am I missing something? Hope you're well.

Mike

[barthbradley]

Even the Light Source Definition using the "Line" with "Photometric Web" shows it this way (e.g. light emitting from point).  

[mcobb]

Kinda weird.  Seems like it can't be entirely correct, right?

[Anonymous]

Since Revit updated their rendering engine 1-2-3 years ago, area lights are no longer rendered accurately.

If you export this to 3ds max and render with a proper render engine (Iray, corona, etc), it will show as a proper area light.

Basically Revit`s new render engine is faster but quite bad for area lights.

[Anonymous]

I'm experiencing the same issue in Revit 2021. Even though the Emit Shape size is defined as a long thing rectangle spanning the length of the luminaire, it renders as a point source.