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Custom Lights, ies files


Benson Shaw

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Just made my 1st custom lights, working in v2015 Designer

Set up"

4 little stages, ground plane 3d poly floor, xz plane 3d poly "screen".

1 light focused on center of "screen"

1st light is vwx light object, 40°/20°

Others are custom lights with lumenpulse.com ies files supposedly with successively narrower beam spread.

But beams are all figure 8 shape. That can't be correct beam shape???

Same figure 8 shape in v 2016 SP2

And, the beams get wider instead of narrower in each iteration.

Bad file from mfg? Improper interpretation by vwx?

Any experience with the ies distribution files? Comment?

Also, when render in Realistic Exterior Night (fast or final) if text present on ground plane the spots appear. If no text then 3d poly renders as expected. There was an earlier post about this problem. Didn't look for it yet.

EDIT: These spots are fixed in v2016 SP2 (maybe in SP0 and SP1, as well).

-B

ubbthreads.php?ubb=download&Number=13540&filename=Lights-WireFrame.png

ubbthreads.php?ubb=download&Number=13541&filename=Lights-RealExtNight%20Fast.png

Edited by Benson Shaw
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Benson- something is definetly not right. I've used .IES files without much trouble, but I haven't tried in Vw2016 yet.

On the Mac there is not an .IES file viewer that I know of, but the following website will allow you to open and view the profiles for those Lumenpulse .IES files. That way you can determine whether or not you have bad .IES distribution files:

Photometric Viewer : Visual-3d.com

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Thanks, Tim

Here are a couple charts from the Visual-3d.com pages for the LumenPulse 40° flood light. 1st one shows a tear drop shape. Looks like it is mirrored and duplicated in my vwx custom light. The candela chart shows a round distribution.

Should one of these describe the 3d shape and spread?

I doubt that this light fixture would project a tear drop shape beam or a double tear drop without optional optics. For my vwx model, probably better to assume generic conical beam than the dbl tear drop with zero lumens at the focus.

Additional comment welcome.

-B

ubbthreads.php?ubb=download&Number=13544&filename=ies.png

ubbthreads.php?ubb=download&Number=13545&filename=IsoCandela.png

Edited by Benson Shaw
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@Benson: that's a very thorough explanation of what Vw should display with Custom .IES light fixtures. As you made the Visual-3D test settings match your Vw2016 test settings (light fixture setback 5' away from a 5' square surface), I see no reason why Vw does not display the same results. The problem appears not to be with the .IES distribution file.

Reading back through your OP - just to be clear - both Vw2015 & Vw2016 give the same incorrect 'figure 8' light results?

I know your test file is easy to replicate, but could you post your Vw test file along with a separate .ZIP file containing the .IES files?

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Reading back through your OP - just to be clear - both Vw2015 & Vw2016 give the same incorrect 'figure 8' light results?

Yes, same figure 8 projection in vwx v2015 and v2016. It looks like Vectorworks is picking up a different chart form the ies data. A good compare would be if other lighting software makes a different 3d projection. I think that Vis3D "model" is 2d interpretation of 3d data (but not sure).

Here is vwx (v2016) and ies (as a zip).

I sent the files as question to Tech support, too.

Thanks for looking at this. I am totally unqualified.

-B

Edited by Benson Shaw
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  • 2 weeks later...
This seems to suggest that the ies file provided by LumenPulse has something amiss.

I will try to contact them.

-B

Benson: I figured out why those .IES files from Lumenpulse were not rendering correctly. There's nothing wrong with the .IES files from Lumenpulse, it's just that Vectorworks (and Cinema 4D) cannot interpret them correctly.

LED-based lighting products aka Solid State Lighting (SSL) are measured with absolute photometric testing, whereas typical non-SSL fixtures are measured with relative photometric testing.

If you open up one of those Lumenpulse .IES files with a text editor application, you'll see that the second number in the first line (after the [commented header] notes) is a -1. The .IES files for non-SSL fixtures will have the rated lumens for the fixture listed here, not a negative number.

[EDITED : this potential workaround was found in a Revit forum and may not work exactly as described in Vw]

Until Vectorworks has the ability to read absolute .IES files, a temporary potential workaround is to edit the .IES file and replace the -1 with the rated lumens, which you found by uploading the .IES file to Photometric Viewer : Visual-3d.com and it's listed under 'Total Luminaire Lumens'.

ubbthreads.php?ubb=download&Number=13694&filename=ies_annotated.png

Doing this would allow you to 'see' the relative light distribution web but these results would be technically invalid. However, since Vectorworks is not a photometric lighting analysis tool, it might work well enough to give you a general sense of how the light would look.

Reference links:

Absolute Photometry, SSL & AGi32 : AGi32.com

The IES Photometric File Format, Scott J. Brown : Penn State University

Edited by rDesign
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Thanks Dave, that saves me having to create a wish list item for it!

As LED-based light fixtures are becoming much more commonplace this limitation is only going to become an even bigger issue.

Revit's internal rendering engine currently also has the same inability to read absolute .IES files, so there is a window of opportunity to get out in front of the competition. :)

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Whoa - Tim, thanks for continued inspection and response!!!

I opened the ies distribution file in Text Wrangler, changed that -1 to 640 and saved the file.

Then I opened my test file and reloaded the modified ies distribution. Light pattern renders that same figure 8.

Did your test result in roundish projection?

Is there some other value needing adjustment?

-B

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Hmmm. :( Unfortunately no, I didn't try to reload the modified IES file back into Vw; That would have been the obvious thing to do!

That method of 'replacing the -1 with the lumens' was a suggested solution I found on a Revit forum; There may be something else about these absolute IES files that Vw (and CineRender) cannot read correctly. What that might be, I have no idea.

So if modifying that -1 doesn't work for Vw, then I'm all out of suggestions until Maxon works it out on their end.

When I get a chance I'll try it myself with these Lumenpulse and other LED-based .IES files. I'll post my results back here, but I'm guessing that I'll get the same results as you.

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At this point I'm just changing values in the ies file. Y'know, poking and pulling to see what happens.

Scott J Brown's ies format paper is very informative.

Tried a few other values for position of the -1 in the metadata line with subsequent save and reload to custom light. Tried 1, 0, -640. None caused perceptible difference in the Final RW rendering of the projected light pattern.

Trying elimination of one or several of the V data sets for various H angles. Worst scenario is vwx crash. I will report if I come up with anything.

-B

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Well - I spent a bit of time with a bunch of different absolute (-1) .IES files, and some of them rendered with the same incorrect 'figure-eight', while others rendered correctly. I didn't even bother with replacing the -1 with the fixture lumens, as sometimes they still worked with the -1 in place.

So, I stand corrected and no longer think it's conclusive that it's the absolute .IES files that are the problem. But when I did get the 'figure-eight', it was with an LED-based light fixture. There has to be something about the way some LED-based .IES files (like the Lumenpulse ones) are either formatted or created.

Sorry if I got anyone's hopes up. :(

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  • 5 years later...

I realise this is probably a bit too late to be useful, but I was trying to work with the LP .ies files and noticed that the ones in the BIM download catalog (.bim.ies) are slightly different than the ones mentioned here.  For one thing, the testlab is Intertek, not LumenPulse.  And also, the headers are properly formatted, no -1 in play, just the normal intensity value.

 

Anyway if it still matters to the few trying to incorporate LumenPulse into your work, give a look at the Tecnical Files - Revit (BIM) section

 

 

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  • 1 year later...

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