Render no lights

[Anonymous]

Dear everybody, 

I have searched a while some posts that more or less have the same problem, but I haven't achieved to solve my problem. I am pretty new with Revit, and I have learned to work with it thought tutorials.

The problem that I have is that when I am doing a render, the light does not turn on. As you can see in the images, I change the lighting option to interior - artificial light but nothing happens. I have two different lights, because I was trying to see if there was a family problem, but i tried with other ones and the result is the same.

I didn't know anything about engines (until I started to read posts), but I guess that I should still be able to create a render with the lights on.

Thank you so much for your time in advance. 

Sincerely, 

[loboarch]

The lighting family itself has to have a light source defined to it. The sample content that ships with Revit has light sources, but the lights i am seeing don't look like sample content so that might be the issue.

The other thing is doing a render in a high contrast situation like this (interior artificial and exterior sunlight at mid day) is sometimes difficult. The exposure ends up getting set for the way brighter sunlight so the light from the artificial lights is not even noticed.

You can test for both of these things by trying the same render at night time using artificial only. That will tell you if the lighting families have light sources in them. If they do you can start messing with settings & exposures to get the lighting effect you want. if they don't, you need to modify the families to have light sources first to have any results.

[Anonymous]

I have checked the family and it seems correct. It has the Light Source, and I have try to render it with just with the interior artificial light and the image is all black.  

So I guess that I might have another thing wrong. 

I have checked also the artificial lights settings to check that both lights are turned on. So I don't know what else to check.

[L.Maas]

Possibly the light source is inside one or more (non-transparent) objects, so no light coming out.

Check that your light source is not enclosed. This can happen in the project (e.g light inside the ceiling) or inside the lighting family.

[ToanDN]

Make sure the light source is not covered by the ceiling.

[Anonymous]

Its not covered by the ceiling, so I guess that might be a family problem. I don't know. I tried to select the parts that might block the light but all the object is just one block, so I can not select the materials of the elements.

I don't know.

[L.Maas]

Upload the family and we can have a look

[Anonymous]

Now I am pretty sure that the problem is the family. I have downloaded another family light from other webside and I have light. The problem is that I don't like the new lights. 

Can you check it please, and tell me what is wrong, for the next time I face this problem.

Thank you.

[rudi.roux]

Hi @Anonymous, 

When you say that you made sure that the lights are turned on, where you referring to the dimming of the lights in the render dialogue box? Are they set to 1 (100%) ? 

Apart from the light source, it might be a problem with the IES file used in the Family. Or, as already mentioned the materials of the family itself which might cause that no light renders through the material/family. The best thing would be to upload the family so that we could have a look at it. 

Below are three links which you might want to bookmark regarding Rendering and Lighting within Revit:

LINK ONE (Referring to IES Files)

LINK TWO (Light Source & Dimming)

LINK THREE (Self-Illuminating Materials)

I hope this helps! 

[loboarch]

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@Anonymous wrote:

Now I am pretty sure that the problem is the family. I have downloaded another family light from other webside and I have light. The problem is that I don't like the new lights. 

Can you check it please, and tell me what is wrong, for the next time I face this problem.

Thank you.

---

The problem is the families. The light geometry is made from an imported SAT file and there is no way to assign different material to the various parts of the lights. The light source is "inside" of this geometry, so no light is getting out. Like if you put a lightbulb inside of a shoe box and closed the lid. Looking at the recessed lighting fixture in fact, the light source is positioned up inside the control box that is in the ceiling rather than positioned in the fixture itself. Where ever these came from, the person making them was not 100% aware of how lighting in Revit works.

You edit the family and move the light source outside of the element and it would at least render light, but I am going to not recommend that simply because the light fixture itself is still going to look bad. Since the geometry come from an imported file you can't assign any materials to it. It will just be one big blob. I am sure those fixtures are nice in real life and are not made from one material.  The fixtures should be remade as proper Revit geometry with material parameters etc...

[rudi.roux · Accepted solution]

Hi @Anonymous, 

As expected, no IES file present and the light source settings within the family is set to use IES data. (IES = Photometric Data).

Change you family light source settings as indicated below. (Highlighted in Blue). 

Also, just set the Coefficient of Utilization to 1 in your Properties Pallet. 

Result: (It's a bit dark, but I loaded the two families into a project, only edited one, the suspended fitting, which is now working. 

I hope this helps! 

[loboarch · Accepted solution]

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@Anonymous wrote:

Hi @Anonymous, 

As expected, no IES file present and the light source settings within the family is set to use IES data. (IES = Photometric Data).

_____________________________________________________________________________________________________________

Light will still render without an IES file. Assuming you have the light source set that way. In these files they are expecting an IES file as well, but you can easily change that to be generic.

The main problem here is the fact the light source is "inside" of the geometry of the light fixture and there is no way to assign a material that would transmit light through it.

[rudi.roux]

I agree, @loboarch.

@Anonymous would be able to render with the settings which I provided, but it would not be accurate.

The best way forward would be to properly model the geometry and assign materials as needed, then also getting the light specifications / IES files from the supplier of the fitting and adding it to the family etc. 

Nonetheless, good luck with the project @Anonymous and I hope the input in this thread resulted in some valuable insights. 

[Anonymous]

Thank you so much for your help both of you. It has been really helpful both messages. 

May I take advantage of this post and ask you another thing?. Since I have written the first post, I have been looking for light families and how to modify them. However I am missing one thing. How do I change the focus of the light. In the pic, the light focus is one dot, however I would like to make like all the surface of the light as a focus. 

I don't know if I express myself right. 

So in the render (Luces.jpg) the light appears from one point, and I would like that I could see that the light appears from the area, more or less as I see in (light.jpg).  It doesn't matter If I change the shape of the light source, it appears the same focus.

Thanks

[loboarch]

With the generic shapes for lighting you can't really "focus" them. If you use the generic conical shape, you can somewhat focus it with the light source definition.

If you use an IES file, that will "focus" the light source based on the properties in the IES file. 

[Anonymous]

I see that I have not express my question right.

The focus of the light is one dot, but I would like to have all the area (marked in red) which should be the focus of the light.

sorry for the child draw 😛 

[loboarch]

No way to control that. the "emitter" is always focused at a point in a conical lighting element. You would have to position the emitter and control the "throw" of the light so it was filling the whole ring in you image, or use an IES file. An IES file I think will change the emitter shape (or at least be more accurate.)