Twilight settings for interior lighting

I am so frustrated. I change one thing at a time, and render each time, to try to see which settings I need to change to achieve some reasonably nice looking results.

I don’t get it. My model just keeps looking worse and worse. What am I doing wrong???

I have attached my model, and screen shots of my environment settings and the light settings for the one light I have configured in the room.


Can somebody explain to me why there is “Brightness” and “Sun strength”??? That sounds like two of the same dang thing. I tried decreasing Sun strength and the room got crazy brighter, but when I put the setting back where it was, it stayed the same.


Link to my model:

What it looks like rendered:

After tweaking the settings:


Before I start shouting things out is your spherical sky an HDRI or just a simple image file ? If it’s an HDRI you need to un-tick “Sun Enabled”. If it’s just a spherical jpg image I’d start by lowering “Sun Strength” I do a lot of exterior renders with Sun Strength at 3.5 or 4. You just need to experiment with the Brightness and Sun Strength settings until you see the result your looking for. Where do you have the point light placed? One last thing … it’s real hard to figure out what’s going on without the model to look at.

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Looks like some of your model stopped casting shadows. Could be a sketchup thing or a twilight material thing. I’d look into that.

I would look at it in monochrome mode again as some of the glass in the windows is reversed. It also looks like you have sunlight coming in through the ceiling. I would turn down the intensity of the interior light too.
Much like a camera, the sun strength and brightness/exposure, while related are different. The brightness is like altering the camera exposure affecting the whole image, whereas the sun strength (or other light strength) will be affecting that element only, even though it will have an affect on brightness.

Didn’t realize one of your pictures was a link to the model, sorry. Downloaded it for a quick look. First most obvious was your point light is scaled up to fill the entire room… not good. Think the biggest problem is the model itself. Stuff renders better if things are physically accurate, examples are walls and ceiling having real world thickness. Can’t make much sense how you have a lot of your material templates set up either. Going to look a little deeper at it.

I’m not in Twightlight but principles are the same. If you want ambient light in the room I would use a soft area light. Using an omni light in the middle of the room is like hanging a bright bare bulb in space and it can produce hard shadows and light everywhere.

The first one is using an HDRI and the second just sunlight.

The 3rd one is just a detail but you can see the sink flange when it renders shows it to be a thin edge, so it should have some thickness - or rather a face that comes down to the counter.

I also took the glass out of the windows as the bottom sash appears to be open and may not be worth the time?

2d shows no overhead can lights light as a room fill but is using the sun on the wall through the door as a bounce fill.

Its always more convincing to use light sources from their expected positon, sometimes when we cheat it it doesnt quite look right even though it may be hard to put your finger on it.



Took a good look at your model. It took a considerable amount of fixing to get a good base for rendering in Twilight. First thing if you are going to use an HDRI to light your model do not use the sun at the same time. Testing with an HDRI and with just the sun I was still getting huge amount of light leaks through the ceiling. It took redrawing your model with actual thickness to the walls and ceiling to get rid of the leaks. Also remodeled the windows and doors so

they only had single planes for the glass. There was multiple different glass materials also. Deleted all but one and used that on all the glass. Used the “Architectural Glass > Common” template. There was a lot of objects that had been painted without clicking the group/ component open before painting. Fixed those as that can cause issues with rendering. Got the model and materials squared away and ran a quick render on Easy 9 setting. Unfortunately had to substitute a few textures as I lost some when repairing the model. Posting a pic of the quick test . Render was lit with an HDRI spherical sky and one point light positioned behind the camera. Not a finished render by any means but should give you an idea of what can be done in Twilight. Really suggest you spend some time on Twilights forum, lots of good tutorials and tips to be had.


Thank you for all the tips…

the bottom sash appears to be open and may not be worth the time?

I forgot to mention, the windows are interactive, and can be closed, but the model was saved with them in the open position. They were downloaded from the 3D warehouse, created by one of the big manufacturers, Pella or one of those. Regardless, I’ll take your word for what needs to be done with them.

2d shows no overhead can lights light as a room fill but is using the sun on the wall through the door as a bounce fill.

I did have light fixtures in the ceiling where all the holes are - in fact, I had this model completed with cabinets, appliances, and everything, but it was such a ridiculous size, something like over 200MB, so I stripped it back down to the bare minimum in order to get a manageable file size that I can render quickly and not crash my computer while I am learning how to use Twilight.
Also, I tried rendering with just ambient light through the doors and windows, and no matter how much I cranked up the brightness and sun strength, all that happened was a more washed out view out the windows, but it remained super dark inside. That’s why I added a light inside.

Much like a camera

I don’t know the first thing about photography :frowning: I wish I did! Other than very basic things like exposureand maybe aperture, but I can see how that type of knowledge/experience would help understanding Twilight (and probably rendering in general).

is your spherical sky an HDRI or just a simple image file ?

I don’t know, how do you tell the difference? It would have to be spherical, or it wouldn’t work in the “spherical sky” setting, would it not? I tried to upload it to show you but the file is too big apparently. I think it is, the file name starts with HDR, so…

redrawing your model with actual thickness to the walls

I had no idea this was so important. I will make this my top priority as my next step, before adding any more objects to my interior.

single planes for the glass

I’m surprised the manufacturers that created these put the glass in backwards, and multiple panes… although, I guess they are less interested in rendering and more interested in real-world accuracy, probably. I’ll get to work on the windows as well.

Your renders look AMAZING, especially compared to mine! Do you mind sharing the actual settings you used? Would that be possible? :smiley:

Thank you so much for taking the time to troubleshoot. This has really helped me a lot, some basic knowledge to get me going on my own!

Instead of stripping down the model you could put different items on layers - appliances on one layer, furniture on another, etc, then toggle off those layers for a render as the renderer will only deal with items in the scene and not the hidden items in the model.

I think rendering does require a grasp of photography (and texturing) which is a whole other discipline and one that is overlooked. Much like the real world, modeling and building something is one skill set and photographing it another.

Balancing light in a scene is a subtle process, while you have the control to get it dialed in perfectly, I think some imperfections look more natural. For example I feel seeing what’s outside of the windows should look a little over exposed.

Consider that your exposure control ( whether brightness, f-stop or shutter speed) will affect overall brightness of the whole image, if you were to have a light/lamp in the scene that was on a dimmer, by adjusting that slider that light will get brighter or dimmer, more noticeably in its immediate surroundings as as well as affecting the overall scene.

I think if Tuna1957 can share his render setup with you then you could see and adjust from that what it is that makes the lighting work.

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Instead of stripping down the model

LOL, well the part I left out was, I am so new at this, learning is taking place at an exponential pace… :laughing: I had other reasons for stripping down the model. I had to take each different feature, such as a single cabinet, or a countertop, etc., and save it in its own file, purge all excess components and materials, compare it to similar models in the 3D warehouse to see what the file size should be, delete excess random layers that seemed to just appear out of nowhere, until I got all my individual pieces down to the minimum possible sizes.

Only then will I put them back together into a whole room, and continue building my model. Correctly.

I learned that when downloading random items from the 3D warehouse, I really need to pay close attention to what they bring with them! They add all sorts of perhaps-not-necessary materials, components, layers, even hidden geometry sometimes… SURPRISE! :open_mouth:

Also, when trying to get really extra fancy with nice materials like the marble and granite that I downloaded from other websites like, those can add up QUICK. Gotta be more pragmatic with those.

But I hear you about the layers. I do plan on taking that step eventually, and using layers to make my model more organized, I just haven’t gotten around to it yet.

One option for checking on a component’s density is to look in the component’s tray statistics with “expand” checked.
Also if you right click on a component and choose “save as” you are able to save that component out as a separate sketchup file. You can then look in your explorer in a detailed view to see the size of it as a skp.

There are a number of decent models here (rather than 3DWH) and there is a plugin “rubysketch scale tool” which will directly link to the library.

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Thank you! I will check it out!

Easy to tell the difference between an HDRI or plain spherical image, the suffix for the HDRI is .hdr , a plain spherical image is usually a .jpg image file. The difference for rendering is the HDRI will contribute all the lighting information to the render. Thats why you should disable the “sun” in the environment editor. Having single plane glass allows you to use the “Architectural Glass” template. The benefit is that it will render faster than glass modeled with actual thickness that has had the “Glass” template applied to it. One way to keep your model size more manageable is not to use Dynamic Components unless you really need to. “DC’s” can be pretty “heavy” due to the way they have to be modeled. When you import models from the warehouse it’s best not to import them directly into your model. Better to save them to a separate folder and go into them and do whatever cleanup may be needed before using them. It’s time well spent. A lot of times in my experience it can be faster to just model what you need as needed. It’s also good practice! Posting the light set ups that I used for doing the test render. If I can get my “DropBox” account back up and running I’ll post a link for the model.!

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Forgot a couple of things… The environment setting of 1.1 Brightness was for the HDRI I used. You should start with 1.0 Brightness and run quick tests to check how things look. Also rendered my test on Easy 9 , 5 passes.

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Thank you so much!! This helps so much!

Well, the file I used was a .jpg, so it definitely was not a HDRI. Those websites with free materials often don’t show you what file type you are downloading. :frowning: So, you don’t know until after you download a zip file and extract it. What a pain.

I’ll do some more searching for some actual HDRI images.

try here: HDRIs: Outdoor • Poly Haven

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Thank you! :smiley:

Hey I just am getting around to really looking at your model, and now I’m finding out that you are using the pro version of Twilight. I’m using the hobby version, so I don’t have access to the deep editor for materials. Will that make much of a difference?