OTOY Forums

By the way, here are some of the renders form my Revit to 3ds Max conversion process

It's improving well. I can't wait till I get the lighting working 100% Very happy with Octane despite the bugs and imperfections. These are 15-20 minute renders.

For reference, this render would look a lot difference if it had proper light areas.

The orange shows that the light is emanating from the middle of the fixture, but iff it was emitting as a linear light, we would see a lot more light in the red areas, especially the corner where both lights meet and the bottom and extremities of the furniture.

Does't the aliasing at the edges of the bright fixtures bother you?

When I render vehicle headlights in a night scene, the aliasing between the bright headlight and the dark surrounding is awful. It's a major shortcoming in Octane, along with not having spotlights.

It could be improved, there must be a way around it? No, I was not particularly bothered, but I think there is room for improvement with the self illuminating materials.

Right now, I am mostly concerned about creating a pipeline that transforms our Revit model efficiently into Octane file while harvesting all the cameras, lights and materials. Unfortunately, the Revit plugin for Revit is not functional enough to be useful.

I have two comments regarding the lights. Right now, there are made of two component: a lit surface material on the lens part of the light fixture and a n actual "light" component. The material glows but does not emit ant light in the scene (not visible).
1-I'd like to get the glow of the lens from the light itself rather than an emissive materiel on the light fixture, that way it could acquire appropriate emissive power and color temperature
2-I'd also like to get a little bit of glow as a post-effect, I haven't tested yet

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Technically there are spotlights since it supports IES files, you just need to know where to look. You could probably use a "narrow PAR 38" or even a theatrical light fixture IES file to simulate a car light. If you really want you can use Lighting Analyst photometric toolbox to craft your own IES file. I would imagine people have found a way around this by now?

narrow PAR 38
http://www.usa.lighting.philips.com/pro ... /par38-led

Theatre light fixture IES files
https://www.etcconnect.com/Products/Lig ... photometry

Lighting Analyst Photometric Toolbox
https://lightinganalysts.com/software-p ... /overview/

Hi guys,
as SamuelAB said:
viewtopic.php?f=27&t=60648&p=310376&hilit=+bulb#p310376
Regards
Paride

SamuelAB wrote:It could be improved, there must be a way around it? No, I was not particularly bothered, but I think there is room for improvement with the self illuminating materials.

Right now, I am mostly concerned about creating a pipeline that transforms our Revit model efficiently into Octane file while harvesting all the cameras, lights and materials. Unfortunately, the Revit plugin for Revit is not functional enough to be useful.

I have two comments regarding the lights. Right now, there are made of two component: a lit surface material on the lens part of the light fixture and a n actual "light" component. The material glows but does not emit ant light in the scene (not visible).
1-I'd like to get the glow of the lens from the light itself rather than an emissive materiel on the light fixture, that way it could acquire appropriate emissive power and color temperature
2-I'd also like to get a little bit of glow as a post-effect, I haven't tested yet

---

Technically there are spotlights since it supports IES files, you just need to know where to look. You could probably use a "narrow PAR 38" or even a theatrical light fixture IES file to simulate a car light. If you really want you can use Lighting Analyst photometric toolbox to craft your own IES file. I would imagine people have found a way around this by now?

narrow PAR 38
http://www.usa.lighting.philips.com/pro ... /par38-led

Theatre light fixture IES files
https://www.etcconnect.com/Products/Lig ... photometry

Lighting Analyst Photometric Toolbox
https://lightinganalysts.com/software-p ... /overview/

The only solution to the aliasing is to increase render size and samples(these aliased areas are very noisy when animated, not an issue for stills), and down-sample the image. Animation render times become impractical very quickly in that scenario.

I've tried IES without much luck. I was never able to find one that approximates a car light. Car lights are designed to throw light a long ways, unlike typical architectural lighting. In order to get decent throw in the distance, you have to crank up the output and you end up with an unnatural amount of spill close to the light which blows the scene out.

As far as I'm aware, IES is really only something that's used in architecture. For that reason, it's not really a viable substitue for general purpose and CG applications.

I would use Photometric viewer to make a shape like this: It can surely be done.

Actually looking at pictures of headlights online, it seems like a tight beam, nothing fancy, Its just the way and angle it is aiming at the street that matter.
If you just look at the photos of most of these car lights and use a PAR38 IES file, you can recreate it pretty easily I'm sure.

SamuelAB wrote:I would use Photometric viewer to make a shape like this:

The attachment Car.jpg is no longer available

It can surely be done.

Actually looking at pictures of headlights online, it seems like a tight beam, nothing fancy, Its just the way and angle it is aiming at the street that matter.

The attachment Car2.jpg is no longer available

If you just look at the photos of most of these car lights and use a PAR38 IES file, you can recreate it pretty easily I'm sure.

Here is a test with a PAR38. This is with the power set to the maximum of 100000, and exposure set at 20. You can see there is no distance throw, as you'd get from a headlight, and most of the light is right by the front of the car. Maybe I'm doing something wrong, but that's the same result I get with all the various IES lights I've tested in the past. Also shown is the custom spotlight I created with an Octane material, and that process is completely ridiculous, un intuitive and undocumented.

What you have rendered is actually pretty good. Did you use particular pictures to inspire yourself when trying to recreate the car head light? I had a look for both headlights and light shapes of car head lights see from above at night, to understand the shape to be expected and the underlying lighting strategy, if any.

Have you looked at the shape of the PAR 38 projection? There are three usual shapes, narrow, medium and wide/large beam. Each company will have a slightly different IS shape depending on the optics.

I made a graphic example of reverse engineering light with an IES. Have a look at the result and then ask yourself what kind of light distribution you would need. It helps if you are used to looking at lighting fixture specification sheets and know what kind of distribution will give you what kind of results.
So, if you want to get fancy, grab an IES editor and play with this kind of shape. You are lucky in that this kind of circular reflector based light is easier to edit that a complex 3D shape. It's a curve that is revolved 360 degrees, which most crude IES editors support.

I think this is a free IES editor, it's a bit vague.
https://www.dial.de/en/dialux/ldt-editor/

This one is €60
https://www.real-ies.com/

This one is probably the most used, they have a free trial
https://lightinganalysts.com/software-p ... /overview/

You can't say you've tried everything until you used a tool to edit IES files, haha

You could also play with overlapped IES file and different combinations of power, angles and light distributions (narrow/medium/wide)

Also, look at pictures of cr head lights, they usually have complementary decorative reflection pieces and useless lights. There's also a combination of high and low lights. Thuink about it, there's probably thousands of people whose job is to design car head lights, haha. They also use a lot lensing strategies, I am guessing mostly for aesthetics.

Hi @Paride,

Do you think this is something that can be solved by Octane with time?

Please let me know if you have questions about the file.

Thank you