Some questions about lights

[marlem2000]

Hi!

I’ve been struggling with lighting for a long time and I have some general questions I haven’t solved yet.

In the “Electrical Service Specification”, what’s the “direction angle” made for? When I modify it, nothing happens on the light or, at least, I can’t notice anything.

In general, when I make the final render in physically based view, the result is too dark, no matter the configuration of the lights. It always looks like being in twilight and it seems lighting is never enough. When this happens I change the exposure to manual and adjust saturation and brightness. Of course, I set the background light too.

Anyway, lighting doesn’t improve a lot. The same way, I adjust sunlight to “use generic sun (mid-day)” but the final result keeps on looking dark. Am I missing something?

 

*Ops! I forgot! Another doubt I have is I can't project general shadows of objects. When I want to do this I just click on "casts shadows" but most of objects on the floor don't show anything. They look like floating and that makes the scene doesn't look realistic.

Edited August 26, 2023 by marlem2000
I forgot

[robdyck]

These are relatively complex problems that often require the plan file to inspect and trouble shoot each issue. There are some methods that are universal, but the same settings do not always produce the same result from one model to another. 

In this case, it would best for you to post a plan file and you should use the 'Backup Entire Plan' tool so that all your materials remain with the plan file.

Once someone has a chance to view your model, they should be able to identify solutions to each problem. This requires examining all camera settings, the construction of your model, all the materials, and light setting for each light source.

[DBCooper]

I always find it best to play with lighting and materials in a simple test plan.  Once the plan has a lot of stuff in it, it gets really hard to tell what effect the settings have by themselves.

 

The light direction controls which way the light is pointing if you were to look at it from the top down.  In the picture below, the light on the left has a -30 degrees angle, the one in the middle is 0, and the one on the right has a +30 degree angle.  The tilt angle is the same for all of them.  All of the boxes are directly in front of the lights but you will notice how the two on the sides are only partially in the light area.  One reason you might not be seeing shadows is if your lights are not pointing where you think they are.

 

I will let others with more knowledge comment about the other questions.  My guess is that they will want you to post a plan to play around with it though.

 

[marlem2000]

2 hours ago, robdyck said:

In this case, it would best for you to post a plan file and you should use the 'Backup Entire Plan' tool so that all your materials remain with the plan file.

Once someone has a chance to view your model, they should be able to identify solutions to each problem. This requires examining all camera settings, the construction of your model, all the materials, and light setting for each light source.

 

 

I understand. The problem is this project has a size of 140 mg compressed in zip. It's a too big file to attach here. Maybe I can share it on Google Drive.

 

1 hour ago, DBCooper said:

All of the boxes are directly in front of the lights but you will notice how the two on the sides are only partially in the light area.  One reason you might not be seeing shadows is if your lights are not pointing where you think they are.

 

I will let others with more knowledge comment about the other questions.  My guess is that they will want you to post a plan to play around with it though.

 

 Yes. I'm seeing this is complex. I still don't understand very well the angle thing; I'll make some tries on an empty project.  I guess I'll have to make a small test with only some symbols. I'm used to play with so many things. 

[robdyck]

20 hours ago, marlem2000 said:

Maybe I can share it on Google Drive.

This would be ideal.

[Kbird1]

Hi M,

 

Have you seen this KB Article on Lighting?  

https://www.chiefarchitect.com/support/article/KB-00777/working-with-lighting.html

 

Some Basic Tips on Lighting I use..........

 

 

At least for Me, CA's default settings are too low by about 50% for a well lit scene so..... 

 

In Rendering Techniques, in Your Template ( or make current plan into a template for future projects)

 

Under Standard

Set your Interior AND Daytime Ambient to 60%              ( I set Night-time to 6% as well)

 

Under PBR

 

Automatic exposure in X15 is usually fine at .35 , but try .4 or even .45 in individual Cameras

 

set the Brightness to 30 ........this is a start point for me and individal Scenes may need as high as 70%

 

I also start my Daytime Backdrop intensity at 700      and set both Cap Live Samples and Denoise when Complete to On .

 

Other Tips

 

Try the Scene with Shadows OFF and compare .....ie is more "Life like" important or is seeing everything clearly more important?

 

Turn Bloom OFF               ( make things look "soft" )

 

Adjust Focal Distance for the Scene  ...... to something Natural your eye would focus on 1m/3ft isn't enough most likely - it's too close to the camera

 

 

Mick.

 

                        Basic Tips on Lighting in CA.pdf

 

 

 

 

 

 

[marlem2000]

Many thanks  for the tips, Mick, and sorry for my late reply. Tons of problems and work in the last weeks. I'll update my template. I'm still struggling with lights. Probably I'm trying to do too complicated things.

I was planning to make a new post but, because it's about lights too, I'll leave it here...

Is there a method to iluminate a wall map from the background? I always wanted to do things like this but can't find a way.

 

By the way, I usually set the Manual Exposure to 6 or a bit less when I don't have light enough. The Daytime Backdrop Intensity is about 500 (Nightime at 20) and, if the color of the scene is too bright, I just add a bit of saturation or remove some brightness. I've been making many tries and the best configuration I could get is this one. 

[robdyck]

You could copy the map symbol so that you can place it directly behind the map symbol (which you probably want to have offset from the wall so it appears to be floating). Assign it a new material and make the new material 'emissive'. You may need to play with the amount of emissivity depending on your rendering technique.

This is what I'd try first.

[robdyck]

In the image below, I used the emissive technique on the right. On the left, I used an Added Light placed behind the symbol. I only used 1 just to save time.

This is a physically based rendering.

[marlem2000]

2 hours ago, robdyck said:

In the image below, I used the emissive technique on the right. On the left, I used an Added Light placed behind the symbol. I only used 1 just to save time.

This is a physically based rendering.

Definently, the Added Light technique is much better. I have used it some times. The problem is I can't configure really well lights in order to make them look properly behind objects.

I've been making tries aswel with the emisive option but light isn't enough for what I'm looking for.

Anyway I guess these two options are the easiest ones. I just need some practize... Tons of thanks, Robert!

[marlem2000]

What I usually do when I try to apply lights to a shape (for example, a mirror) is create a light first with that shape. Then, I apply white lighting as a material and, because of this is not enough, I add 4 lights to everything (in the example from the pictures I added only 2).
It's a mess and the result is not what I'm looking for but... something is something.