Interior Archviz Scene - HDRI Lighting Problem

Swizl

Active member
#1
Does anybody have any tips on lighting interior architectural scenes with an HDRI? I have a few scenes that I pulled in from the SketchUp warehouse that have no windows / opening to the outside world. I know I can put lights in the scene, but how can I get the HDRI to show in these models without removing the ceiling? Most of the interior scenes I've done before, I've just removed the ceiling (or a wall behind the camera to let some light from the HDRI in). But it would be helpful if there was a better way.

Any help would be greatly appreciated. Thanks!
 
#2
Have you tried putting a plane behind the camera with a photo, adding another copy of the same photo to the "emissivity" map, maybe even an HDRI photo (the real kind, not the fake tone mapped "goth" look "HDRs)?
 

Swizl

Active member
#3
Have you tried putting a plane behind the camera with a photo, adding another copy of the same photo to the "emissivity" map, maybe even an HDRI photo (the real kind, not the fake tone mapped "goth" look "HDRs)?
Thanks for the reply Bill!

I've never tried that before. The only issue with that will be having to UV map the wall(s). I'll give it a try on a simple scene though and see how it works out.
 

frank beckmann

Well-known member
#4
Oops - in essence you have a closed box with a camera inside and want it lit by a HDRI to render with Falcon? Is that correct?

Cheers
Frank
 

Swizl

Active member
#5
Oops - in essence you have a closed box with a camera inside and want it lit by a HDRI to render with Falcon? Is that correct?

Cheers
Frank
Yes, that's it. Either Falcon or the Original C3d Renderer would do. This problem appears in any 3d app I've tested it in. So I don't know how people that do Archviz full time get around that issue when it arises? I tried searching Google and I can't find anything pertinent.
 

Swizl

Active member
#7
I think that´s technically just not possible ( and logical - at least to me) for a room - let it be a cellar, bunker or dungeon. No single light source? Why HDRI when no window or at least a peephole is there?
With Cheetah renderer you can render with Ambient Occlusion without any light source.
But no HDRI-ray will make it inside.

Cheers
Frank
Ok, it makes sense. I just wasn't sure if there was another way to cheat using an HDRI. Since there isn't, I'll resort to either creating a hole and/or placing some lights in the scene.

Danke
 

Swizl

Active member
#9
Wouldn´t it look weird to have say the sun/environment as a reflexion on a mirror or glass objects inside a closed box? Just asking.

Cheers
Frank
Yeah, but I usually use a very unsaturated somewhat blurry studio HDRI for most of my stuff with a few strategic CG lights. Mostly they're close up renders on signage hanging on a wall or from a ceiling. The metal parts are all brushed Aluminum, so they don't have hard reflections either. But those issues you mentioned would be something to take in to consideration typically.
 

Swizl

Active member
#13
Ok, I'm not sure if Martin has a problem with me posting this. I modeled it in C3d and then put the plant and computer props in from the Modo library. Then I rendered it there. I removed the ceiling on this one, but it was easier since the camera could be pointed down a little. I guess I can try removing the floor and rotating the HDRI if I need to render a ceiling mount sign. I haven't tried that before.

arris Workstation Panel Clip.JPG
But this is the idea. Not great, but it should be ok for our catalog. Some of our big competitors have really bad ones, so I don't feel too bad. :p
 

frank beckmann

Well-known member
#14
If you just have this kind of camera angle and close-ups you can delete everything except the floor maybe - no big deal. Is this just lit by a HDRI light source? I ask because of the shadows.
I really had something different in mind. :giggle:

Cheers
Frank
 

Swizl

Active member
#15
Yep, I'll see how it goes. All the backplates I tried hard to get the camera matches on, are mostly junk. A lot of the angles are terrible and then cropping in close just doesn't work. I tried doing render passes with much higher resolution and then composited them in Photoshop, but they still mostly look pretty terrible. So now I'm just going to try and set a bunch of different scenes up in all 3d. That way I can control the angle and finishes in the background.

What's in your mind is probably a magnitude greater than what I can create. :D

Edit:
Yes it's one HDRI and then two lights. A stock Directional Light and then one Area Light to the right to give the frame a highlight. Without the extra Area Light, the panel clip just disappeared into the frame and didn't look right.
 
Last edited:
#17
It's probably the same Frank had in mind, but you could model an environment, with light sources, some fancy architecture, windows and stuff (and use there a HDRI if you want), render it as big HDRI, use the model as a prop to align your stuff to, make the room-prop invisible and render with the selfmade HDRI. That would be faster than rendering all those things for each product (and of course you could create some variants of the HDRI).

You still would need some furniture etc, of course. But camera matching wouldn't be that big a problem anymore. Just a thought if you need to show a bit more than the closeups.
 

Swizl

Active member
#18
It's probably the same Frank had in mind, but you could model an environment, with light sources, some fancy architecture, windows and stuff (and use there a HDRI if you want), render it as big HDRI, use the model as a prop to align your stuff to, make the room-prop invisible and render with the selfmade HDRI. That would be faster than rendering all those things for each product (and of course you could create some variants of the HDRI).

You still would need some furniture etc, of course. But camera matching wouldn't be that big a problem anymore. Just a thought if you need to show a bit more than the closeups.
Thanks, this could be another work around. I thought about taking a sphere Andy putting it inside the windowless room. Then applying a material with the HDRI plugged into the emissive channel. The I put a render tag on the sphere so it wouldn’t show up, but it ended up rendering black anyway. Possible I didn’t do something correctly, but would have been nice if that method did work. Cheers.
 
#19
Hi Swizl

Actually it's nothing else: Modo can render to a spherical map (see camera options, instead of perspective). You probably will have to take a deeper look, especially if you will have some reflections that are clearly seen or a visible part of the background (the hdri should probably be at least 6 times as big as the end resolution of your picture in that case). If you could work with dof instead a much smaller hdri would suffice. No problem you wouldn't have with your method.

Your method should also work, btw. Probably you forgot something (like putting a luminous intensity in the material. luminous color alone isn't enough), or your camera is somehow wrong positioned or something with the clipping.

I personally think the spherical map hdri is the cleaner solution. For modeling, you can go very low poly, no need for edge beveling and stuff (just use rounded edge width). Maybe another time you will want more detail and model it out (it's quiet easy. Especially with the spherical map hdri. You just create a good room, could even texture a good floor, have a ceiling with the typical office lights, put some furniture in it and so on. Then just position the camera in the center (i. e. there where you will put your product models) and test it out. Even if you don't get it quiet right, it probably would be enough and whatever time you use you get back in shorter render times (by the way. area lights make for very slow renders. You could use mesh lights instead which should be a bit faster).

What I would recommend, too, is to create more backgrounds than just one, so you'll have a bit of diversity in the product photos.

Good luck
 

Swizl

Active member
#20
I’m finding it relatively easy to download models from SketchUp (Trimble) warehouse, clean it up, modify it to my needs. I retexture some parts and then render. This one I did yesterday. Not super photorealistic yet, but I’m getting closer.
D9E0E2BE-0E91-41DB-8238-4B7DB682A037.jpeg
 
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