First interior attempt - questions

[afecelis]

Hi guys,

After working a bit with an exterior scene, here's my first attempt at an interior:


Comments are welcome. There's a lot to improve and I'm very interested in improving my skills.

Questions:
1. Though the floor is reflective, I'm not getting reflections (or they're too subtle). Is it the angle of the camera (fresnel)? Or should I crank the glossy level higher?
2. Is using invisible area lights the only way to get light in further areas inside?
3. Even when setting the area light to invisible, if you check the lower right image, you can see it reflected on the balcony's window/glass. How do you make it invisible on reflections as well?
4. I tried using a huge invisible area light on the ceiling but I moved it to anothe rlayer on this render. Is it ok to do this to get light all over the scene or is it better to use smaller area lights per space?
5. The only metal I got is a diffuse black with the glossiness cranked up to white, an IOR of 20 and some fiddling with the Anisotropy, but all I'm getting is a black ultra glossy material. How do you set up steel/aluminum/gold/chrome, properly? I'll dig into the material forums for info, but if anyone has some nodes on this regard I'd totally appreciate it.
6. If you check the lower right image you'll notice a a light on the ceiling. I tried it out both with a meshlight as well as with an emissive material, but it's only working on the original light, and the one outside the terrace, in all the other copies the emissive light is not working. I tried both copies and instances and the result is the same. Any ideas why the light is not emitting energy in the copies?

that would be it so far. Thanks for all the help

regards,
Alvaro

[andybot_cg]

It doesn't look like you're getting any daylighting into your scene. Do you have a domelight or world environment adding lighting from outside?

There do seem to be some odd things going on with your materials, it's hard to tell if it's because of the oddly even lighting or if it's the material setup.

Here is a quick setup of how I would do metal. The main thing is that you want to uncheck fresnel reflections so you get a more metallic reflection. 1. change to GGX type 2. adjust intensity of reflection 3. reduce glossiness so it's not a mirror reflection 4. turn off fresnel reflection.

For an emmissive shader, I think what you're looking for is the Light material. I would keep the multiplier low, like 1.5, and put a spotlight in place for the actual light source. Also, I typically keep the ceiling cans as a separate object and in the object render settings, I turn off visible to GI.

[afecelis]

great!

Thanks a lot Andy, your help is very valuable and guides me into different directions to explore and learn this wonderful render engine.
So, I decided to start with something simpler. Now I learned a bit more about Vray's Physical camera, which I wasn't using, and this allowed me to use much higher Illumination values both for the dome and the sun light:

However, this brought a whole new bunch of questions and issues. For instance, I'm using a fog color for the glass in the railing but it's not showing up even when cranking the fog multiplier to high values. I also noticed DOF has to be set up different and that now I gotta use DSLR values for the camera. So I tried some of this stuff on the previous interior:

And now I'm able to get a sun light through the windows but I'm now getting a vignette effect that I have to check in the physical camera's settings. I was also able to increase the dome and area lights value and this is helping the scene considerably, but now no emitter materials/objects are displaying so I'm sure it's the very high lighting killing the emitters so I must look for a way to balance them or change the emitter units.

I also tried your material settings for metal and It's showing better on the couch's feet, I forgot to update it for the chairs but I'll try it out next.

Still, I know I have a long way to go but with the help of you guys each little step feels like a huge advance.

thanks a lot! I'll keep on posting

PS. RT is gonna be a blessing for testing stuff on the fly!
PS2. Is blender's f-stop 3dsmax's fnumber?

[afecelis]

Hi everyone,

Next try:

Getting a better hang of V-ray's physical camera, white balance, and materials. It's great to see that most of the documentation written for other programs (i.e. 3ds max) is easily translated into blender's parameters. Andrei has done a great job there.

More questions coming up!

regards,
Alvaro

[chadstevens]

Hi Alvaro,

The images are coming along nicely.

What lighting setup are you using? It seems that the lighting is very flat, it looks as if you are using an ambient light. You want to have an extremely bright sun outside in order to get the light to bounce correctly through the interior, you will have to adjust the camera exposure to compensate for such brightness.

I'll link you to a Blender Guru tutorial that I think will help in this regard. https://www.youtube.com/watch?v=m9AT7H4GGrA

I hope this helps.

Cheers.

[andybot_cg]

Hi Alvaro,

What are your rendering settings. Can you share a screenshot of your "Globals" and "GI" panels? I'm wondering if something is not set right for global illumination.

Andy

[afecelis]

@chadstevens: thank you so much for the tips and the link to the tutorial, I'll check it out right away. I got a couple of questions. I read somewhere that when rendering using IBL you shouldn't use a light generating hard shadows like the sun and that all shadows/reflections should come from the hdr/exr being used. Is this not an issue in V-ray? Is the balance between the 2 lights (IBL/Sun) achieved only through the physical camera's parameters? I've tried both using a dome light (hemi) and a world environment with a texture. The dome light tends to overburn the scene and the world tends to darken it. Which is better to use between the 2? I read in the forums that some people use both with the same hdr on them. Is this a proper practice?

ps. I had already seen Andrew's tutorial on color space and filmic blender, but this only works for cycles. Is there something similar for V-ray blender?

@Andy: thanks a lot for commenting. I'll post my settings in a minute. I've been running lots of tests trying to understand the balance between V-ray's sun and the environment lights and the physical camera. Last night I was trying this scene out:


And tonight I'm working with this one, which is helping me a lot at understanding how to get a better hang of it :


About settings, I'm using Irradiance map+Light cache with almost all at default values. But if you want to check my render/camera settings better please download the scene of the last image here (I only removed the exr from the dome light so please add one of yours and reconnect the node, right now it's rendering white):
http://www.telardigital.com/afecelis...nterior_02.zip

I'll post more detailed screenshots of my settings on my next posts.

thanks for all the help guys. This is a very enriching experience

regards,
Alvaro

[chadstevens]

As far as the Filmic blender, there are some downloadable LUT's, you can find more information as well as the download link here: https://forums.chaosgroup.com/showth...c-OCIO-and-LUT

[chadstevens]

When it comes to IBL you should never need to use two lights (for the main lighting i.e. sun), the HDR itself contains all the lighting and reflective information you could want (assuming the HDR is of a good quality), some people use an HDR along with a vray sun to compensate for a badly photographed HDR, if you want to learn more about HDR here is a good link, it explains what HDR clamping is and how you can test it: http://www.hyperfocaldesign.com/hdri...clamped-hdris/

[afecelis]

When it comes to IBL you should never need to use two lights (for the main lighting i.e. sun), the HDR itself contains all the lighting and reflective information you could want (assuming the HDR is of a good quality), some people use an HDR along with a vray sun to compensate for a badly photographed HDR, if you want to learn more about HDR here is a good link, it explains what HDR clamping is and how you can test it: http://www.hyperfocaldesign.com/hdri...clamped-hdris/

Thank you Chad. But then if I only use a Sun light in blender-Vray, the world/env will remain black. Is there an option to have the sun light enable a sky model with it? That's why I'm using both basically, to get a blueish tint in the sky (from the hdr/exr). I'm about to post some new screenshots and a new model to share.

Thanks for all the help and info.

[chadstevens]

I'm not familiar with blender, but the Vray sun always enables a Vray sky in 3ds max, I can't see why it would be different in Blender. If you look through the Vray maps, you should see a Vray sky map, this is created by default in 3ds max, but if you had an HDR to start with it will not overwrite it. This might not be the case in Blender, but I cannot see a reason why there would be a Vray sun but no Vray model.

[chadstevens]

You'll see here that there seems to be an option for direct or sun, it needs to be set to sun in order to get the sky model (I think ) https://docs.chaosgroup.com/display/VFBlender/Sun

[afecelis]

OK, here we go

Sun light only (black env/world):


world/environment with hdr:


domelight (couldn't match the same angle as the world version, and had to lower its intensity a lot since it was overburning everything):
EDIT: I found out that changing its color space to linear makes its intensity behave the same as the world/env.


here's my color balance file:
http://www.telardigital.com/afecelis...normal1.vccglb

and here's the scene in case you guys want to run your own tests If you make any changes or improve stuff in it please share the file back. I modeled this scene in blender a long time ago based on an old vray for max tutorial. I have kept using it for testing purposes ever since with every render engine I've tried to learn:
http://www.telardigital.com/afecelis...yhall_vray.zip

quick questions, which IBL method is better? Dome light (hemi) or world+environment texture? Is there a significant advantage of one over the other? Which portal version is better to use portal or simple portal?

thanks!

regards,
Alvaro

[afecelis]

You'll see here that there seems to be an option for direct or sun, it needs to be set to sun in order to get the sky model (I think ) https://docs.chaosgroup.com/display/VFBlender/Sun

yup, that's the one I'm using. Thanks a lot for all the info and links. I really appreciate it.

[chadstevens]

Okay, and is that giving you a black environment? Sorry for my lack of blender knowledge, I don't imagine it helps the situation haha.