Exterior render : need help with my settings

[madcoo]

Hi guys,

I've been using Octane for a while now (2-3 years) and I'm going crazy, especially with Exterior renderings.
I just can't get something that looks natural or photo-like, even after all this time practising...
To me this looks like a completely awful image.

Could someone tell me what I'm doing wrong ?
Should I change some settings in the Render Kernel for example ?
Why, even if I change the camera film, do I get this unnatural, blueish hue to my white walls? (yes I know in real life the sky is blue, but white buildings are white when we look at them, not blue...)

I've posted the image below as well as my settings.
No post-prod or anything, just Octane render so you can see what comes out straight from my settings.

Your help would be much appreciated.
Many thanks in advance

PMC - 3175 samples (in another test I let it run up to 16000 samples, but there's little difference)
Sunlight environment because I can't get the trees' shadows nicely laid out onto the walls with HDRs...

[ROUBAL]

Why, even if I change the camera film, do I get this unnatural, blueish hue to my white walls? (yes I know in real life the sky is blue, but white buildings are white when we look at them, not blue...)

Hi, Madcoo. It is because human eye/brain do a White Balance correction. Digital cameras also have a White Balance correction, but Octane hasn't. Son the physical blue sky is very presnt on white surfaces.

About the lack of realism, I think that your white surfaces would require, even very slight, a minimum of texture (roughcast). EDIT: There is some, but not enough visible, due to lack of bump probably.

I am currently encountering the same problem, because I am working on a very large and detailed city scene, and as I don't really know hom many textures I will need, and will be available, many buildings are not yet textured with real (I mean photo) textures.

Procedural textures can often be used, but they are not enough realistic in many cases.

Do not also forget the use of Bump or RGB Normal maps. Some of your stone walls look a bit flat imho. Also play with gamma on somme texture which look like washed-out.

Try also to use more specularity on your glasses (windows) Currently they look like diffuse with alpha instead of glossy with alpha and specularity.

Also make sure that the windows will reflect something : facing trees or cloudy sky instead of the empty sky of the daylight system.

In general, always give to glossy/specular materials like glass, car paints, water and chrome something to reflect. Otherwize you will get a poor effect.

[suvakas]

Welcome to the club.
You can't define a white point in Octane.
Developers opinion is, that this is something you should do in post.
So I think we will not see White balance feature in Octane any time soon.

Suv

[ROUBAL]

I also see that you are using PMC kernel. I am not sure, but PMC is imho more useful for interior view with few lighting coming from lamps or narrow windows, or night scenes outside.

Outside scenes can be well lit using Pathtracing when there are glossy/specular materials (windows, water), and even with Direct lighting if there are no glossy/specular materials.

[sdwhitton]

I'd agree re using PMC - not really necessary for this, direct lighting with an AO setting of 5 would probably be more than fine

if I look at the corner with the ivy on it, that is starting to look realistic to me, so I'd say it's your model, the lack of detail in it and materials as against the
rendering... particularly the curtains - pretty sure you could find some better 3d models for them?

and then your materials, I'd be tempted to use black and white images from the 'grunge' section on www.cgtextures.com and add them as specular maps to glossy materials for things
such as the metal window frames and the pots

could have a lower sun, exterior photographs generally look a bit more interesting late afternoon / early morning..?

if you're using the version of octane that allows instancing, then I'd be tempted to model clumps of grass, if you haven't already too - the grass is too 'foreground' in the image
to not have it in '3d' rather than a bitmap maybe?

one final thing - your camera target height should be the same as your camera height.... very important for archviz...!!!

just my thoughts, hope it's helpful!

[FractalBuddha]

When I render windows, I had some turbulence bump with large scale and not to much strength.
If you look at the reflections of a real window, you will see it is not perfectly flat.

[sdwhitton]

http://www.viewpictures.co.uk/Details.a ... only=False

http://www.viewpictures.co.uk/Details.a ... only=False

http://www.viewpictures.co.uk/Details.a ... only=False

[madcoo]

Hi everyone, many thanks for all this precious input.

I'm gonna make some tests with all the tips you gave me.
So, many many thanks to you all.


I'll post my tests in this topic so you can see what I'm doing, and maybe help me further in the light of what I produce.
I think I'm gonna "start over", i.e going back to basics.
I'm gonna model some objects and render them.
- although I know that it's the overall composition of an image that makes it realistic or not -

See you soon then, and thanks again !

[madcoo]

Hi guys,

As promised, here are a couple of tests :
- the amphora with a "Grunge" bump texture applied onto it
- a stone wall to which I applied a "displace" modifier in Blender so I get the displacement from the stones

I'll post some more pics little by little

Cheers,

M.

[sdwhitton]

that wall looks great!