Author Topic: Lacking Realism  (Read 8059 times)

2018-09-21, 18:31:16

RichieCUK

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Hi all,

I've been creating an interior scene in 3DSMax and Corona. I'm using a HDRI map to light the scene and a lot of the materials I am using are from the Corona Material library or modified materials from the libaray but my render just seems to lack that realism. My question is what am I missing?

Here is a high res test render, I didnt denoise it but just a quick render to show you where I am at.

Any help would be greatly appriciated.

Many Thanks,

Rich

2018-09-21, 18:58:15
Reply #1

mferster

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a few things Immediately jump out at me.

-Everything is too clean and uniform, eg Your Walls, crevices and furniture. Your materials are too uniform to be realistic. Try and make use of the corona AO maps to layer in some grunge as a jumping off point.

-Your lighting in your scene looks too uniform as well, it feels as if it was lit by a giant softbox.  I would ditch the HDRI you are using and start with corona sun and sky. Add some contrast and interest to your scene.

-Your scene doesn't feel 'lived in', it kinda just feels like random furniture plopped in (the artwork is especially random).

Hopefully these things give you a jumping off point to do some exploration.

2018-09-21, 19:00:33
Reply #2

PROH

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Hi. The light looks very "flat". Check if the HDRI is set to Spherical. If that doesn't help, then find a better HDRI or use a daylight system + Corona sky.

Hope it helps

2018-09-21, 23:25:20
Reply #3

RichieCUK

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Thank you for your feedback guys.

I think this is why I am struggling. I was following the interior tutorial on Corona's Youtube page and and his set up is just a HDRI map for the lighting.

Is it better to go with Corona Sun/Sky and then use a HDRI map in the reflection and refraction override slots to get more detail that way?

Again with the materials in the tutorial his materials arent that advanced and I even copied his process for the sofa material, yet his results just seem a lot better.

Would it be best to white everything out and concerntrate on getting the lighting right first?

2018-09-21, 23:31:53
Reply #4

RichieCUK

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This is the image im referencing. I've not finished modelling everything yet

2018-09-22, 00:42:28
Reply #5

mferster

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So comparing this image to yours:

-The contrast from the sun drives this image ( it has interesting shadows. It looks like there is an open door just outside the frame  to the left of the TV based on how the light is hitting the center table)
-Small details add up to a lot (eg. actually modelling the floor planksrather than just a texture, the small reveal gaps between the floor and floor boards, the open cupboards, need more of a over hang on your window sill, gaps in the different parts of your window, etc.)
-Your window construction looks incorrect, now that I look a bit closer.
-the reflections in this scene add a bunch of interest in this photo (even though it's subtle even the wood furniture has reflection I can see, where it's not present in your render.)
-If you want to match this view exactly you can use the perspective match utility in 3ds max, to match it perfectly.

Try these settings in your tone mapping.

Exposure:  (adjust second last until it looks right)
Highlight compress: 0.8
white balance: adjust last until it looks right
contrast: 2
saturation: -0.02
Filmic Highlights: 0.3
Filmic Shadows: 0.6

2018-09-23, 09:19:20
Reply #6

sprayer

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Reference image is cg render too, it have not realistic light, you can  see in it sun from  the back  window and pretty strong light from the left widnow what is can't be strong that much, just looks at shadows directions and you see it. So you trying  to achieve  fake light / Try to setup corona sky and two light  source sun  from  back  and another from the left  window. Turn off bump at wood surfaces add more detail to wall ceiling etc
« Last Edit: 2018-09-23, 09:26:43 by sprayer »

2018-09-23, 21:35:57
Reply #7

RichieCUK

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OK guys. Thank you for the feedback. When I get into work tomorrow I will do some more test renders with Corona Sun/Sky and share the results.

Should I add a HDRI map into he reflection and refraction override slots so I get better reflections etc?

2018-09-24, 10:53:06
Reply #8

RichieCUK

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mferster I used your settings and got the following results.

I've only used Corona Sun/Sky.

I tried it in a few different postions and played with the exposure.

I'm not looking to 100% match the lighting in the photo/render I just want to learn how to get good lighting and a good balance.

I've noted the exposure settings in the image file names.

« Last Edit: 2018-09-24, 11:02:54 by RichieCUK »

2018-09-24, 11:38:17
Reply #9

RichieCUK

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Here is the last render with Ao set to multiply 30%

2018-09-25, 09:37:47
Reply #10

RichieCUK

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Anyone able to offer me any help or advice please?

2018-09-28, 11:10:36
Reply #11

maru

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Have you seen our YT tutorials? Ludvik is explaining very well in there how to set up a scene realistically, and also we have a "common user errors" tutorial:
- Interior project (6 parts!) - https://www.youtube.com/watch?v=0ybKcICtx2I
- Common errors - https://www.youtube.com/watch?v=8CC5Gn431wA

Other than that, here are some of my quick notes:
-Can you post a render with materials of your latest setup?
-Adding AO to everything in Corona is not a good idea - it definitely won't make your image look more realistic. You can use it for "artistic" effects, or to add a layer of dirt to everything.
-Make sure you are using good quality models. For example, if you take a look at this shot https://forum.corona-renderer.com/index.php?action=dlattach;topic=21809.0;attach=91043;image you can see that the flat faces on most of the furniture are unnaturally smoothed, making them look like assets from an old video game.
-Make sure you are using correct albedo (brightness) of the materials taking large part of the image (walls, ceiling). For example, in the reference image, you can see that the walls are actually pretty dark (grey) - you can see that especially in the shadowed areas. In your 1st render the walls are extremely bright, almost glowing.
-Other than that, try paying more attention to the details - how bumpy a surface is? What should be its glossiness? How reflective is it? Maybe try rendering some views from a different camera angle to see what could be improved there.
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2018-09-28, 16:07:50
Reply #12

RichieCUK

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Hi Maru,

Thank you for the feedback.

I will take some screenshots on the materials I was using in my last setup.

I've made a point of rendering everything in a plain white material atm to get the lighting down.

If I am to add an AO layer to my render and use it to add dirt to the scene how do I do this?

I understand about my ojects being smooth but would this be overcome by good materials/textures and using the correct glossiness and bump?

What I plan to do is take each model in the scene and then create the materials for them one by one. Rendering say the sofa on its own until I looks right and then add each item back into the scene


2018-09-28, 16:12:09
Reply #13

RichieCUK

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Here is my sofa model.

Please find attached a couple of renders in a simple HDRI lit scene with a screenshot of my materials I've used and how the model looks in wireframe.

Also with displacement, is the correct way in Corona to add the Corona Displacement modifier to the stack and then link the bitmap I want to use to create the displacement? Because if I try and link a bitmap to the displacement slot in a Corona material nothing seems to happen.

Also I am missing a texture for the seams on the sofa. I'm currently unwrapping them and will texture soon.