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Getting a more balanced lit render using Gamma 2.2
#1
I thought I would show you the option of using the Materials and lowering textures to 0.4545 Gamma and approx 2.2 Gamma in the Tone Mapping in ArtiCAD.

This is nothing new to rendering, especially for interiors, as if you google it Vray and many other rendering engines use this method to get a more natural and more balanced lighting without loosing colour that increasing exposure tends to do and also tends to increase the difference in light and dark areas.

It also has the following benefits:
Reduces the need to keep adding more light to areas further away from a light source/s
Lightens shadows which look more natural
Reflections are more correct (notice the Neff oven glass the Gamma1 has very little showing and the leather on the Chairs are more noticeable)
Gives you headroom for whites... this kitchen has white walls and really I need to lower the material slightly and even lower brightness of the lighting... but I think it's closer to the Brochure shot on the right for overall illumination compared to gamma 1.0.

If we have editable values to actually enter 2.2 rather than a slider it would be a lot easier... Tongue2



Gamma 1 Kitchen Crown Rococco Yellow, Light Grey and White Matt finishes:
resim

Gamma 2.2 ish Kitchen Crown Rococco Yellow, Light Grey and White Matt finishes:
resim

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#2
Daz, usually do this in photoshop rather than in articad as I can play around with levels, brightness and saturation as well. Also save as a .tiff format and keep original incase I want to try different edits saved in .png format.  ThumbUp

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#3
Not quite the same thing Joe as this method has gamma 0.4545 textures/colours on input so when Gamma 2.2ish is added the colours are correct. The RedSDK controls are also better because they do not introduce artifacts as these operate on live layers until we click on finish which currently we cannot make use of on any export image option as they are not a floating point HDR format. Tiff is a floating point format but its not mentioned in thr Redway docs... only HDR:

 "REDsdk provides support for some of the most popular image file formats including JPEG, PNG and HDR.

"The JPEG is a lossy format which gives very high compression ratio but only save images in RGB format (no alpha). The PNG format is a lossless format with smaller compression ratio than JPEG but with alpha support. Finally the HDR format must be the format of choice to save floating point images (32bit per component) with little lossless compression."


I also no longer "Render to file" because I prefer this method as it reduces further editing outside of ArtiCAD/RedSDK...

This Video explains it maybe a bit better for those interested although his 0.4545 and 2.2 gamma curve illustrations he explains them the wrong way round:




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#4
Daz, I understand that images and colours are set at 2.2 before so adding 2.2 gamma will wash them out but how can we get our textures and colours to 0.4545 in Articad? Or do we have to do this before.

Cheers ThumbUp

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#5
I have tried using the Diffuse factor and it does work to a degree for certain colours... especially whites but really we have to do it on our Photo editing and the diffuse factor reduces the saturation of colour when set low... I use the "Levels" in Serif Photoplus and enter 0.4545. You will notice the texture go darker obviously.

I am gradually building up my textures with "gamma 0-4545" and using Save As so I always have the original when I do a new design. Like I have said in many render engines we can set this automatically which saves all this conversion...


This shows Serif Photoplus Original Crown Rococco Yellow LH side, Crown Rococco Yellow Gamma down to 0.4545 Rh side:

resim
[-] The following 1 user Likes Daz Gizmo's post:
  • Joe Laughlin (25-10-2016 10:01 PM)

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#6
Cheers will give this method a good try over the next few days. ThumbUp
[-] The following 1 user Likes Joe Laughlin's post:
  • Daz Gizmo (25-10-2016 10:27 PM)

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#7
ThumbUp
We have to keep an eye on textures and colour that have values of 255 in either the Red Green or Blue. For example: White 255RGB if I try to lower to 0.4545 it stays at 255 in Photoplus so I use the colour pickup tool to look at the colours before applying 0-4545 and if they have a 255 in a colour I lower it first by 1 to 254 then do the 0-4545...  ThumbUp

What it also allows is using the exposure control more as the lighting is more balanced so the exposure is being applied more evenly.... benefits all round for me..
[-] The following 1 user Likes Daz Gizmo's post:
  • Joe Laughlin (25-10-2016 10:28 PM)

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#8
Daz

Tried to lower a dark grey and Blue to 0.4545 but they went totally black. When rendered i tried the gamma slider but couldn't get the colours back without making the room so washed out and even then the blue was still really dark. Only have photoshop and don't know if i'm doing it right with the gamma correction on the colours. Crazy2

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#9
Can you upload an example Joe (without a gamma correction) to the dropbox?

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