Materials behavior between KS2 and KS3

[Xidor]

Guys, I was hoping to get some advise and input on the three renderings posted above. The model was built in SolidWorks 2010 and set-up in SW. The model was then imported into KS2 and then KS3 separately. Also I find that curved parts require I use the old importers in KS3 or else the curved surfaces look like large facets.

I was originally creating the above images to show Thomas on another thread how decals show up very dark in KS3 when opening a KS2 file. The image above shows the difference. Image 1 is the original KS2 render. Image 3 is the KS2 file opened and rendered in KS3. The blue in the label looks almost black! The label image was created in Adobe Illustrator and saved as a PNG.

I was surprised though to see how the materials are not behaving similarly between KS2 and KS3. Image 2 shows the exact same model imported into KS3. I used settings to set-up the glass and liquid interface as described by Jeff McCartney in his wine glass tutorial. Works great in KS2. But using the same settings in KS3, it doesn't behave the same. The glass is solid and the liquid is dielectric using the same settings I used in the KS2 file. The environment is the same and rotated in as closely to the same between the KS2 and KS3 file.

I also used the same settings for Ray bounces and shadow quality. It appears that the Gamma is higher in the KS3 render, but the gamma controls for environment is different between KS2 and KS3.

The glass and liquid quality is a lot better looking to my eye in the KS2 render. The KS3 render is pretty flat. I used 24K gold for the bottle cap. It looks great and reflecting the environment in the KS2 render. The KS3 render's reflections are pretty lost. The old IOR controls are not the same either.

I tried adjusting Contrast in the KS3 file. That's not there in KS2(?) I tried brightness and I tried the Refraction index controls to no avail. So I am lost here. Also interesting here, the glass and liquid settings set-up in KS2, when that KS2 file is opened in KS3, the materials behave as they did in KS2, except the decal of course.

I recently did a render of an iPhone in KS3 and the glass screen and metals are reflecting nicely as you can see below. I'm particularly fond of the turned surface of the two screws.  So I know glossy glass is possible in KS3. Just not sure why it's not working on that bottle.



Thanks for any help!

Nelson

[KeyShot]

First, let me start by emphasizing that the materials in KeyShot 3 are identical to the materials in KeyShot 2 - except for enhancements such as specular maps and opacity maps. The differences you are seeing are most likely due to the different gamma setting in KeyShot 3. A higher gamma value with unchanged materials and lighting will indeed result in a flattened appearance. The easy fix to this is to reduce the gamma value to a setting of your liking. Since the gamma setting compensates for a non-linear intensity mapping in the monitor, and most monitors have a gamma around 2.2, it is more correct to adjust the material settings to reflect the higher gamma value. KeyShot 3 also exposes a contrast value in the textures that enables a higher contrast, which compensates for the higher gamma value.

-- Henrik

[Xidor]

Hi Henrik,

Thanks for reviewing my post and commenting. I just re-imported the bottle in KS3 and as before, I can see in the Settings Tab before I do anything that Gamma is up at 2.0. In KS2, Gamma was always 1.2.

However I'm trying to still understand why and how the liquid material and glass materials have to be adjusted to suit this higher Gamma setting. I actually did try to adjust all those settings and rotate the environment and I couldn't get the glass to be as reflective of the environment. And I could not get the liquid glass interface to reflect all those great high lights and hot spots on the bottom of the bottle like KS2 did. I sort of started to get reflections to show up, but nothing like the results in KS2.

I also discovered that the new glass and liquid materials already have the settings that Jeff McCartney suggested in his tutorial, so I used those materials in a test this morning. That is nice!

There must be something I'm missing.

[KeyShot]

The reflections will still be there, but there will not be as much contrast with a higher gamma setting. If you want more contrast from the environment then you can adjust the contrast setting in the environment tab. You can also make the liquid less transparent (darker), which will make the reflections relatively brighter - if you
brighten the overall image you should be able to get pretty close to the KS2 appearance.

That being said. If you like the lower gamma setting better then you can absolutely use it - that is why we left it in there ;-)

-- Henrik