KeyShot Forum

Technical discussions => General discussion => Topic started by: joe on September 07, 2012, 12:17:29 pm

Title: Ombre
Post by: joe on September 07, 2012, 12:17:29 pm
How would you render something like the attached? Color for clear objects is controlled by the specular transmission, but specular transmission cannot reference an external texture like a jpg with gradient.
Title: Re: Ombre
Post by: br3ttj on September 08, 2012, 08:00:32 pm
Hi Joe!  Welcome to the KeyShot Forum!

Lately, I've been exploring materials, textures, and lighting FX through some Coca-Cola themed renderings.  Saw your post and thought it'd be a fun challenge to see if I could achieve a selectively tinted bottle effect like you're looking for.  For the rendering below I created a cyan gradient texture map in Photoshop that fades to transparent on top and bottom.  Then I adjusted the overall opacity to 30%, exported the file as a .png to communicate transparency and used it as a "label" on the bottle glass material.  After applying the label with cylindrical texture mapping in Keyshot, I adjusted the label intensity to 2.5 to help pop the color.  I also did a little post adjustment in Photoshop to pop the rendering and color even further.  Hope this gives you an option ;)
Title: Re: Ombre
Post by: guest84672 on September 09, 2012, 06:42:17 am
Really well done - thanks br3ttj!
Title: Re: Ombre
Post by: br3ttj on September 10, 2012, 10:03:29 am
Thanks Thomas, it was a fun challenge!

Another tip I learned for getting glassware to read more realistic is to apply a subtle ripple bump map to the inside surface of the glass.  As evident in Joe's picture, glass cools unevenly during processing.  By incorporating those imperfections I was better able to tease out the pooling of highlights and shadows that give glass its character.  I used KeyShot's "wavy-bmps-normal.jpg" normal map and just scaled it up.  In the rendering above it may be a little overt and could be dialed back just a bit.