View Full Version : Diffuse Shading

June 28th, 2015, 09:31 AM
I'm noticing that Trainz has introduced diffuse shading under objects and at the base of vertical faces (in Max it would be called ambient occlusion). This is only just noticeable:


If this effect were stronger, better still controllable per mesh, it would be a very useful additional tool. What is it and why is it so weak?

June 28th, 2015, 11:52 AM
That is screen space ambient occlusion (https://en.wikipedia.org/wiki/Screen_space_ambient_occlusion). You can control it via post-processing settings. It is impossible to make it controllable per mesh, because it is something like a photoshop filter, based on distance variations to from user to objects' pixels. If set it stonger, you'll obtain black nimbus around objects:

http://i.piccy.info/i9/c86d06b2dbbbf38f6242827e22905676/1435510326/83982/854143/Bezymiannyi_800.jpg (http://i.piccy.info/i9/c596758c56d411a58517d004561b9a24/1435510325/396744/854143/Bezymiannyi.jpg)http://i.piccy.info/a3/2015-06-28-16-52/i9-8409102/800x432-r/i.gif (http://i.piccy.info/a3c/2015-06-28-16-52/i9-8409102/800x432-r)

June 28th, 2015, 08:12 PM
More importantly, SSAO is a faked form of AO. It's "good enough" for most purposes, but it's not entirely accurate since it's a local estimation built from the output image, not from the source geometry. Simply making it more pronounced will not really improve the overall visuals, and will make the problem cases an awful lot more visible.