Hi
Ive been using Houdini 16 now for three weeks and I first started with apprentice version and now with Core. In neither I can see no ambient occlusion in the viewport ( SSAO ). Even if I enable High Quality Lighting + Ambient Occlusion I see no difference. Enabling also reflections from the same place makes no difference.
I have GeForce GTX 1080 Ti card and my driver version is 378.92, what Im doing wrong?

SSAO is scale dependent, sometimes it doesn't do anything. Reflections haven't ever worked. I'm not sure why the option exists.

In order to see reflections, you need to either have a metallic material (a Principled or Classic shader will do, with Metallic > 0) or a material with the GL Reflect or GL Material parm on it (or tagged), set to a value > 0. This will give you a reflection of the elements in the scene around it.

If you want simple environment map reflection, add an Environment light with a environment map. For a single object, add the GL Environment Map parameter to its material using Edit Rendering Parameters > Material Options > OpenGL on the material node.

SSAO uses the Scene Scale to determine its effective radius. You can also change the level in the Display Options, effects tab from 1 to 4 to increase or decrease its area of effect.

Also, you need at least one light in the scene or HQ Lighting will not kick in.

yeah, adding a light did it. thanks