Better details/depth on headlight & taillights?

[JeffPatton]

What's the best way to get more details from layered objects like headlights & taillights?  I've tried cranking up the max ray depth to the max setting of 100 and using a high max sample intensity value.  However, I just can't seem to get a good detailed depth on the lights.

I've found that GPU applications (iray+, Octane, and VRay R/T) seem to produce better depth on my headlights/taillights.  Is it the way the lighting calculations are done, materials, or just something I've overlooked?

For reference I've attached an example comparison between Corona (1.5) and Iray+

Thanks!

[Ludvik Koutny]

This looks more like material/lighting setup issue to me. First of all, I would re-render both iRay reference and Corona render in completely linear output. Meaning no tone mapping on both of them.

Secondly, do you think you could post screenshots from both iRay and Corona materials for the tail light red glass as well as chrome used inside the light case?

First two things that come to my mind:

1, IOR on chrome material in Corona version is not high enough, and you could lower glossines a little if it's all the way up to 1. Even lowering it to 0.9 can light up the chrome a lot. For IOR, try to set it all the way to 999, and make sure reflection color is 100% white.

2, Since corona uses different colorspace, it's possible to set colors so strong and saturated they are out of visible spectrum. I am not sure if you use refraction color or absorbtion for the red glass, but generally I would try to set value of the red color all the way to 255, and reduce saturation a bit, to something less than 230, just as a test.

[JeffPatton]

Good points, I appreciate that.  I'll gather up the material info and configure the tests in a more linear configuration.

[Juraj]

Did you try settings Maximum Ray intensity  to 0 (unbiased mode) to see if it's not also dimming the intensity ? I've noticed multiple refractions/reflections can quickly loose intensity.

[Fluss]

Did you try settings Maximum Ray intensity  to 0 (unbiased mode) to see if it's not also dimming the intensity ? I've noticed multiple refractions/reflections can quickly loose intensity.

Which brings us to this :

[JeffPatton]

This looks more like material/lighting setup issue to me.

Well, you were correct as usual.  The 'problem' was within my reflector metal material.  I used a saved chrome material from my library.  This chrome material used the ComplexFresnel shader for reflection color (chrome preset) which darkened the reflectors.  I'll either use a brighter preset on the complex fresnel shader, like aluminum, or just 255,255,255 for my reflectors.

Attached some updated renders & a reference photo (red car).  In looking at some reference photos and comparing the renders I believe the iray+ render was actually unrealistically bright now. 

I appreciate the help.

[Ludvik Koutny]

Glad it got sorted out :]