digi Mike: matching single light references wip

Hi there,

I have been trying to match references of single flashlight from 6 camera angles based on our RC1 data and hit a wall getting consistent spec across 6 camera angles.

The main issue I am facing is as I match the skin based on camera 3 (front-on), the spec will appear to be dimmer (or lack of spec) in camera 1 and 6 render than in the references. However, if I approach it the other way around by matching camera 1 or 6 first, then the spec will appear to be too strong in camera 3's render than the reference.

The example above is based on a single VrayAlsurface to explain the issue I have. I have slightly tweaked the hue of the diffuse map and increased light intensity to accommodate using a VRay physical camera.

- No spec map. Single spec lobe. Roughness 0.42. IOR 1.45. GGX distribution.

- single scatter map is blended as usual.

- Meso displacement * 1 + Micro-disp map * 0.01

I have tried tweaking the roughness, IOR, adding a 2nd or even a 3rd very broad "sheen-ish" spec lobe, different approaches of layering/blending spec lobes, or custom fresnel curve. I couldn't get consistent results spec intensity between a front-on camera (cam 3) and a side camera (cam1 & 6). As a 1st pass, I would like to get consistent result across 6 camera angles without painting additional control maps but no luck so far after many hours of tweaking.

Trying to figure out what could be a typical cause of this and what I have missed to set up for consistent spec lobe across camera angles. If any of you read this and can shed some light, I'd really appreciate it.

Another issue that I noticed is the shadow under the chin is much brighter in all renders regardless which parameters I tweaked and it seems mostly coming from the reflection AOV.

It's not as obvious in the screencaps but when A/B the two, it's fairly prominent.

Looking for suggestions to fix this.