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Getting no eye reflections

RafmerRafmer Posts: 564
in New Users

Hi! I'm doing a close-up portrait in Daz Studio 4.9 using Iray renderer. Everything is fine but the eyes appear dark; there is a spotlight right directly in front of her right eye, I assumed it should be reflected.

I have tried different settings for the cornea; thin glass, thin water; several refraction index (1.33 and 1.38). I have tried putting another small spotlight pointed at her eye from above and nothing. Caustics are ON on render settings... I don't know what else to try.

Here is a screen capture of what I'm seeing. What am I doing wrong? Thanks in advance.

 

no-reflect.jpg
1920 x 1080 - 470K

Comments

  • mjc1016mjc1016 Posts: 15,001

    What are the dome settings?

    If it is Dome only, then the scene lights aren't doing anything.  If the camera headlamp is on, then there is a chance that it is overpowering the scene lights.

  • Hiro ProtagonistHiro Protagonist Posts: 699
    edited May 2016

    I don't think this is a problem with your eye materials—it's a lighting issue. I think there are few factors here:

    • Point light spotlight. I'm assuming, from the sharp shadow, that this is what you are using. A point light will firstly need to be very accurately pointed at the eye so that it's reflected, and secondly the reflection will be quite a small point that doesn't spread reflection-wise. Try changing this to a rectangular mesh, say 100 width. You will need to increase the lumens, say to 15,000. The light source will be larger and will give the eye more to reflect. However, you may not like the shape of the light reflecting in the eye. A disc or sphere shape might work in this case, but might have similar problems as the point.
    • Dark coloured iris. These are not going to bounce as much light around, and even using a mesh type spotlight, in this kind of lighting the eyes may still be too dark outside of the actual reflection of the light source itself. When I have problems with lighting in eyes it's often when they are darker coloured.
    • Overhanging hair. This could be preventing sufficient light from reaching the eye.
    • Closed environment with low lighting. You will be reliant on your direct lighting and won't get any help from the environment.

    Obviously the last three points cover what you actually want the scene to look like, so changing them isn't really a useful solution.

    If you are really stuck, you could cheat by rendering again just for the eyes, hiding the entire hallway and using an environment dome. Then combine the renders in an image editor (i.e. erasing all but the eyes on the "eyes" render and adjusting fill or layer mode until it blends in nicely). I've done this a number of times when I couldn't get eyes to light up.

    Post edited by Hiro Protagonist on
  • RafmerRafmer Posts: 564

    Thank you both for your help; I was using dome and scene, and the camera headlamp is OFF.

    Yes, the spot light is using a point as geometry; I will try making it bigger. If not; or I don't like the results, I'll make a separate render for the eyes as you suggested.

  • mjc1016mjc1016 Posts: 15,001

    Also, make sure that you are using the Cornea Bulge morph...set it somewhere between 90 and 100%.

  • nonesuch00nonesuch00 Posts: 18,333

    I got eye reflections by deleting the specular maps for the sclera and cornea and setting the Top Coat Roughness to 1.0 for both and it I remember right the Top Coat Roughness for the sclera to 0.4 and the cornea to 0.3.

  • RafmerRafmer Posts: 564
    edited May 2016
    mjc1016 said:

    Also, make sure that you are using the Cornea Bulge morph...set it somewhere between 90 and 100%.

    It was already at 100%.

     

    nonesuch00 said:

    I got eye reflections by deleting the specular maps for the sclera and cornea and setting the Top Coat Roughness to 1.0 for both and it I remember right the Top Coat Roughness for the sclera to 0.4 and the cornea to 0.3.

    I checked and there were no specular maps for either surfaces and their roughness values were even lower, but thanks anyway.

     

    Finally; changing the geometry of the spotlight to a disc and increasing its size to 50x50 was enough to get it reflected and lightning is not bad either. So, thank you all for your answers, you were very helpful.

    Post edited by Rafmer on
  • RafmerRafmer Posts: 564
    edited May 2016

    Sorry, doble post.

    Post edited by Rafmer on
  • nonesuch00nonesuch00 Posts: 18,333
    Rafmer said:
    mjc1016 said:

    Also, make sure that you are using the Cornea Bulge morph...set it somewhere between 90 and 100%.

    It was already at 100%.

     

    nonesuch00 said:

    I got eye reflections by deleting the specular maps for the sclera and cornea and setting the Top Coat Roughness to 1.0 for both and it I remember right the Top Coat Roughness for the sclera to 0.4 and the cornea to 0.3.

    I checked and there were no specular maps for either surfaces and their roughness values were even lower, but thanks anyway.

     

    Finally; changing the geometry of the spotlight to a disc and increasing its size to 50x50 was enough to get it reflected and lightning is not bad either. So, thank you all for your answers, you were very helpful.

    If the Roughness values are too low you will get only a very small pin point of reflection and the opposite at high values of 100% or above 60% is the reflection surface will be so 'rough' it will seem not to be reflective at all. I had to do tests and vary the values between 0.0 - 0.6 for the 2 models I've done that with so far. I guess the except value that will give the result you wants depends on the model & the lighting. I used only HDRI environment.

  • RafmerRafmer Posts: 564

    Here is the final result in case you were curious about it. It's a small reflection, but at least the eye is no longer a hole in her face.

     

    loca2.png
    835 x 1080 - 1M
  • nonesuch00nonesuch00 Posts: 18,333

    looks super good

  • RafmerRafmer Posts: 564
    nonesuch00 said:

    looks super good

    Thank you! :)

  • Hiro ProtagonistHiro Protagonist Posts: 699
    Rafmer said:

    Here is the final result in case you were curious about it. It's a small reflection, but at least the eye is no longer a hole in her face.

     

    Glad you got that sorted—the reflection on the eye surface looks good. I thought it would be the lighting rather than surfaces or geometry. Possibly the material of the iris might be adjusted to get more reflection in the dark colour, but I've not had much luck with that.

  • ToborTobor Posts: 2,300
    edited May 2016

    Only the outer surface of the eye will (or should) reflect light. Anything else could cause internal reflections, and that can lead to fireflies. This can be a problem because in many Daz characters, there are multiple eye surfaces stacked one on top of the other. That can be a problem for Iray when these surfaces are transparent or semi-transparent, so exercise care in selecting the surfaces.

    The eye glint didn't show up because when a spotlight or point light is set to Point, the size of that point is infinitely small. If there's any reflection at all, it is extremely tiny. You always need to change the emitter type to a geometry, and enlarge it. Keep in mind the size values are in centimeters, and of course, the distance from the light to the subject matters. 

    Post edited by Tobor on
  • RafmerRafmer Posts: 564

    Yeah thanks, got that lesson learned for the next one. I usually don't change any eye parameters except cornea and maybe the lacrimals, since they tend to appear too white for my taste.

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