Questions about linked genetics

[Gwill]

Old rumours about alien eyes said that there was no alien eye texture; that the eyes would just show whichever eyes were in the alien skin tone textures.
I'm not sure if this is true.  The original game files do contain a separate alien eye texture, and a Texture Overlay XML.  The only material Definition I can find is in the Object.package itself, and does seem to point the eye textures to the adult and elder male alien skin tone textures.
I also confirmed something that has annoyed me before; Alien eyes are not enabled for teens.  If they're born with them, they'll keep them as they grow up, but if you try to create an alien teen in CAS, the eyes just aren't there; even in debug mode.
Alien eyes are also only available to sims with the alien skin tone.  I assumed that had to do with the way the eyes borrow texture from the skin tone, but it doesn't seem like that's the reason.  The limitation is in the Texture Overlay: skintone (dtString) = 6baf064a-85ad-4e37-8d81-a987e9f8da46

Generations ago, one of my sims had a close encounter of the 4th kind, resulting in an adorable green baby.  I'm still getting green babies once in a while, four generation on, but I'm also getting distinctly fleshy babies with black eyes.
So my question is; does the skintone (dtString) only apply to CAS sims, or other first generation sims and not to their children?  Or do I have a replacement or mod somewhere interfering with regular game behaviour?

I have a set of albino eyes I'm quite fond of (they're grey, with various levels of pink, rather than the blood red vampire eyes some creators seem to be under the illusion that albinos suffer from), which I have currently linked to the palest skin tone I have in my game, as well as geneticised as hyper recessive.  Because they are so recessive, I never get a second generation albino.
Is there any way to genetically link an eye colour to a skin tone, so that it is impossible to pass down one without the other?

Hmmm... I wonder if just adding hairtone (dtString) = 00000003-0000-0000-0000-000000000000 to the skin packag will force the game only to generate blonde sims with that skin...
This must be experimented with.

[eevilcat]

Apologies in advance if I've misunderstood what your asking but if you mean are the alien eyes linked to the alien skintone, or rather the presence of the alien eyes in a skintone, then I think the answer might be yes. This is Jax Ramaswami, an adult second generation alien spawn. His skintone is S4/S4 dominant/recessive and his skintone range is S4/S1 dominant/recessive. His eyes are alien/brown dominant/recessive but as you can see in the picture they are the funny light colour associated with the teenage aliens. Yes, he should have alien eyes, but I'm using a set of default replacement skintones (JWilson default hairy replacements from SexySims which are I believe modified Louis skins). I assume that the default replacements I use don't have the alien eyes. Indeed, I also use a default replacement alien skin and eyes as I don't like the originals - this is Jax's father, Jupiter Pescado, one of Pes's alien spawn. His skintone is alien/S1, skintone range alien/S1 and his eyes alien/gray. The fact that so many of us use different default replacements will probably result in the random appearance of alien eyes in non-alien skintones dependent upon what is in the replacement skintone.

(If you are interested I have been tracking my alien genetics in a spreadsheet, hence having this all to hand.)

[Zazazu]

His eyes are alien/brown dominant/recessive but as you can see in the picture they are the funny light colour associated with the teenage aliens.

I've never noticed this lighter color. Granted, I don't have a lot of alien spawn in my game, but I've had a few and they either had normal eyes or alien ones all through. Pic below of my former teenage triplets:

[Zeljka]

I think it's just teen boys that lose the alien eye colour, my female aliens have always kept theirs.

[Sleepycat]

my teen females always lost them too, course not now that I know to edit my default alien skintone replacements teen file (paste my alien eye replacement over the eye on the skintone)

[eevilcat]

I have thought about patching up my skintones for alien eyes but am loathe to do this as it will impact on the quality of the final skin in game. Texture compression is lossy so exporting the texture from SimPE, editing then reimporting/recompressing using the DXT utility will have a noticeable impact on appearance. You'd really have to get the original texture files from the creator and modify/import those.

[Gwill]

You'd really have to get the original texture files from the creator and modify/import those.

Or you could just edit the material definition in the original maxis alien eyes to use a different texture.  Much simpler, and no loss of quality anywhere.

All those bugs are easily fixed.  I want to know about linking genetics.

[eevilcat]

What I said still holds true if you are going to fix the problem by editing the skintone files. Now that I've woken up properly I see where you're coming from. It does appear that there might be a dud link somewhere, at least for teenaged aliens as there is in effect no eye texture being displayed hence it defaulting to what is on the skintone file. That doesn't explain why an adult with alien eyes but a non-alien skintone doesn't display the alien eyes correctly. I've looked at my spreadsheet and I've got another sim with alien eyes but displaying no texture, so they will do as guinea pigs. I will have a poke around when I get back from work. I suspect there is probably a missing or incorrect link to the alien eye texture/material somewhere. I'm intrigued.

[eevilcat]

I am happy to report success, here is Jax sporting his fixed alien eyes. The problem is all down to EAxis and how they are generating the customPart TXMT data in the character files. The teenage aliens and normal skintone sims are missing some vital data so they don't use the alien eye texture at all. I fixed it by hand in SimPE for a normal skintone as follows:

for each customPart txmt definition:

On the Properties tab:
Change baseTexture1 to baseTexture2
Add a new baseTexture1 with the value uuface-eye-alien (NB add creates a blank entry at the bottom of the list, once you have set the values, click the sort list button)

in compositeBaseTextureName: insert _uuface_eye_alien after the face txmt definition
e.g. I changed _tmface_s4_uuface_browcombed_black-diffuse to _tmface_s4_uuface_eye_alien_uuface_browcombed_black-diffuse

change numTexturesToComposite from 2 to 3 (this will use baseTexture0, baseTexture1 and baseTexture2, adding in the alien eye texture)

On the File List tab:
insert _uuface_eye_alien as per the compositeBaseTextureName value
e.g. I changed _tmface_s4_uuface_browcombed_black-diffuse to _tmface_s4_uuface_eye_alien_uuface_browcombed_black-diffuse

For sims with alien skintones, you only need to patch the teenage customPart TXMT (paramAge 2)