I just modelled my first eye in blender. It also has an outer sphere that I made clear and glossy to mimic a cornea. The only issue is the cornea I modelled has this staticky look to it. The static gets worse when I am performing a zoom in/out and also when I move or rotate around the object. I believe that is why I added a noise texture and volume scatter node hoping that playing with those settings would make it to where you can see the cornea, but it would just be smooth and glossy with no static. Any tips on what could fix this?
Picture of eye. Inner sphere and outer sphere are separate not joined or merged.
One cannot tell exactly what would be best hereā¦ Two cropped images, donāt give us any information about your geometry, if different objects, their relations, normal orientations,and so onā¦
But right at first sightā¦ Delete your material. Purge it completly, not only from your file, but from your memory.
If, as you say, thereās an inner and an outer sphere (which, i suppose itās āSphere.002ā), then the proper material would be just a shader mix of Glass and Transparent BSDFs, using LightPath.IsShadowRay as factor. (Start from here, and if something needs a tweek, will later see)
The inner sphere, should have almost no specularity. Though we donāt know much about it either, at least the texture looks to be in place; so probably it doesnāt need any rework. But just in case, if any problem persist, please include also the material and the geometry alone in shaded or wireframe.
Apologies I just realized how itās difficult to tell which sphere the nodes screenshot even relates to. The nodes in the second picture are in relation to the outer sphere which is separate from the inner one. They arenāt joined together. The inner sphere was created like most procedural eye tutorials show how to make them. I simply took a UV sphere pushed some faces inward where the iris would be, and then applied shade smooth. The white color and iris color were all added using nodes in the shade panel.
I made the outer one with a UV sphere also. Shade smooth was applied to that one as well. The transparent and glossy look on the outer sphere was achieved using the nodes seen in the second screenshot.
Deleted the nodes from the second screenshot like you suggested and tried this one. It definitely looks like glass and becomes transparent before the light path is added to the group. However, when light path is connected to Fac in the way it is in the above screenshot, it just makes the outer sphere not transparent anymore at all. Downside to leaving light path disconnected from anything is the glass effect is too harsh/strong to pass as a cornea.
Yes, I will try to provide more. Iām sorry for not elaborating a bit better from the first draft of this post. Hope Iām not frustrating you.
If you are needing me to turn one of the layers off or to put one of the spheres in wireframe mode I will try that too if it makes things easier to understand.
This is what it looks like without the light path connected to the outer sphere.
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This is what it looks like with the light path connected to Fac. I also circled the layers to show that both spheres are still visible and in separate layers. They arenāt connected.
Is there a way to make the glass effect less harsh and just leave the light path out of it? I know not to mess with the Fac setting on the mix shader when the light path is not connected to it cause all that does is just make the outer sphere look staticky again.
Ok. This simply means that youāre using Eevee for rendering this! (You should always start with this information when youāre asking something about rendering results)
With Eevee, thereāre no Rays, so there are no shadow rays also, and no refractions and the type of eye you need to have, needs to be modified manually to accomodate the lack of raytracing from Eevee.
That said, your only chance is to set your material as a mix between glossy and transparent, using fresnel as a factor. Also, you should change the ārender methodā to allow transparent shadings.
The cornea should have a different depth to fake the refraction. And the inner sphere must be bigger and its surface must be closer to the outer sphere.
In those images, you are in the material preview mode, which means that the material uses Eeveeās transparency settings.
Go in the material settings and find this section:
Where it says āditheredā, change that setting to āblendedā. This is going to make the transparency much more smooth. The blended mode can have problems with showing faces in the wrong depth order, but this is a simple object so it should be fine.
If you were to keep using the dithered mode, you could clean it by increasing Eeveeās main render samples. But this is necessary only for more complex transparent objects.
Thank you! This got rid of the issue super-fast. Most of the beginner procedural eye tutorials I watched on YouTube never went over the dithered and render view settings. They kind of just assumed most beginners Blender settings would already look like this. Since those tutorials didnāt go that deep into it and left a lot of gaps, it made it to where I couldnāt really type my question as thoroughly as I could have. Glad to know these settings exist now.
Yeah, itās usually assumed you are going to learn how materials work before going into procedural textures, as that is the more advanced topic of the two. And material settings are to some extent a pre-requisite to understand textures, because textures are used to modify material settings.
