Wood material? Also Water not transparent...

[manitwo]

a <specular> material is a transparent material (glass/water/sss/...) - and its right you can't texture it.

EDIT: btw, can anybody tell me how to decrease the specular value of a <phong> material?

if you work with an 0.7t version then theres no <specular> tag within phong - it has been replaced with the <ior> tag which do basicaly the same but uses other numbers. So the ior controlls the specularity of the phong mat.
to your other question: you also can texture a diffuse material. A diffuse material is the same as a phong but without the ior/specular component.

btw, i think common coated wood isn't as specular as glass(which has an ior of 1.52), so an ior of 3 for your wood is pretty unrealistic (i would choose an ior of < 1.5)

[nikolatesla20]

I think the wood looks fine.

But it does look like you have some "normals" problem on the base of the glass, you have two dark spots on each side. This is because the normals are weird.

do a search in the forum about "normals black" and you can find some info about why and what to do about it. Basically, for your glass it would be best to seperate the bottom off of it, or add many more faces on that 90 degree turn...

-niko

[CTZn]

EDIT: The IOR really does seem to have a huge impact to the visibility of the texture. I think this solves my problem. Let's see...

Reminds me what Ono said about phong, it behaves like a coated material... So maybe you set the IOR too high, thus making the floor very reflective; and since every reflected ray misses the diffuse substract, it makes the texture darker*. That's logical I think, manitwo and you are right about ior.

btw, i think common coated wood isn't as specular as glass

Are you sure ? In my mind varnish has a high density (it's a solid), to be verified. I'm just unsure


* albedo applies to diffuse substract only, it doesn't alterate the phong lobe at all.

[mrCarnivore]

@manitwo: Thx for the info about specular material. It's reallly confusing, that the IOR determines the specularity of the <phong> material. They should have kept the old <specular> tag for that!

@nikolatesla20: I know what normals are and how to check for inverted normals. And I did this check before I rendered. Moreover I dont see the spot where the normals are supposed to be facing the wrong way. The only dark areas I see are near the bottom of the glass. However, this cannot be because of normals facing the wrong way, because the outside of the glass is a simple tube with no extra loops near the bottom.
To be sure that the lack of extra loops (I did use subsurf level 3) does not cause anything weird, I added a few extras and the dark areas went away. Thx for the tip about me using to few loops.

@CTZn: Thx, for the info. Helped me a lot. But I must mention again, that I think the tag <IOR> is very confusing! I can only image that they chose it because the IOR is a physical value and can be measured unlike the specularity...

[CTZn]

But I must mention again, that I think the tag <IOR> is very confusing! I can only image that they chose it because the IOR is a physical value and can be measured unlike the specularity...

Specularity can be mesured as an angular data I think... anyway, they choosed ior because of the law of conservation of energy:

Conservation of energy states that the total amount of energy in an isolated system remains constant, although it may change forms (for instance, friction turns kinetic energy into thermal energy). In thermodynamics, the first law of thermodynamics is a statement of the conservation of energy for thermodynamic systems.

So by defining how much light (as energy) is reflected (what ior does), one can say the exact amount of light the albedo strate receive. It's very simple and physically correct, I think these are the reasons why.

But you are right, this is not intuitive at all... practice !