New fresnel textures

[jeanphi]

Hi,

I've just added fresnel versions of the band, bilerp, mix and multimix textures. Those are hardly physical but should enable some interesting creative usage.

Jeanphi

[pciccone]

Hi Jeanphi. Thank you for thins new addition. Would it be possible to see some examples of usage?

Thanks in advance.

[jeanphi]

Hi,

Do you mean renders or syntax?

Jeanphi

[pciccone]

Both
But syntax is the most needed. Thanks!

[jeanphi]

Hi,

The syntax is the same as for the float and color versions:

Code: Select all

#You can have as many offsets as you want in the band texture
Texture "myband" "fresnel" "band" "float offsets" [0.1 0.5 0.8] "texture amount" ["myamount"] "texture tex1" ["fresnel01"] "texture tex2" ["fresnel05"] "texture tex3" ["fresnel08"]
#The bilerp texture accepts a "string mapping" parameter with values "uv", "spherical", "cylindrical" and "planar", each one having subsequent tuning knobs
Texture "mybilerp" "fresnel" "bilerp" "texture v00" ["fresnel00"] "texture v01" ["fresnel01"] "texture v10" ["fresnel10"] "texture v11" ["fresnel11"]
Texture "mymix" "fresnel" "mix" "texture amount" ["myamount"] "texture tex1" ["fresnel0"] "texture tex2" ["fresnel1"]
Texture "mymulti" "fresnel" "multimix" "float weights" [0.1 0.5 0.4] "texture tex1" ["fresnel1"] "texture tex2" ["fresnel2"] "texture tex3" ["fresnel3"]

band is like a mix with more intervals, multimix is a freeform mix with constant weights (the weights are not normalized to 1 and you can have as many as you want), bilerp is a bilinear interpolation between all 4 textures using the specified coordinates.

Jeanphi

[J the Ninja]

At the least they'll allow the fake-birefringence trick with glass2.

Btw, piciccone, multi-mix is easier to understand if you think of it as an "add" or "stack" node. Basically, each input is multiplied by its weight, and then they're all summed.

[J the Ninja]

Jeanphi, something seems wrong with the fresnel band. Bilerp works fine, but this gives "[Lux 2011-Sep-08 17:53:27 ERROR : 14] Static loading of fresnel texture 'band' failed."

Code: Select all

# Materials File

Texture "Tex" "fresnel" "band"
   "float amount" [0.186000004410744]
   "float tex1" [1.560321807861328]
   "float tex2" [20.000000000000000]
   "float offsets" [0.000000000000000 1.000000000000000]

MakeNamedVolume "glass" "clear"
   "texture fresnel" ["Tex"]
   "color absorption" [0.00000000 0.00000000 0.00000000]

MakeNamedMaterial "Material"
   "bool architectural" ["false"]
   "bool dispersion" ["false"]
   "string type" ["glass2"]



[neo2068]

Jeanphi, something seems wrong with the fresnel band. Bilerp works fine, but this gives "[Lux 2011-Sep-08 17:53:27 ERROR : 14] Static loading of fresnel texture 'band' failed."

Code: Select all

# Materials File

Texture "Tex" "fresnel" "band"
   "float amount" [0.186000004410744]
   "float tex1" [1.560321807861328]
   "float tex2" [20.000000000000000]
   "float offsets" [0.000000000000000 1.000000000000000]

MakeNamedVolume "glass" "clear"
   "texture fresnel" ["Tex"]
   "color absorption" [0.00000000 0.00000000 0.00000000]

MakeNamedMaterial "Material"
   "bool architectural" ["false"]
   "bool dispersion" ["false"]
   "string type" ["glass2"]



There was a typo in band.cpp. Should be fixed now.

[J the Ninja]

Jeanphi, something seems wrong with the fresnel band. Bilerp works fine, but this gives "[Lux 2011-Sep-08 17:53:27 ERROR : 14] Static loading of fresnel texture 'band' failed."

Code: Select all

# Materials File

Texture "Tex" "fresnel" "band"
   "float amount" [0.186000004410744]
   "float tex1" [1.560321807861328]
   "float tex2" [20.000000000000000]
   "float offsets" [0.000000000000000 1.000000000000000]

MakeNamedVolume "glass" "clear"
   "texture fresnel" ["Tex"]
   "color absorption" [0.00000000 0.00000000 0.00000000]

MakeNamedMaterial "Material"
   "bool architectural" ["false"]
   "bool dispersion" ["false"]
   "string type" ["glass2"]



There was a typo in band.cpp. Should be fixed now.

yep, seems ok now

[jeanphi]

At the least they'll allow the fake-birefringence trick with glass2.

No, it won't. It will at most fake mixing liquids with different IOR. Birefringence is an entirely different story, it needs support at the material level.
And thanks neo2068 for fixing my silly typo.

Jeanphi