62 lines
3.6 KiB
Markdown
62 lines
3.6 KiB
Markdown
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# Fresnel Equation Node
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## Description
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The Fresnel Equation Node adds equations that affect Material interactions to the Fresnel Component. You can select an equation in the **Mode** dropdown.
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You can find Numerical values of refractive indices at [refractiveindex.info](https://refractiveindex.info/).
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## Ports (Schlick)
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| Name | Direction | Type | Binding | Description |
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|:------------ |:-------------|:-----|:---|:---|
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| f0 | Input | Vector{1, 2, 3} | None | Represente the reflection of the surface when we face typically 0.02-0.08 for a dielectric material. |
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| DotVector | Input | Float | None | The dot product between the normal and the surface. |
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| Fresnel | Output | same as f0 | None | Fresnel coefficient, which describe the amount of light reflected or transmitted. |
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## Ports (Dielectric)
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| Name | Direction | Type | Binding | Description |
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|:------------ |:-------------|:-----|:---|:---|
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| IOR Source | Input | Vector | None | The refractive index of the medium the light source originates in. |
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| IOR Medium | Input | Vector | None | The refractive index of the medium that the light refracts into. |
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| DotVector | Input | Float | None | The dot product between the normal and the surface. |
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| Fresnel | Output | same as f0 | None | The fresnel coefficient, which describe the amount of light reflected or transmitted. |
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## Ports (DielectricGeneric)
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| Name | Direction | Type | Binding | Description |
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|:------------ |:-------------|:-----|:---|:---|
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| IOR Source | Input | Vector | None | The refractive index of the medium the light source originates in. |
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| IOR Medium | Input | Vector | None | The refractive index of the medium that the light refracts into. |
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| IOR MediumK | Input | Vector | None | The refractive index Medium (imaginary part), or the medium causing the refraction. |
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| DotVector | Input | Float | None | The dot product between the normal and the surface. |
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| Fresnel | Output | same as f0 | None | Fresnel coefficient, which describe the amount of light reflected or transmitted. |
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## Controls
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| Name | Type | Options | Description |
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|:------------ |:-------------|:-----|:---|
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| Mode | Dropdown | • **Schlick**: This mode produces an approximation based on [Schlick's Approximation](https://en.wikipedia.org/wiki/Schlick%27s_approximation). Use the Schlick mode for interactions between air and dielectric materials. <br/>• **Dielectric**: Use this mode for interactions between two dielectric Materials. For example, air to glass, glass to water, or water to air.<br/>• **DielectricGeneric**: This mode computes a [Fresnel equation](https://seblagarde.wordpress.com/2013/04/29/memo-on-fresnel-equations) for interactions between a dielectric and a metal. For example, clear-coat- to metal, glass to metal, or water to metal. <br/>**Note:** if the **IORMediumK** value is 0, **DielectricGeneric** behaves in the same way as the **Dielectric** mode. ||
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## Generated Code Example
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The following example code represents one possible outcome of this node.
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```
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void Unity_FresnelEquation_Schlick(out float Fresnel, float cos0, float f0)
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{
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Fresnel = F_Schlick(f0, cos0);
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}
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void Unity_FresnelEquation_Dielectric(out float3 Fresnel, float cos0, float3 iorSource, float3 iorMedium)
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{
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FresnelValue = F_FresnelDielectric(iorMedium/iorSource, cos0);
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}
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void Unity_FresnelEquation_DielectricGeneric(out float3 Fresnel, float cos0, float3 iorSource, float3 iorMedium, float3 iorMediumK)
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{
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FresnelValue = F_FresnelConductor(iorMedium/iorSource, iorMediumK/iorSource, cos0);
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}
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```
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