From 84094e1f75171ba9ccd74ad14a0f74a74d089a1d Mon Sep 17 00:00:00 2001 From: Bartosz Kosiorek Date: Thu, 7 Mar 2024 17:28:20 +0100 Subject: [PATCH] Shaders: Upgrade description of Principled BSDF parameters --- .../render/shader_nodes/shader/principled.rst | 28 +++++++++++-------- 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/manual/render/shader_nodes/shader/principled.rst b/manual/render/shader_nodes/shader/principled.rst index 951ffb1ed..ca9e248df 100644 --- a/manual/render/shader_nodes/shader/principled.rst +++ b/manual/render/shader_nodes/shader/principled.rst @@ -52,6 +52,7 @@ Base Color Roughness Specifies microfacet roughness of the surface for specular reflection and transmission. + A value of 0.0 gives a perfectly sharp reflection, while 1.0 gives a diffuse reflection. .. figure:: /images/render_shader-nodes_shader_principled-roughness.webp :align: center @@ -70,7 +71,9 @@ Metallic Metallic from 0.0 to 1.0 IOR - Index of refraction for specular reflection and transmission. + Index of refraction (:term:`IOR`) for specular reflection and transmission. + For most materials, the IOR is between 1.0 (vacuum and air) and 4.0 (germanium). + The default value of 1.5 is a good approximation for glass. .. figure:: /images/render_shader-nodes_shader_principled-ior.webp :align: center @@ -93,11 +96,11 @@ Normal Subsurface ---------- -Subsurface scattering is used to render materials such as skin, milk and wax. +:term:`Subsurface scattering` is used to render materials such as skin, milk and wax. Light scatters below the surface to create a soft appearance. Method - Rendering method to simulate subsurface scattering. + Rendering method to simulate :term:`Subsurface scattering`. :Christensen-Burley: An approximation to physically-based volume scattering. @@ -112,13 +115,13 @@ Method Random walk method optimized for skin rendering. The radius is automatically adjusted based on the color texture, and the subsurface entry direction uses a mix of diffuse and - specular transmission with custom IOR. This tends to retain + specular transmission with custom :term:`IOR`. This tends to retain greater surface detail and color and matches measured skin more closely. Weight Blend between diffuse surface and subsurface scattering. - Typically should be zero or one (either fully diffuse or subsurface) + Typically should be zero or one (either fully diffuse or subsurface). .. figure:: /images/render_shader-nodes_shader_principled-subsurface-weight.webp :align: center @@ -146,7 +149,7 @@ Scale Scale from 0 cm to 50 cm IOR :guilabel:`Cycles Only` - Index of refraction used for rays that enter the subsurface component. This may be set to + Index of refraction (:term:`IOR`) used for rays that enter the subsurface component. This may be set to a different value than the global IOR to simulate different layers of skin. .. figure:: /images/render_shader-nodes_shader_principled-subsurface-ior.webp @@ -156,8 +159,8 @@ IOR :guilabel:`Cycles Only` Anisotropy :guilabel:`Cycles Only` Directionality of volume scattering within the subsurface medium. Zero scatters uniformly - in all directories, with higher values scattering more strongly forward. - For example skin has been measured to have an anisotropy of 0.8. + in all directions, with higher values scattering more strongly forward. + For example, skin has been measured to have an anisotropy of 0.8. .. figure:: /images/render_shader-nodes_shader_principled-subsurface-anisotropy.webp :align: center @@ -181,7 +184,7 @@ Distribution which would otherwise be visible as excessive darkening. IOR Level - Adjustment to the IOR to increase or decrease intensity of the specular layer. + Adjustment to the :term:`IOR` to increase or decrease intensity of the specular layer. 0.5 means no adjustment, 0 removes all reflections, 1 doubles them at normal incidence. This input is designed for conveniently texturing the IOR and amount of specular @@ -226,7 +229,7 @@ Anisotropic Rotation :guilabel:`Cycles Only` Anisotropic rotation from 0.0 to 1.0 Tangent - Controls the tangent for the *Anisotropic* layer. + Controls the tangent direction for anisotropy. Transmission @@ -267,7 +270,7 @@ Roughness Roughness from 0.0 to 1.0 IOR - Index of refraction of the coat layer. Affects its reflectivity as well as the falloff of coat tinting. + Index of refraction (:term:`IOR`) of the coat layer. Affects its reflectivity as well as the falloff of coat tinting. .. figure:: /images/render_shader-nodes_shader_principled-coat-ior.webp :align: center @@ -334,9 +337,10 @@ Color Emission color variations Strength - Strength of the emitted light. A value of 1.0 will ensure that the object + Strength of the emitted light. A value of 1.0 ensures that the object in the image has the exact same color as the *Emission Color*, i.e. make it 'shadeless'. + .. figure:: /images/render_shader-nodes_shader_principled-emission-strength.webp :align: center -- 2.30.2