--- title: "V-Ray Material Refraction" canonical: "https://documentation.chaos.com/space/VC4D/116855190/V-Ray%20Material%20Refraction" format: markdown --- The Refraction tab is part of the V-Ray Material parameters. ## **Refraction** --- > Macro (anchor) --- > Macro (anchor) --- ### Example: Refraction Glossiness ## **Translucency** --- > ✅ As the new translucency modes perform multibounce volumetric light scattering, they require closed objects. > Macro (anchor) --- > Macro (anchor) --- ### Example: Scatter Color ## **Refraction Advanced** --- > Macro (anchor) --- ## **Notes** --- - The new translucency modes perform actual volumetric multibounce scattering inside the object, therefore they are influenced by the actual geometry quite a bit. Widely used “cheats” like smooth surface normals may not be enough for low-poly meshes, especially with a small scatter radius. In this case, subdividing the mesh either using V-Ray subdivision or e.g. the Turbosmooth modifier improves the results. V-Ray subdivision is slower to render, but is able to tessellate the mesh in a view-dependent manner without having to guess the number of subdiv iterations. - V-Ray provides several other ways to achieve sub-surface scattering, for example the [V- Ray Fast SSS2](https://docs-chaos.atlassian.net/wiki/spaces/VC4D/pages/116855182) and [V-Ray ALSurface](https://docs-chaos.atlassian.net/wiki/spaces/VC4D/pages/116855184) materials. These materials use various approximations for the sub-surface scattering effect in order to speed up the calculations. In many cases, they produce a decent result. However, in more complicated scenarios, the approximations may be inaccurate.
Comparison between sub-surface scattering methods The approximation used in the VRayALMtl assumes a mostly flat surface; therefore, in areas of great geometric detail and relatively large scattering radius, it tends to produce inaccurate results that don't capture the details very well. In addition, the Directional mode of the VRayALMtl material may introduce unwanted color shifts. ![image](media://294b389b-5608-417f-9604-f0a91deed6cc) ![image](media://20e57681-a95e-47fa-8bd5-8dc8012892cd)