Various options are grouped together in the Rendering panel to help you display the model as you wish or correct certain results coming after exporting models from design softwares.
The rendering options
These options are used to change the rendering mode of the model and take effect after the pending changes are published. The result is visible after a few seconds due to the reprocessing of the 3D model: a refresh of the page is necessary.
Face culling (Default value: True)
When the option is activated, only the faces of the geometries whose normals point towards the camera are visible.
The option can be turned off to enable double-sided rendering of geometry. It is useful for visualizing the front and back sides of simple surfaces like a curtain, a net..
Texture with transparent areas (left) used in a material applied to spheres.
When the option is activated, the front part of the spheres is visible (center).
When the option is off, the whole sphere (including the inside of the back part) is visible (right).
Vertex color (Default value: False)
Vertex colors are the old way of tinting a surface. Each vertex defines a color that applies to the triangles that it supports. The option must be on to activate the vertex color channel defined in a geometry. Otherwise, the information is simply ignored.
Gamma correction (Default value: False)
In PBR materials, textures used as base or emissive source are supposed to be encoded in sRGB color space while simple colors (materials without textures) are defined in linear RGB space. It means that values used to code the same tint trough a texture and a single color are not the same. As it is not always easy to correctly prepare the values and ensure that a texture is correctly encoded, this option applies a correction on single colors to align them with texture tints. Note that may not produce the original desired colors as textures themselves are not affected: the compensation is always applied on single colors.
(left) A plane composed of 2 areas using 2 different materials: the left one using a texture and the right one using a single color. Both texture and color represent the same tint.
In this example, without correction (middle), the final rendering shows a disparity between the 2 areas because the values chosen are incorrect (the same values were used for the single color and the color of texture pixels but they are expressed on 2 different colors spaces). When activating the option, the single color is compensated and the area looks like the textured one (right).