Normal t
A Normal tag defines the Vertex Normals (called "Normals" in the following), which are used to calculate the shading. Cinema 4D normally calculates these using the Phong tag itself (there is a command in the Phong tag to create a Normal tag). As soon as you create a Normal tag, or this is available, the Vertex Normals will be read from the Normal tag.
Depending on which tags are available:
- Only Phong tag present: The Phong tag controls the direction of the Vertex Normals based on the angle of the adjacent polygons. For angles below the defined threshold value (Smooth to), the Vertex Normals will be set to an average value of the adjacent polygons, which will create the impression of a smooth surface in the Viewport or rendering. If the angles are larger, each Vertex Normal will be set to the polygon Normal of the adjacent polygon and a visible edge will bcreated during rendering.
- Phong tag/Normal tag present: If a Normal tag is present, the Vertex Normals stored in it will be used. The settings in the Phong tag itself have no effect on the direction of the Vertex Normals, but they are still required for the evaluation. A Phong tag is therefore always required for the Normal tag to function correctly.
Since Cinema 4D 2023.2, Deformers, tools, PLA animations etc. can be applied to objects with a Normal tag without causing shading artifacts. Requirements: Deformers/tools/animations will not change the number of points/polygons and the polygon connections, i.e., the topology should not be changed by them.
A Normal tag is primarily used for these functions:
Edit Vertex Normals
You can use the Normal Edit Manager to align Vertex Normals as required. The Normal tag saves these changes.
Imported CAD models
Some NURBS modelers export relatively poor meshes, which is noticeable due to errors in the shading. Some formats therefore have the option of embedding so-called Vertex Normals (these are Normals that are available for each point; depending on the associated areas, this can be several Normals per point) in the file if you activate this in the corresponding program.
These are used exclusively to display or render final imported objects correctly. Please refer to the paragraph above.
As soon as you delete the Normal tag, Normal shading will be used.
In the Structure Manager, the Normals can be displayed numerically) and using the option Vertex Normals in the Viewport (sometimes averaged, however).
Vertex Normals generated by Fields
Normal tags can be created for each polygonal object (go to ) in the Object Manager. Normal tags are controlled by fields if desired.