c4d.PolygonObject

Inheritance

Members

PolygonObject.__init__(pcnt, vcnt)
Parameters:
  • pcnt (int) – Point count.
  • vcnt (int) – Polygon count.
Return type:

c4d.PolygonObject

Returns:

The object.

PolygonObject.GetPolygonS()

Return the selected polygons.

Return type:c4d.BaseSelect
Returns:A reference to the selected polygon structure.
PolygonObject.GetPolygonH()

Return the hidden polygons.

Return type:c4d.BaseSelect
Returns:A reference to the hidden polygon structure.
PolygonObject.GetEdgeS()

Get the selected edges. The edges are indexed by 4 * polygon + edge where polygon is the polygon index and edge is the edge index between 0 and 3.

Warning

If you change this selection you must make sure that its still valid, so that shared edges have a well-defined selection status. it is safer to use SetSelectedEdges().

Return type:c4d.BaseSelect
Returns:A reference to the selection of visible edges.
PolygonObject.GetEdgeH()

Get the hidden edges. The edges are indexed by 4 * polygon + edge where polygon is the polygon index and edge is the edge index between 0 and 3.

Note

The edges are only hidden within the editor.

Warning

If you change this selection you must make sure that it is still valid, so that shared edges have a well-defined selection status. It is safer to use SetSelectedEdges().

Return type:c4d.BaseSelect
Returns:A reference to the selection of hidden edges.
PolygonObject.SetPolygon(id, polygon)

Set a polygon.

Note

Call obj.Message (c4d.MSG_UPDATE) after you set all your polygons to update the object.

Parameters:
  • id (int) – The index.
  • polygon (c4d.CPolygon) – The polygon to set at index id.
Raises:

IndexError – If the polygon index id is out of range : 0<=id<GetPolygonCount().

PolygonObject.GetPolygon(id)

Get a polygon.

Parameters:id (int) – The index.
Raises:IndexError – If the polygon index id is out of range : 0<=id<GetPolygonCount().
Return type:c4d.CPolygon
Returns:The polygon at index id.
PolygonObject.ResizeObject(pcnt[, vcnt=-1])

Change the number of points and polygons in the object. If vcnt is -1 or not set, the method of PointObject.ResizeObject() is used.

Parameters:
  • pcnt (int) – The new number of points.
  • vcnt (int) – The new number of polygons.
Return type:

bool

Returns:

Success of changing the number of points and segments.

PolygonObject.GetPhongBreak()

Get the phong break edges. The edges are indexed by 4 * polygon + edge where polygon is the polygon index and edge is the edge index between 0 and 3.

Warning

If you change this selection you must make sure that its still valid, so that shared edges have a well-defined phong break status. it is safer to use SetSelectedEdges().

Return type:c4d.BaseSelect
Returns:The phong break.
PolygonObject.GetPolygonTranslationMap()

Gets a translation map from polygon indices to N-gon indices.

Return type:tuple(int, list of int)
Returns:The number of N-gons and the list of N-gon indices. (0, []) if the function failed.

Changed in version R19.024: Was only returning the list of N-gon indices.

Note

With list as the N-gon indices map, if list[i] == p then polygon i is part of the N-gon p.

PolygonObject.GetNGonTranslationMap(ngoncnt, polymap)

New in version R19.024.

Gets a translation map from N-gon indices to polygon indices.

Parameters:
Return type:

list of (list of int)

Returns:

The polygon index map if successful, otherwise None.

Note

The number of polygons in N-gon i is stored in list[i][0]. Then the polygon indices are stored in list[i][j] where j goes from 1 to list[i][0].

PolygonObject.GetAllPolygons()

Returns all polygons.

Return type:list of CPolygon
Returns:A list of copied polygons.
PolygonObject.CreatePhongNormals()

Returns a list with the stored phong normals of the object.

Return type:list of Vectors or None
Returns:The list or None if the object has no Phong Tag.
PolygonObject.GetPolygonCount()

Returns the count of polygons. Is the fastest way to get the count of polygons.

Return type:int
Returns:The count.
PolygonObject.GetPolygonR()

New in version R18.011.

Gets the start of the read-only array of polygons.

Note

While this function may sound trivial and cheap, internally it is not. For performance reasons, it is not recommended to use this function inside a loop or inside a loop condition.

Return type:PyCObject
Returns:The start of the read-only polygon array.
PolygonObject.GetPolygonW()

New in version R18.011.

Gets the start of the writable array of polygons.

Note

While this function may sound trivial and cheap, internally it is not. For performance reasons, it is not recommended to use this function inside a loop or inside a loop condition.

Return type:PyCObject
Returns:The start of the writable polygon array.
PolygonObject.GetSelectedEdges(e, ltype)

Get the selected, hidden or phong break edges. The edges are indexed uniquely by a Neighbor object, so each edge has a single index.

Note

This is a convenience wrapper around GetEdgeS(), GetEdgeH() and GetPhongBreak().

Parameters:
  • e (c4d.utils.Neighbor) – The neighbor object with information about the edge topology. Must be initialized with all polygons, i.e. with Neighbor.Init().
  • ltype (int) –

    The type of selection to get:

    EDGESELECTIONTYPE_SELECTION Edge selection.
    EDGESELECTIONTYPE_HIDDEN Hidden edges.
    EDGESELECTIONTYPE_PHONG Phong edges.
Return type:

c4d.BaseSelect

Returns:

The selected edges.

PolygonObject.SetSelectedEdges(e, pSel, ltype)

Set the selected, hidden or phong break edges. The edges are indexed uniquely by a Neighbor object, so each edge has a single index.

Note

This is a convenience wrapper around GetEdgeS(), GetEdgeH() and GetPhongBreak().

Parameters:
  • e (c4d.utils.Neighbor) – The neighbor object with information about the edge topology. Must be initialized with all polygons, i.e. with Neighbor.Init().
  • pSel (c4d.BaseSelect) – The edge to select.
  • ltype (int) –

    The type of selection to get:

    EDGESELECTIONTYPE_SELECTION Edge selection.
    EDGESELECTIONTYPE_HIDDEN Hidden edges.
    EDGESELECTIONTYPE_PHONG Phong edges.
Return type:

bool

Returns:

True if the selection succeeded, otherwise False.

PolygonObject.GetNgonCount()

Get the number of N-gons in the object, i.e. the number of polygons with more points than 4.

Return type:int
Returns:The number of N-gons for this object.
PolygonObject.GetSelectedNgons(sel)

Copies the current N-gon selection into sel.

Parameters:sel (c4d.BaseSelect) – Assigned the current N-gon selection.
PolygonObject.GetHiddenNgons(sel)

Copies the current hidden N-gon selection into sel.

Parameters:sel (c4d.BaseSelect) – Assigned the current hidden N-gon selection.
PolygonObject.ValidateEdgeSelection(sel)

Deselects all selected edges in sel that are N-gon edges.

Parameters:sel (c4d.BaseSelect) – The selection to check for N-gon edges.
Return type:bool
Returns:True if successful, otherwise False.
PolygonObject.GetEdgeSelection(sel, type)

Deselects all edges in ‘sel’ that are N-gon edges as specified by type.

Parameters:
  • sel (c4d.BaseSelect) – The selection to check for N-gon edges.
  • type (int) –

    The type of selection to check:

    EDGESELECTIONTYPE_SELECTION Edge selection.
    EDGESELECTIONTYPE_HIDDEN Hidden edges.
    EDGESELECTIONTYPE_PHONG Phong edges.
Return type:

bool

Returns:

True if successful, otherwise False.

PolygonObject.GetNgonEdgesCompact()
Retrieves a list that contains N-gon edges information for each polygon.

The edge compact value is based on the mask 1 << edgeIndex with edgeIndex between 1 and 4.
If the value for a polygon is zero then it has no N-gon edge.
Otherwise check each edge of the polygon with edges[polyIndex] & (1 << edgeIndex) == 0 (edges is the list of N-gon edges compact values). If the condition is True then the edge is a N-gon edge .
Return type:list
Returns:N-gon edges information list.
PolygonObject.GetShadingBreak(includeBorderEdges, includeUserBreak, includeUserNormals[, userNormalsAngle=DegToRad(5.0), autoNormalsAngle=DegToRad(180.0)])

New in version R19.

Gets the shading break edges based on neighbor polygons shading edges and a specified angle limit.

Border edges can optionally be marked as break edges.
Current break edges can optionally be included (merged) in the resulting break edges.
Finally, user normal vectors can optionally be considered using a separate angle limit for this purpose.

Note

The edges are indexed by 4 * polygon + edge where polygon is the polygon index and edge is the edge index between 0 and 3.

Parameters:
  • includeBorderEdges (bool) – True to mark border edges as break edges, otherwise False.
  • includeUserBreak (bool) – True to include the user break edges (same as obtained with GetPhongBreak()), otherwise False.
  • includeUserNormals (bool) – True to consider user normals using the userNormalAngle parameter, otherwise False.
  • userNormalsAngle (float) – Optional angle limit, in radians, beyond which polygon vertex normals sharing edge vertices create a break edge.
  • autoNormalsAngle (float) – Optional angle limit, in radians, beyond which polygon normals sharing an edge create a break edge.
Return type:

c4d.BaseSelect

Returns:

The shading break edges.

Polygon Object in Detail

../../../../../../../../_images/main.jpg

A polygon is a triangle or a quadrangle. A triangle has the points A, B and C, a quadrangle has the points A, B, C, and D.

A perfect polygon

Perfect polygons, like the one in the image above, are not that common, since the points may lie anywhere in 3D space. This is not a problem if the points are planar - i.e. if they all lie on the same plane as in the next image.

A planar quadrangle

If the quadrangle’s points are not on the same plane, the quadrangle is said to be non-planar. In the next image, point B has been moved into the depth plane. Now, Cinema 4D must render this polygon as two triangles. This happens internally and usually has no negative effects. However, non-planar polygons can occasionally lead to unexpected effects and are generally best avoided.

Point B moved into depth - non planaer

For planar quadrangles, if the interior angle at points B or D is greater than 180°, problems can occur when rendering - this is because the polygon overlaps itself as in the next image.

Angle at point B is greater than 180 - the polygon overlaps

Another problem arises if all the polygon’s points are on the same line. In this case, a surface normal cannot exist and the polygon is called a degenerated polygon, illustrated in the next image:

All points are on the same line

Polygon coordinate system

Polygons in Cinema 4D have their own coordinate system. You cannot see this system in the viewports, but it is important to be aware of it when using modeling tools.

The origin of the polygon coordinate system is located at the center of the polygons. The X axis is along the line between A and B. The Z axis is the normal. The Y axis is perpendicular to the XZ plane.

Polygons in Cinema 4D have their own coordinate system

N-gons

../../../../../../../../_images/001353.jpg

An N-gon (pronounced en-gon) is simply a polygon that has more than four corner points. N-gons can help to simplify the polygon modeling process.

Before n-gons were implemented in Cinema 4D, almost every time you cut a polygon, new edges would be created automatically on the neighboring polygons. These extra edges could make the object difficult to work with and slow down your workflow, because a manual rebuilding would often be required in order to cleanup the mesh.

The following example demonstrates the advantage of using n-gons.

../../../../../../../../_images/001354.jpg