CL_stela_area

Description

CL_stela_area computes the projected area of an object perpendicularly to a given direction.

Three modes are possible: "tumb" (tumbling mode), "spin" (spinning mode) and "fix" (fixed direction). In "fixed" mode, additional rotations of one or more sub-parts can be defined via the rotdesc input parameter

The rotdesc input parameter allowing the definition of rotations of sub-parts rotations is a list of structures, each structure containing the following fields:

- id: (string) Name of sub-part.

- axis: Rotation axis in object's frame. (3xN or 3x1)

- ang: Rotation angle (rad). (1xN or 3x1)

- rcen: (optional) Rotation center in sub-part's frame. (origin of frame = reference position of sub-part). Default = [0;0;0]. (3xN or 3x1)

The opt structure contains the (optional) following fields:

- resol: (integer, optional) Resolution (total number of "pixels"). Default is 10000. (1x1)

- savePrefix: (string, optional) Begining of path of saved XML files. Default is "" (no file saved). (1x1)

Parameters

desc:

(string or struct) Path of XML file or object description in Scilab form.

direction:

Projection direction in object frame. (3xN or 3x1)

nbp:

(integer) Number of projection planes for tumbling or spinning modes. (1x1)

axis:

Rotation axis (for spinning mode). (3xN or 3x1)

rotdesc:

(list) List of structures describing rotations of sub-parts.

opts:

(struct) Option structure.

Authors

• CNES - DCT/SB

See also

• CL_stela_objLoad

Examples

// XML description desc = fullfile(CLx_setting_get("STELA_ROOT"), "examples/example_shap.xml"); opts = struct("resol", 10000); // Example 1 (no rotations of sub-parts) alpha = linspace(0, 2*%pi, 10); direction = [cos(alpha); zeros(alpha); sin(alpha)]; area = CL_stela_area(desc, "fix", direction, opts); // Example 2 (with rotations of sub-parts) alpha = linspace(0, 2*%pi, 10); direction = [0;0;1]; rotdesc = list(struct("id", "GS +Y1", "axis", [0;1;0], "ang", alpha)); area = CL_stela_area(desc, "fixr", direction, rotdesc, opts); // Example 3 (argument = object structure) alpha = linspace(0, 2*%pi, 10); direction = [cos(alpha); zeros(alpha); sin(alpha)]; obj = CL_stela_objLoad(desc); area = CL_stela_area(obj, "fix", direction, opts);