Skip to content

Commit

Permalink
Mesh primitive documentation
Browse files Browse the repository at this point in the history
  • Loading branch information
@drohmer
drohmer committed Feb 24, 2024
1 parent 43738e8 commit 58c1340
Showing 1 changed file with 116 additions and 25 deletions.
141 changes: 116 additions & 25 deletions library/cgp/11_mesh/primitive/primitive.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,59 +8,150 @@ namespace cgp
{
struct frame;

/** Generate a cylinder
* @radius: Cylinder radius
* @p0: starting point on the central axis
* @p1: ending point of the central axis
* @Nu,Nv: sampling in parametric space
* @is_closed: Is the cylinder closed at the two extremities with a disc
/** Generate a cylinder - parameterized by an axis [p0,p1] and a radius around it.
* - radius: Cylinder radius
* - p0, p1: start/end point on the central axis
* - Nu,Nv: sampling in parametric space (u=along [p0,p1], v=around the cylinder)
* - is_closed: Is the cylinder closed at the two extremities with a disc
*/
mesh mesh_primitive_cylinder(float radius=0.2f, vec3 const& p0={0,0,0}, vec3 const& p1={0,0,1}, int Nu=10, int Nv=20, bool is_closed=false);

// A simple triangle parameterized by its three points
mesh mesh_primitive_triangle(vec3 const& p0={0,0,0}, vec3 const& p1={1,0,0}, vec3 const& p2={0,1,0});

/**
* Assume the following order of position (p00,p10,p11,p01).
* p01 ----- p11
* | |
* | |
* p00 ----- p10
* Build 2 triangles: (p00,p10,p11) and (p00,p11,p01)
* uv are set such as p00:(0,0), p10:(1,0), p11:(1,1), p01:(0,1)
*/
* Build a quadrangle given by its four corner positions
*
* Assume the following order of position (p00,p10,p11,p01).
* p01 ----- p11
* | |
* | |
* p00 ----- p10
* Build 2 triangles: (p00,p10,p11) and (p00,p11,p01)
* uv are set such as p00:(0,0), p10:(1,0), p11:(1,1), p01:(0,1) */
mesh mesh_primitive_quadrangle(vec3 const& p00={0,0,0}, vec3 const& p10={1,0,0}, vec3 const& p11={1,1,0}, vec3 const& p01={0,1,0});

/** Build a planar disc parameterized by a central point, a radius, and a normal.
*
* The disc is bild by triangles that links the central point to consecutive samples along the circumference.
* - radius: the radius of the disc
* - center: the central point of the disc (an actual vertex of the mesh)
* - normal: the normal of the disc (all vertices have the same normal)
* - N: The number of sampled vertex in the circumference of the disc
* */
mesh mesh_primitive_disc(float radius=1.0f, vec3 const& center={0,0,0}, vec3 const& normal={0,0,1}, int N=40);

/** Build a sphere parameterized by a radius, and a center, sampled using a spherical coordinate parameterization
* - radius: the radius of the sphere
* - center: the position of the central point inside the sphere
* - Nu, Nv: the number of samples in the two parametric directions */
mesh mesh_primitive_sphere(float radius=1.0f, vec3 const& center={0,0,0}, int Nu=40, int Nv=20);

/** Build an ellipsoid elongated along the (x,y,z) directions.
* - scale: the elongation of the disc along x/y/z
* - center: the central point of the ellipsoid
* - Nu, Nv: the number of samples in the two parametric directions (use a spherical coordinate parameterization) */
mesh mesh_primitive_ellipsoid(vec3 scale=vec3{1.0f, 1.0f, 1.0f}, vec3 const& center={0,0,0}, int Nu=40, int Nv=20);

mesh mesh_primitive_torus(float r_major=1.0f, float r_minor=0.25f, vec3 const& center={0,0,0}, vec3 const& axis_orientation={0,0,1}, int Nu=55, int Nv=15);

/** Build a torus parameterized as
* x = (r_max + r_min * cos(theta) ) * cos(phi)
* y = (r_max + r_min * cos(theta) ) * sin(phi)
* z = r_min * sin(theta)
*
* - r_max: radius around the large revolution axis
* - r_min: radius around the smaller revolution axis
* - center: central point of the torus
* - orientation: orientation of the central axis of revolution of the torus
* - Nu, Nv: samples in the parameteric space
* */
mesh mesh_primitive_torus(float r_max=1.0f, float r_min=0.25f, vec3 const& center={0,0,0}, vec3 const& axis_orientation={0,0,1}, int Nu=55, int Nv=15);

/** Build plane sampled as a regular grid. The plane is parameterized by its 4 extremitites and the size of the sampling.
*
* p01 ----- p11
* | |
* v↑ | |
* p00 ----- p10
* -> u
*/
mesh mesh_primitive_grid(vec3 const& p00={0,0,0}, vec3 const& p10={1,0,0}, vec3 const& p11={1,1,0}, vec3 const& p01={0,1,0}, int Nu=10, int Nv=10);

/** Build cube oriented along the x/y/z direction sampled uniformly on all its faces using a regular grid.
*
* - p000, p100, p110, p010, p001, p101, p111, p011 are the corners of the cube.
*
* p011-----------p111
* /| /|
* / | / |
* p001-----------p101 |
* | | | |
* | | | |
* | p010------|---p110
* | / | /
* |/ | /
* p000---------p100
*
* - Nx, Ny, Nz: are the sampling on each of the face oriented along the x, y, and z direction
*/
mesh mesh_primitive_cubic_grid(vec3 const& p000={0,0,0}, vec3 const& p100={1,0,0}, vec3 const& p110={1,1,0}, vec3 const& p010={0,1,0}, vec3 const& p001={0,0,1}, vec3 const& p101={1,0,1}, vec3 const& p111={1,1,1}, vec3 const& p011={0,1,1}, int Nx=10, int Ny=10, int Nz=10);

/** Build a cube oriented along the x/y/z direction parameterized by a center and edge length
* Each face of the cube is made by two triangles. */
mesh mesh_primitive_cube(vec3 const& center={0,0,0}, float edge_length=1.0f);

/** Build a tetrahedron described by its three corners.*/
mesh mesh_primitive_tetrahedron(vec3 const& p0={0,0,0}, vec3 const& p1={1,0,0}, vec3 const& p2={0,1,0}, vec3 const& p3={0,0,1});



/** */
/** Build a cone
* /\ ^ height
* / \ |
* / \ |
* / \ |
* / \ | ↑: axis_direction
* / \ |
* / \ |
* /______________\ v
* |
* center_of_base
* <-------------->
* radius
*
* - radius: the radius at the base of the cylinder
* - height: the height of the cylinder along
* - center_of_base: position at the center of the base disc
* - axis_direction: direction of the central axis
* - is_closed_base: fill the base with a disc if true
* - Nu, Nv: samples along the height and radial direction
*
*/
mesh mesh_primitive_cone(float radius=0.5f, float height=1.0f, vec3 const& center_of_base={0,0,0}, vec3 const& axis_direction={0,0,1}, bool is_closed_base=true, int Nu=20, int Nv=10);

/** Mesh representing an arrow: {cylinder+cone} pointing from point p0 to point p1
* @p0: the base point of the array
* @p1: the ending point of the array
* @cylinder_radius: radius of the cylinder
* @cone_length_scale: length of cone extremity expressed as the scale of the cylinder radius
* @cone_radius_scale: radius of the cone extremity expressed as the scale of the cylinder_radius
* @N: number of samples (cylinder and cone)
* @double_sided: create an arrow also at the base point
* /\ ^
* / \ |
* / \ | cone_height_scale = ||p1-p0|| * cone_length_scale
* / \ |
* / \ |
* /____p1____\v
* | | cone_radius = cylinder_radius * cone_radius_scale
* | |
* | |
* |__| cylinder_radius
* p0
*
* p0: the base point of the array
* p1: the ending point of the array
* cylinder_radius: radius of the cylinder
* cone_height_scale: length of cone extremity expressed as the scale of the cylinder radius
* cone_radius_scale: radius of the cone extremity expressed as the scale of the cylinder_radius
* N: number of samples (cylinder and cone)
* double_sided: create an arrow also at the base point
*/
mesh mesh_primitive_arrow(vec3 const& p0={0,0,0}, vec3 const& p1={1,0,0}, float cylinder_radius=0.05f, float cone_length_scale=4.0f, float cone_radius_scale=2.5f, int N=18);
mesh mesh_primitive_arrow(vec3 const& p0={0,0,0}, vec3 const& p1={1,0,0}, float cylinder_radius=0.05f, float cone_height_scale=4.0f, float cone_radius_scale=2.5f, int N=18);

/** Build an oriented frame made of 3 orthogonal arrows to depict an x/y/z direction */
mesh mesh_primitive_frame(frame const& f=frame(), float scale=1.0f, vec3 const& color_ux={1,0,0}, vec3 const& color_uy={0,1,0}, vec3 const& color_uz={0,0,1}, vec3 const& color_sphere={1,1,1}, float frame_thickness=0.025f);
}

0 comments on commit 58c1340

Please sign in to comment.