oivAlgebraicShape.h File Reference

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Classes
struct	OivASRay
	Structure for parameters of the ray. More...
struct	OivASPoint
	Structure containing information about the the raycast intersection point. More...

Macros
#define	OIV_HAS_ASRAY

Functions
bool	OivASSolveQuadric (in vec3 abc, inout vec2 roots)
	Helper function to solve quadric of type -> a*x*x + b*x + c = 0.
bool	OivASRayPlaneIntersection (in OivASRay ray, in vec4 plane, inout float t)
	If 'ray' intersects 'plane', returns true and sets location of intersection in 't'.
vec4	OivASGetColor ()
	Returns the color (i.e.
float	OivASGetOpacity ()
	Returns the opacity (i.e.
bool	OivASIsOpaque ()
	Returns true if the shape is opaque (i.e.
void	OivASVertexShaderEntry ()
	[Slot] VERTEX_SHADER_ENTRY Defines actions from the vertex shader such as initialize varying parameters from vertex attribute and so on.
vec4	OivASComputeColor (in OivASPoint p)
	[Slot] COMPUTE_COLOR Returns the color of the fragment.
bool	OivASRayIntersection (in OivASRay ray, inout OivASPoint p)
	[Slot] rayIntersection Computes the intersection between ray and shape.

Macro Definition Documentation

OIV_HAS_ASRAY

#define OIV_HAS_ASRAY

Definition at line 5 of file oivAlgebraicShape.h.

Function Documentation

OivASComputeColor()

vec4 OivASComputeColor

(

in OivASPoint

p

)

[Slot] COMPUTE_COLOR Returns the color of the fragment.

Note that for shading facilities, the position, normal and color of the fragment are filled in the input parameter 'p'.

OivASGetColor()

vec4 OivASGetColor

(

)

Returns the color (i.e.

from material or vertex color) of the shape.

OivASGetOpacity()

float OivASGetOpacity

(

)

Returns the opacity (i.e.

alpha component) of the shape.

OivASIsOpaque()

bool OivASIsOpaque

(

)

Returns true if the shape is opaque (i.e.

OivASGetOpacity() == 1.0).

OivASRayIntersection()

bool OivASRayIntersection	(	in OivASRay	ray,
		inout OivASPoint	p
	)

[Slot] rayIntersection Computes the intersection between ray and shape.

• ray: ray parameters
• p: structure containing the intersection point position (if any), normal (if any) and color (if any)
• return true if there is intersection, false otherwise

Note that all positions and directions are defined in the space specified in the constructor of the SoAlgebraicShape node. The default one is the local frame coordinate centered at (0,0,0) with bounding box coordinates between -1.0 and 1.0.

For example, for a sphere, we consider in this function that the sphere has a radius of 1.0, centered at the origin.

OivASRayPlaneIntersection()

bool OivASRayPlaneIntersection	(	in OivASRay	ray,
		in vec4	plane,
		inout float	t
	)

If 'ray' intersects 'plane', returns true and sets location of intersection in 't'.

Plane is defined by four values 'xyzw', where 'xyz' is the normal vector and 'w' is the distance from the origin (i.e. the point p.w*p.xyz lies on the plane).

OivASSolveQuadric()

bool OivASSolveQuadric	(	in vec3	abc,
		inout vec2	roots
	)

Helper function to solve quadric of type -> a*x*x + b*x + c = 0.

Returns true if there are roots, stored in 'roots' vector. Note that it can be used in fragment shader only.

OivASVertexShaderEntry()

void OivASVertexShaderEntry

(

)

[Slot] VERTEX_SHADER_ENTRY Defines actions from the vertex shader such as initialize varying parameters from vertex attribute and so on.