Shape Class
This class creates collision shapes that approximate the finite volume of physical bodies and allow them to collide. Shapes are assigned to a body and are positioned in its local coordinates.
Shape Class
Members
vec3 getArea()
Returns areas of shape projections on three axes: x, y, and z.Return value
A triple of projection areas.void setBody(Body body)
Sets a body, to which the shape belongs.Arguments
- Body body - Body, to which the shape belongs.
Body getBody()
Returns the body, to which the shape belongs.Return value
Body, to which the shape belongs.void setBodyShapeTransform(mat4 transform)
Sets a transformation matrix for the shape (in the coordinates of the body). This matrix describes position and orientation of the shape. This method is identical to setShapeTransform().Arguments
- mat4 transform - Transformation matrix
mat4 getBodyShapeTransform()
Returns the transformation matrix of the shape (in the coordinates of the body). This matrix describes position and orientation of the shape. This method is identical to getShapeTransform().Return value
Transformation matrixvec3 getCenterOfMass()
Returns local coordinates of the center of mass of the shape.Return value
Coordinates of the center of mass.int getCollision(Vector<Contact>& contacts, float ifps)
Performs collision check for the shape and puts information on all contacts to the output buffer.Collisions with the surface can be found only if the following conditions are fulfilled:
- The surface is enabled.
- Per-surface Collision flag is enabled.
- The surface has a material assigned.
- A property inherited from the surface_base is assigned to the surface and the collision parameter of this property is set to 1 (e.g. via the setParameterInt() method).
Notice
The shape must be enabled.
Arguments
- Vector<Contact>& contacts - Output buffer containing information on all detected physical contacts for the shape (if any). Information on each contact can be handled via the Contact class.
- float ifps - Inverse FPS value.
Return value
1 if collisions are found; otherwise, 0.int getCollision(const Object & object, Vector<Contact>& contacts, float ifps)
Performs collision check for the shape and puts information on all contacts and contact object to the output buffer.Collisions with the surface can be found only if the following conditions are fulfilled:
- The surface is enabled.
- Per-surface Collision flag is enabled.
- The surface has a material assigned.
- A property inherited from the surface_base is assigned to the surface and the collision parameter of this property is set to 1 (e.g. via the setParameterInt() method).
Notice
The shape must be enabled.
Arguments
- const Object & object - Contact object instance.
- Vector<Contact>& contacts - Output buffer containing information on all detected physical contacts for the shape (if any). Information on each contact can be handled via the Contact class.
- float ifps - Inverse FPS value.
Return value
1 if collisions are found; otherwise, 0.void setCollisionMask(int mask)
Sets a collision mask for the shape. Two objects collide if they both have matching masks. See also details on additional collision exclusion mask.Arguments
- int mask - Integer, each bit of which is a mask.
int getCollisionMask()
Returns the collision mask of the actor. Two objects collide if they both have matching masks.See also details on additional collision exclusion mask.Return value
Integer, each bit of which is a mask.void setContinuous(int continuous)
Enables or disables continuous collision detection for spheres or capsules. Enabled CDD incurs almost no performance penalty. Disabling CCD allows to avoid physics artifacts, if there are any.Arguments
- int continuous - Positive value to enable CCD; 0 to disable.
int isContinuous()
Returns a value indicating if continuous collision detection for spheres or capsules is enabled. Enabled CCD incurs almost no performance penalty. Disabling CCD allows to avoid physics artifacts, if there are any.Return value
1 if CCD is enabled; otherwise, 0.void setDensity(float density)
Sets density of a shape. Changing the density influences the mass, that is computed by multiplying shape volume by density.Arguments
- float density - Density value. If a negative value is provided, 0 will be used instead.
float getDensity()
Returns the current density of a shape.Return value
Density value.void setEnabled(int enable)
Enables or disables physical interactions with the shape.Arguments
- int enable - Positive number to enable physical interactions, 0 to disable them.
int isEnabled()
Returns a value indicating if physical interactions with the shape are enabled.Return value
1 if physical interactions with the shape are enabled; otherwise, 0.int isEnabledSelf()
Returns a value indicating if the shape is enabled.Return value
1 if the shape is enabled; otherwise, 0.void setExclusionMask(int mask)
Sets an bit mask to prevent collisions of the shape with other ones. This mask is independent of the collision mask. For shapes with matching collision masks not to collide, at least one bit of their exclusion mask should match.Arguments
- int mask - Integer, each bit of which is a mask.
int getExclusionMask()
Returns the bit mask that prevents collisions of the shape with other ones. This mask is independent of the collision mask. For shape with matching collision masks not to collide, at least one bit of their exclusion mask should match.Return value
Integer, each bit of which is a mask.void setFriction(float friction)
Sets a friction of the shape surface.Arguments
- float friction - Friction of the shape surface. If a negative value is provided, 0 will be used instead.
float getFriction()
Returns the friction of the shape surface.Return value
Friction of the shape surface.int setID(int id)
Sets the unique ID for the shape.Arguments
- int id - Unique ID.
Return value
1 if the ID is set successfully; otherwise, 0.int getID()
Returns the unique ID of the shape.Return value
Unique ID.mat3 getInertia()
int getIntersection(Vec3 p0, Vec3 p1, PhysicsIntersectionNormal intersection)
Performs tracing from the p0 point to the p1 point to find a shape located on that line. Intersection is found only for objects with a matching mask.
Notice
World space coordinates are used for this function.
Arguments
- Vec3 p0 - Start point of the line.
- Vec3 p1 - End point of the line.
- PhysicsIntersectionNormal intersection - Intersection mask.
Return value
Reference to the first intersected shape, if found; otherwise - 0.int getIntersection(Vec3 p0, Vec3 p1, PhysicsIntersection intersection)
Performs tracing from the p0 point to the p1 point to find a shape located on that line. Intersection is found only for objects with a matching mask.
Notice
World space coordinates are used for this function.
Usage Example
The following example shows how you can get the intersection information by using the PhysicsIntersection class. In this example the line is an invisible traced line from the point of the camera (vec3 p0) to the point of the mouse pointer (vec3 p1). It is supposed that you have a shape in your world. The executing sequence is the following:
- Define and initialize two points (p0 and p1) by using the getPlayerMouseDirection() function from core/scripts/utils.h.
- Create an instance of the PhysicsIntersection class to get the information of the intersection point.
- Check, if there is a intersection with a shape and save the result in the integer variable.
- In this example, if there is an intersection of mouse direction with a specific shape called "shape", the PhysicsIntersection class instance gets the and intersection point and show the result in console.
Source code (UnigineScript)
#include <core/scripts/utils.h>
/* ... */
// define two vec3 coordinates
vec3 p0,p1;
// get the mouse direction from camera (p0) to cursor pointer (p1)
getPlayerMouseDirection(p0,p1);
// create the instance of the PhysicsIntersection object to save the information about the intersection
PhysicsIntersection intersection = new PhysicsIntersection();
// create an int varaible to check the result of intersection
int result;
result = shape2.getIntersection(p0, p1, intersection);
// if there was an intersection, show the message in console
if(result != 0)
{
log.message("intersection point: %s \n", typeinfo(intersection.getPoint()) );
}
/* ... */Arguments
- Vec3 p0 - Start point of the line.
- Vec3 p1 - End point of the line.
- PhysicsIntersection intersection - Intersection mask.
Return value
Reference to the first intersected shape, if found; otherwise - 0.int getIntersection(Vec3 p0, Vec3 p1, Vec3 ret_point, vec3 ret_normal)
Performs tracing from the p0 point to the p1 point to find a shape located on that line. Intersection is found only for objects with a matching mask.
Notice
World space coordinates are used for this function.
Arguments
- Vec3 p0 - Start point of the line.
- Vec3 p1 - End point of the line.
- Vec3 ret_point - Intersection mask.
- vec3 ret_normal - Variable defining which type of intersection object will be returned:
- PhysicsIntersection intersection — The PhysicsIntersection class instance.
- PhysicsIntersectionNormal normal — The PhysicsIntersectionNormal class instance.
Return value
Reference to the first intersected shape, if found; otherwise - 0.void setIntersectionMask(int mask)
Sets an intersection mask for the shape.Arguments
- int mask - Integer, each bit of which is a mask.
int getIntersectionMask()
Returns an intersection mask of the shape.Return value
Integer, each bit of which is a mask.void setMass(float mass)
Sets a mass of the shape. Changing the mass influences the density, that is computed by dividing the mass by shape volume.Notice
If g (Earth's gravity) equals to 9.8 m/s
2, and 1 unit equals to 1 m, a shape with mass value of
1 weighs 1 kg.
Arguments
- float mass - Mass of the shape. If a negative value is provided, 0 will be used instead.
float getMass()
Returns the mass of the shape.Notice
If g (Earth's gravity) equals to 9.8 m/s
2, and 1 unit equals to 1 m, the mass is measured in kilograms.
Return value
Mass of the shape.void setName(string name)
Sets the name of the shape.Arguments
- string name - Name of the shape.
string getName()
Returns the name of the shape.Return value
Name of the shape.int getNumber()
Returns the number of shape instances.Return value
Number of shape instances.void setRestitution(float restitution)
Sets a restitution of the shape surface.Arguments
- float restitution - Restitution of the shape surface. The provided value will be saturated in the range [0; 1].
float getRestitution()
Returns the restitution of the shape surface.Return value
Restitution of the shape surface.Shape getShape()
Returns a Shape instance.Return value
void setPosition(Vec3 position)
Sets shape position. This method resets shape's velocity to 0.Arguments
- Vec3 position - New shape's position, in world coordinates.
int isIdentity()
Returns a value indicating if the shape has a scale equal to 1 and no rotation.Return value
1 if the shape has a scale equal to 1 and no rotation; otherwise, 0.void setTransform(Mat4 transform)
Sets a transformation matrix for the shape (in world coordinates). This matrix describes position and orientation of the shape. This method resets shape's linear velocity to 0.Arguments
- Mat4 transform - Transformation matrix
Mat4 getTransform()
Returns the transformation matrix of the shape (in world coordinates). This matrix describes position and orientation of the shape.Return value
Transformation matrixint getType()
Returns the type of the shape.Return value
One of the SHAPE_* pre-defined variables.string getTypeName()
Returns the name of the shape type.Return value
Type name.string getTypeName(int type)
Returns the name of a shape type with a given ID.Arguments
- int type - Shape type ID. One of the SHAPE_* values.
Return value
Shape type name.void setVelocity(vec3 velocity, float ifps)
Sets a new velocity vector for the shape.Arguments
- vec3 velocity - Velocity vector, each component represents shape's velocity along the corresponding axis, in units per second.
- float ifps - Inverse FPS value.
vec3 getVelocity()
Returns the current velocity vector of the shape.Return value
Current celocity vector, each component represents shape's velocity along the corresponding axis, in units per second.float getVolume()
Returns the volume of the shape.Return value
Volume of the shape in cubic units.Shape clone()
Clones the shape.Return value
Copy of the shape.void renderVisualizer(vec4 color)
Renders the shape.Notice
You should enable the engine visualizer by the show_visualizer 1 console command.
Arguments
- vec4 color - Color, in which the shape will be rendered.
int restoreState(Stream stream)
Restores the state of a given node from a binary stream.- If a node is a parent for other nodes, states of these child nodes need to be restored manually.
- To save the state into a buffer, file or a message from a socket, make sure the stream is opened. If necessary, you can set a position for writing for buffers and files.
Warning
This function is deprecated and will be removed in the next release.
Arguments
- Stream stream - Stream with saved node state data.
Return value
1 if node state is successfully restored; otherwise, 0.int saveState(Stream stream)
Saves the state of a given node into a binary stream.- If a node is a parent for other nodes, states of these child nodes need to be saved manually.
- To save the state from a buffer, file or a message from a socket, make sure the stream is opened. For buffers and files, you also need to set the proper position for reading.
Warning
This function is deprecated and will be removed in the next release.
Arguments
- Stream stream - Stream to save node state data.
Return value
1 if node state is successfully saved; otherwise, 0.void swap(Shape shape)
Swaps the shapes saving the pointers.Arguments
- Shape shape - A shape to swap.
Shape createShape(int type)
Creates a new shape of the specified type.Arguments
- int type - Body type. One of the SHAPE_* values.
Return value
New created shape instance.Shape createShape(string type_name)
Creates a new shape of the specified type.Arguments
- string type_name - Shape type name.
Return value
New created shape instance.int NUM_SHAPES
int SHAPE_BOX
Description
Box.int SHAPE_CAPSULE
Description
Capsule.int SHAPE_CONVEX
Description
Convex hull.int SHAPE_CYLINDER
Description
Cylinder.int SHAPE_SPHERE
Description
Sphere.Last update: 2018-08-10
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