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This is the verlet Reference Manual, version 0.0.8, generated automatically by Declt version 4.0 beta 2 "William Riker" on Thu Sep 15 06:29:04 2022 GMT+0.
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[macro] DEFORCE NAME MODE (&REST LAMBDA-LIST) &BODY BODY
Define a force so it is usable in the BUILD-SYSTEM macro.
MODE is required to be one of :FORCE, :VELOCITY-DEPENDENT-FORCE, :CONSTRAINT,
and :COLLISION. Reference the STEP! function for more information on what these
mean.
The LAMBDA-LIST is tha lambda list used by the local macro in the BUILD-SYSTEM
macro call, BODY is it's body. The resulting code should return the object to
add to the system under construction. PARTICLES is an anaphoric variable in the
BODY, containing a list of the particles defined by PARTICLES in the
BUILD-SYSTEM macro, in the order they are defined in.
[macro] BUILD-SYSTEM (&REST PARTICLES) &BODY FORCES
Build up a standard physics SYSTEM using defined forces.
PARTICLES is a list with items of the form
((X Y Z) &KEY (MASS 1.0) PREVIOUS-POSITION VELOCITY).
The list at the beginning describes the position of the particle, for the
meaning of the keyword arguments reference the [PARTICLE] function.
FORCES is a list of force descriptors, as defined by the DEFORCE macro. The
respective forces are going to be added to the final system.
[function] STEP! SYSTEM DELTA &KEY (RESOLVE-STEPS 1)
Updates a physical SYSTEM by timestep DELTA.
Apply all forces not dependent on the velocity of particles (:FORCE in the
DEFORCE macro)
Calculate forces depending on velocities of particles, using the memoized
velocities so far (:VELOCITY-DEPENDENT-FORCE in the DEFORCE macro)
Repeat RESOLVE-STEPS times:
Resolve all static constraints (:CONSTRAINT in the DEFORCE macro)
Resolve collisions (:COLLISION in the DEFORCE macro)
Please note after STEP! returns, no collisions should be happening, but static
constraints might be violated.
[function] [PARTICLE] POSITION &KEY (MASS 1.0) PREVIOUS-POSITION VELOCITY
Returns an instance of class PARTICLE at POSITION. Provide only one keyword
argument among PREVIOUS-POSITION and VELOCITY, since the respective other is
calculated from the provided. If none are provided, assume a velocity of 0.
[function] VELOCITY<- PARTICLE
Return the velocity of PARTICLE as a (SIMPLE-ARRAY SINGLE-FLOAT (3)).
Please note that this is a best guess at the current velocity, based on the forces applied so far in the current frame.
[function] SPEED<- PARTICLE
Return the speed of PARTICLE as a SINGLE-FLOAT.
Please note that this is a best guess at the current speed, based on the forces applied so far in the current frame.
[function] DEFLECT! PARTICLE DIRECTION
Moves PARTICLE to TARGET and mirrors the PARTICLE's velocity on the plane
containing TARGET with the change in position as normal.
[method] UPDATE! (PARTICLE PARTICLE)
Move PARTICLE by DELTA times the PARTICLEs velocity.
[function] [SPRING] P1 P2 K &KEY (LENGTH (RTG-MATH.VECTOR3:DISTANCE (POSITION<- P1) (POSITION<- P2)))
Create a SPRING connecting the PARTICLEs P1 and P2, with ideal
length LENGTH and spring constant K. LENGTH defaults to the distance between P1
and P2.
[method] UPDATE! (OBJECT SPRING)
Exert a length-restoring force on the endpoints of the linear spring.
Area springs are hard to predict and may be buggy in unknown ways. Combining them with standard or volume springs seems to violato conservation of momentum.
[function] [AREA-SPRING] P1 P2 P3 K &KEY (AREA (/ (RTG-MATH.VECTOR3:LENGTH (RTG-MATH.VECTOR3:CROSS (RTG-MATH.VECTOR3:- (POSITION<- P1) (POSITION<- P2)) (RTG-MATH.VECTOR3:- (POSITION<- P1) (POSITION<- P3)))) 2.0))
Creates an AREA-SPRING with corners P1, P2 and P3, ideal area AREA, and
spring constant K. AREA defaults to the area enclosed by the supplied
particles.
[method] UPDATE! (OBJECT AREA-SPRING)
Exert an area-restoring force on the corners of the area spring
Volume springs are hard to predict and may be buggy in unknown ways. Combining them with standard or area springs seems to violate conservation of momentum.
[function] [VOLUME-SPRING] P1 P2 P3 P4 K &KEY (VOLUME (ABS (/ (RTG-MATH.VECTOR3:DOT (RTG-MATH.VECTOR3:- (POSITION<- P4) (POSITION<- P1)) (RTG-MATH.VECTOR3:CROSS (RTG-MATH.VECTOR3:- (POSITION<- P3) (POSITION<- P1)) (RTG-MATH.VECTOR3:- (POSITION<- P2) (POSITION<- P1)))) 6)))
Create a VOLUME-SPRING with corners P1, P2, P3 and P4, ideal volume VOLUME,
and spring constant K. VOLUME defaults to the volume enclosed by the given
particles.
[method] UPDATE! (OBJECT VOLUME-SPRING)
Exert a volume-restoring force on the corners of the volume spring.
[class] MODIFICATOR
MODIFICATOR objects keep track of other objects to modify in a uniform
fashion. The MODIFICATOR class itself is not meant to be instanciated. An
inheriting class should implement a method for UPDATE! to make use of its
subjects.
[generic-function] ADD-SUBJECT MODIFICATOR SUBJECT
Adds a SUBJECT to the MODIFICATOR for tracking.
[generic-function] REMOVE-SUBJECT MODIFICATOR SUBJECT
Remove a SUBJECT to the MODIFICATOR so it won't be tracked anymore.
[function] [GLOBAL-GRAVITY] GRAVITY
Creates an instance of GLOBAL-GRAVITY which accelerates all its
subjects by GRAVITY on each frame.
[method] UPDATE! (GRAVITY GLOBAL-GRAVITY)
Accelerate the subjects of GRAVITY by the gravity vector.
[class] MUTUAL-GRAVITY MODIFICATOR
Applies gravitational force to the tracked particles according to the mass of the other tracked particles.
[function] [FIELD-GRAVITY] FIELD
Creates FIELD-GRAVITY with gravity field FIELD. FIELD must map
positions (SIMPLE-ARRAY SINGLE-FLOAT (3))s to gravity vectors
(SIMPLE-ARRAY SINGLE-FLOAT (3)).
[generic-function] VIOLATED? CONSTRAINT PARTICLE
Returns NIL when the constraint is fulfilled and a truthy value
otherwise.
[generic-function] DEFLECTION-VECTOR CONSTRAINT PARTICLE
Returns the cange in position for PARTICLE to obey CONSTRAINT again.
[method] UPDATE! (CONSTRAINT CONSTRAINT)
Deflects all subjects violating the constraint as per VIOLATED? by the vector
defined by DEFLECTION-VECTOR.
[function] [PLANE-CONSTRAINT] POINT NORMAL
Creates a PLANE-CONSTRAINT restricting all subjects to a half-space
defined by the plane containing POINT with normal NORMAL. The usable half-space
is the closed half-space that NORMAL is pointing into.
[function] [SPHERE-CONSTRAINT] CENTER RADIUS &OPTIONAL OUTER-WALL?
Creates a SPHERE-CONSTRAINT with center CENTER and radius
RADIUS. CENTER is a (SIMPLE-ARRAY SINGLE-FLOAT (3)), RADIUS a
SINGLE-FLOAT. When OUTER-WALL? is truthy, movement is restricted to the closed
ball described by the sphere, otherwise movement is constricted to the outside
of the open ball described by the sphere.
[function] [TRIANGLE-CONSTRAINT] P1 P2 P3
Create a TRIANGLE-CONSTRAINT preventing particles moving through the
triangle enclosed by P1, P2, and P3
[function] FRICTION! PARTICLE FRICTION DELTA
Reduce the speed of PARTICLE by FRICTION·DELTA to a minimum of speed 0. This
means that the PARTICLE's velocity's direction is never reversed by this
function. Modifies PARTICLE.
[method] UPDATE! (OBJECT GLOBAL-FRICTION)
Apply the global friction to all subjects.
[function] [FIELD-FRICTION] FIELD
Creates FIELD-FRICTION with friction field FIELD. FIELD must map 3D
positions to friction values.
[function] [CONSTRAINT-FRICTION] CONSTRAINT FRICTION
Creates CONSTRAINT-FRICTION which applies friction FRICTION to subjects on
collision with CONSTRAINT. Note that the subject of the CONSTRAINT-FRICTION
instance and of the constraint need not necessarily be the same.
Next: Modules, Previous: Introduction, Up: The verlet Reference Manual [Contents][Index]
The main system appears first, followed by any subsystem dependency.
Verlet is a simple physics engine based on verlet
integration. It supports particles with position and direction, springs
between particles, global gravity as well as gravity between particles, and
spacial constraints.
Thomas Bartscher <thomas-bartscher@weltraumschlangen.de>
BSD-3
0.0.8
Next: Files, Previous: Systems, Up: The verlet Reference Manual [Contents][Index]
Modules are listed depth-first from the system components tree.
Next: verlet/source, Previous: Modules, Up: Modules [Contents][Index]
package.lisp (file).
verlet (system).
Next: verlet/source/spring, Previous: verlet/utility, Up: Modules [Contents][Index]
verlet (system).
Next: verlet/source/gravity, Previous: verlet/source, Up: Modules [Contents][Index]
source (module).
Next: verlet/source/constraint, Previous: verlet/source/spring, Up: Modules [Contents][Index]
source (module).
Next: verlet/source/friction, Previous: verlet/source/gravity, Up: Modules [Contents][Index]
source (module).
Previous: verlet/source/constraint, Up: Modules [Contents][Index]
source (module).
Next: Packages, Previous: Modules, Up: The verlet Reference Manual [Contents][Index]
Files are sorted by type and then listed depth-first from the systems components trees.
Next: verlet/package.lisp, Previous: Lisp, Up: Lisp [Contents][Index]
verlet (system).
Next: verlet/utility/algebra.lisp, Previous: verlet/verlet.asd, Up: Lisp [Contents][Index]
verlet (system).
Next: verlet/utility/set.lisp, Previous: verlet/package.lisp, Up: Lisp [Contents][Index]
utility (module).
Next: verlet/source/force.lisp, Previous: verlet/utility/algebra.lisp, Up: Lisp [Contents][Index]
Next: verlet/source/particle.lisp, Previous: verlet/utility/set.lisp, Up: Lisp [Contents][Index]
source (module).
Next: verlet/source/physics-loop.lisp, Previous: verlet/source/force.lisp, Up: Lisp [Contents][Index]
source (module).
Next: verlet/source/spring/linear.lisp, Previous: verlet/source/particle.lisp, Up: Lisp [Contents][Index]
force.lisp (file).
source (module).
Next: verlet/source/spring/area.lisp, Previous: verlet/source/physics-loop.lisp, Up: Lisp [Contents][Index]
spring (module).
Next: verlet/source/spring/volume.lisp, Previous: verlet/source/spring/linear.lisp, Up: Lisp [Contents][Index]
spring (module).
Next: verlet/source/spring/force.lisp, Previous: verlet/source/spring/area.lisp, Up: Lisp [Contents][Index]
spring (module).
Next: verlet/source/modificator.lisp, Previous: verlet/source/spring/volume.lisp, Up: Lisp [Contents][Index]
spring (module).
Next: verlet/source/damper.lisp, Previous: verlet/source/spring/force.lisp, Up: Lisp [Contents][Index]
particle.lisp (file).
source (module).
Next: verlet/source/gravity/gravity.lisp, Previous: verlet/source/modificator.lisp, Up: Lisp [Contents][Index]
source (module).
Next: verlet/source/gravity/global.lisp, Previous: verlet/source/damper.lisp, Up: Lisp [Contents][Index]
Next: verlet/source/gravity/mutual.lisp, Previous: verlet/source/gravity/gravity.lisp, Up: Lisp [Contents][Index]
gravity (module).
Next: verlet/source/gravity/field.lisp, Previous: verlet/source/gravity/global.lisp, Up: Lisp [Contents][Index]
gravity (module).
Next: verlet/source/constraint/constraint.lisp, Previous: verlet/source/gravity/mutual.lisp, Up: Lisp [Contents][Index]
gravity (module).
Next: verlet/source/constraint/plane.lisp, Previous: verlet/source/gravity/field.lisp, Up: Lisp [Contents][Index]
constraint (module).
Next: verlet/source/constraint/sphere.lisp, Previous: verlet/source/constraint/constraint.lisp, Up: Lisp [Contents][Index]
constraint.lisp (file).
constraint (module).
Next: verlet/source/constraint/triangle.lisp, Previous: verlet/source/constraint/plane.lisp, Up: Lisp [Contents][Index]
constraint.lisp (file).
constraint (module).
Next: verlet/source/friction/friction.lisp, Previous: verlet/source/constraint/sphere.lisp, Up: Lisp [Contents][Index]
constraint.lisp (file).
constraint (module).
Next: verlet/source/friction/global.lisp, Previous: verlet/source/constraint/triangle.lisp, Up: Lisp [Contents][Index]
friction (module).
Next: verlet/source/friction/field.lisp, Previous: verlet/source/friction/friction.lisp, Up: Lisp [Contents][Index]
friction.lisp (file).
friction (module).
Next: verlet/source/friction/constraint.lisp, Previous: verlet/source/friction/global.lisp, Up: Lisp [Contents][Index]
friction.lisp (file).
friction (module).
Previous: verlet/source/friction/field.lisp, Up: Lisp [Contents][Index]
friction.lisp (file).
friction (module).
constraint<- (reader method).
Next: Definitions, Previous: Files, Up: The verlet Reference Manual [Contents][Index]
Packages are listed by definition order.
Next: Indexes, Previous: Packages, Up: The verlet Reference Manual [Contents][Index]
Definitions are sorted by export status, category, package, and then by lexicographic order.
Next: Internals, Previous: Definitions, Up: Definitions [Contents][Index]
Next: Macros, Previous: Public Interface, Up: Public Interface [Contents][Index]
Next: Ordinary functions, Previous: Special variables, Up: Public Interface [Contents][Index]
Build up a standard physics SYSTEM using defined forces.
PARTICLES is a list with items of the form
‘((X Y Z) &KEY (MASS 1.0) PREVIOUS-POSITION VELOCITY)‘.
The list at the beginning describes the position of the particle, for the
meaning of the keyword arguments reference the ‘[PARTICLE]‘ function.
FORCES is a list of force descriptors, as defined by the DEFORCE macro. The respective forces are going to be added to the final system.
Define a force so it is usable in the BUILD-SYSTEM macro.
MODE is required to be one of :FORCE, :VELOCITY-DEPENDENT-FORCE, :CONSTRAINT,
and :COLLISION. Reference the STEP! function for more information on what these
mean.
The LAMBDA-LIST is tha lambda list used by the local macro in the BUILD-SYSTEM macro call, BODY is it’s body. The resulting code should return the object to add to the system under construction. PARTICLES is an anaphoric variable in the BODY, containing a list of the particles defined by PARTICLES in the BUILD-SYSTEM macro, in the order they are defined in.
Next: Generic functions, Previous: Macros, Up: Public Interface [Contents][Index]
Creates an AREA-SPRING with corners P1, P2 and P3, ideal area AREA, and spring constant K. AREA defaults to the area enclosed by the supplied particles.
Creates CONSTRAINT-FRICTION which applies friction FRICTION to subjects on collision with CONSTRAINT. Note that the subject of the CONSTRAINT-FRICTION instance and of the constraint need not necessarily be the same.
Creates [FIELD-FRICTION][class] with friction field FIELD. FIELD must map 3D positions to friction values.
Creates [FIELD-GRAVITY][class] with gravity field FIELD. FIELD must map positions ‘(SIMPLE-ARRAY SINGLE-FLOAT (3))‘s to gravity vectors ‘(SIMPLE-ARRAY SINGLE-FLOAT (3))‘.
Creates an instance of [GLOBAL-GRAVITY][class] which accelerates all its subjects by GRAVITY on each frame.
Returns an instance of class PARTICLE at POSITION. Provide only one keyword argument among PREVIOUS-POSITION and VELOCITY, since the respective other is calculated from the provided. If none are provided, assume a velocity of 0.
Creates a [PLANE-CONSTRAINT][class] restricting all subjects to a half-space defined by the plane containing POINT with normal NORMAL. The usable half-space is the closed half-space that NORMAL is pointing into.
Creates a [SPHERE-CONSTRAINT][class] with center CENTER and radius
RADIUS. CENTER is a ‘(SIMPLE-ARRAY SINGLE-FLOAT (3))‘, RADIUS a
SINGLE-FLOAT. When OUTER-WALL? is truthy, movement is restricted to the closed
ball described by the sphere, otherwise movement is constricted to the outside
of the open ball described by the sphere.
Create a [SPRING][class] connecting the ‘PARTICLE‘s P1 and P2, with ideal length LENGTH and spring constant K. LENGTH defaults to the distance between P1 and P2.
Create a [TRIANGLE-CONSTRAINT][class] preventing particles moving through the triangle enclosed by P1, P2, and P3
Create a VOLUME-SPRING with corners P1, P2, P3 and P4, ideal volume VOLUME, and spring constant K. VOLUME defaults to the volume enclosed by the given particles.
Moves PARTICLE to TARGET and mirrors the PARTICLE’s velocity on the plane containing TARGET with the change in position as normal.
Reduce the speed of PARTICLE by FRICTION·DELTA to a minimum of speed 0. This means that the PARTICLE’s velocity’s direction is never reversed by this function. Modifies PARTICLE.
Return the speed of PARTICLE as a SINGLE-FLOAT.
Please note that this is a best guess at the current speed, based on the forces applied so far in the current frame.
Updates a physical SYSTEM by timestep DELTA.
1. Apply all forces not dependent on the velocity of particles (:FORCE in the
DEFORCE macro)
2. Calculate forces depending on velocities of particles, using the memoized
velocities so far (:VELOCITY-DEPENDENT-FORCE in the DEFORCE macro)
3. Repeat RESOLVE-STEPS times:
1. Resolve all static constraints (:CONSTRAINT in the DEFORCE macro)
2. Resolve collisions (:COLLISION in the DEFORCE macro)
Please note after STEP! returns, no collisions should be happening, but static constraints might be violated.
Return the velocity of PARTICLE as a ‘(SIMPLE-ARRAY SINGLE-FLOAT (3))‘.
Please note that this is a best guess at the current velocity, based on the forces applied so far in the current frame.
Next: Standalone methods, Previous: Ordinary functions, Up: Public Interface [Contents][Index]
Adds a SUBJECT to the MODIFICATOR for tracking.
automatically generated reader method
automatically generated writer method
Returns the cange in position for PARTICLE to obey CONSTRAINT again.
automatically generated reader method
automatically generated reader method
automatically generated writer method
automatically generated writer method
automatically generated reader method
automatically generated reader method
automatically generated writer method
automatically generated writer method
automatically generated reader method
%k.
automatically generated reader method
automatically generated writer method
%k.
automatically generated writer method
Remove a SUBJECT to the MODIFICATOR so it won’t be tracked anymore.
Apply the global friction to all subjects.
Deflects all subjects violating the constraint as per VIOLATED? by the vector defined by DEFLECTION-VECTOR.
Accelerate the subjects of GRAVITY by the gravity vector.
Exert a volume-restoring force on the corners of the volume spring.
Exert an area-restoring force on the corners of the area spring
Returns NIL when the constraint is fulfilled and a truthy value otherwise.
automatically generated reader method
automatically generated writer method
Next: Classes, Previous: Generic functions, Up: Public Interface [Contents][Index]
Previous: Standalone methods, Up: Public Interface [Contents][Index]
(function ((simple-array single-float (3))) (single-float 0.0))
:field
(function ((simple-array single-float (3))) (simple-array single-float (3)))
:field
(single-float (0.0))
:friction
(simple-array single-float (3))
:gravity
MODIFICATOR objects keep track of other objects to modify in a uniform fashion. The MODIFICATOR class itself is not meant to be instanciated. An inheriting class should implement a method for UPDATE! to make use of its subjects.
fset:set
(fset:set)
Applies gravitational force to the tracked particles according to the mass of the other tracked particles.
(simple-array single-float (3))
:position
(simple-array single-float (3))
(rtg-math.base-vectors:v! 0 0 0)
(simple-array single-float (3))
(rtg-math.base-vectors:v! 0 0 0)
(simple-array single-float (3))
:previous-position
(real (0))
1.0
(simple-array single-float (3))
:actual-previous-position
(single-float (0.0))
:mass
(simple-array single-float (3))
:point
This slot is read-only.
(simple-array single-float (3))
:center
This slot is read-only.
(single-float (0.0))
:radius
This slot is read-only.
boolean
:outer-wall?
This slot is read-only.
(single-float 0.0)
:length
fset:set
(fset:set)
fset:set
(fset:set)
fset:set
(fset:set)
fset:set
(fset:set)
fset:set
(fset:set)
Previous: Public Interface, Up: Definitions [Contents][Index]
Next: Generic functions, Previous: Internals, Up: Internals [Contents][Index]
Previous: Ordinary functions, Up: Internals [Contents][Index]
automatically generated reader method
automatically generated reader method
automatically generated reader method
automatically generated writer method
automatically generated reader method
automatically generated reader method
automatically generated reader method
%p1.
automatically generated reader method
%p1.
automatically generated reader method
automatically generated reader method
%p2.
automatically generated reader method
%p2.
automatically generated reader method
automatically generated reader method
%p3.
automatically generated reader method
%p3.
automatically generated reader method
automatically generated reader method
%p4.
automatically generated reader method
automatically generated reader method
automatically generated reader method
automatically generated writer method
Previous: Definitions, Up: The verlet Reference Manual [Contents][Index]
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