The splinepool input of the ExpressionME-L Node allows for programmatic access to Spline objects (Shape Objects) in 3ds Max. You can use various functions to create highly optimized thinkingParticle Splines. Nearly every aspect of a spleane generation can be accessed/modified. This can be useful for creating a wide range of visual effects that involve splines.
The purpose of this function is to create thinkingParticles splines based on particles in a simulation. If this function is called without any parameters, it will create an empty spline that is ready to have knots added to it. The function also enables the user to set the spline type to one of the following: Bzier Curve (spline), Corner, or Automatic.
Calls:
//create a new empty spline
//return is either -1 for fail, or the newly created spline_id
spline_id = splinepool_in_spline();
//create a spline with a defined spline id
splinepool_in_spline(in_spline_id);
//add a knot particle id at the end of a spline
splinepool_in_spline(in_spline_id, in_add_pid);
//add a knot particle id and set the knot type to corner. Knot types are:
// 1) knot_type_auto (default) 2) knot_type_corner 3)knot_type_spline
splinepool_in_spline(in_spline_id, in_add_pid, knot_type_corner);
//add a knot particle id at a specific position on the spline, index starts at 0
//spline knots can created in random order, sorting will be automatic smallest to largest
splinepool_in_spline(in_spline_id, in_add_pid, in_knot_type, in_knot_id);
Parameters:
| Parameter | Description |
|---|---|
| empty | splinepool_in_spline() will create an empty spline |
| in_spline_id | supply a spline id to create or add a knot |
| in_add_pid | knot particle index to add to the spline, a particle can only exist at one spline |
| in_knot_type | knot type (see table below) |
| in_knot_insert_id | knot sort id, for random order insert. This lets you specify an order to insert a knot. Usually knots are automatically added at the end of the spline! |
knot_types
| Parameter | Description |
|---|---|
| knot_type_corner | creates a corner knot type (straight line) |
| knot_type_spline | creates a bezier spline type |
| knot_type_auto | creates an automatic type of spline (smooth) |
Output:
| Return | Description |
|---|---|
| scalar | -1: failed, success returnes the newly created spline ID |
This function is used to create a branch from an existing spline knot (particle) and extend the spline length. The function automatically snaps the first branch knot to the particle position of the existing spline knot and creates a new spline (branch) to start with. Tracking the branching knot will be automatically performed by the spline function. The function also allows the user to retrieve the ID of the last spline that was created by a previous call to this function. Adding knots to a branch is identical to the method described above (splinepool_in_spline()), and spline knots are automatically added based on new particle positions.
Calls:
//add an empty branch spline on a knot particle
//this function returns the new branch spline index or -1 when failed (particle is not a knot)
spline_id = splinepool_in_branch(in_knot_pid);
//this function creates a branch and sets the first knot at the same time
//this function returns the new branch spline index or -1 when faild
//the first branch knot particle will automatically be snapped and tracked to the in_knot_pid
spline_id = splinepool_in_branch(in_knot_pid, in_add_pid);
//same function as above, in addition you can specify the knot type
spline_id = splinepool_in_branch(in_knot_pid, in_add_pid, in_knot_type);
Parameters:
| Parameter | Description |
|---|---|
| in_knot_pid | the particle index of a spline knot to add a branch (start a new spline) |
| in_add_pid | the first knot particle to start a branch, will be snapped and tracked to the in_knot_pid |
| in_knot_type | the knot type of the in_add_pid |
Output:
| Return | Description |
|---|---|
| scalar | -1: failed, success: returns the branch spline id, to add additional knots use the splinepool_in_spline function. |
This function is used to retrieve various information related to the splines created using the splinepool system. This function can be used to get the total number of splines, the total number of knots, the ID of the spline associated with a particle, the ID of the last created spline, the ID of the last created knot, the ID of the last knot, the lead particle (the particle to draw the spline to), the knot type, the length of the spline (either total including branch or the individual spline), UVW coordinate at the knot of the spline, and the vertex color of the knot.
Calls:
//get the total number of splines in the pool (including branches)
numberofsplines = splinepool_get(spool_nsplines)
//get the last created spline id
spline_id = splinepool_get(spool_sid);
//get the last created knot id
knot_id = splinepool_get(spool_kid);
//get spline length in absolute generic coordinates
length = splinepool_in_get(spool_length, in_spline_id);
//get spline leader particle id (last particle)
pid = splinepool_in_get(spool_lead_pid, in_spline_id);
//get the number of knots in a spline
//in_spline_id is the index of the spline which falls between 0 and numberofsplines-1
numberofknots = splinepool_in_get(spool_nknots, in_spline_id);
//get knot particle id
pid = splinepool_in_get(spool_knot_pid, in_spline_id, in_knot_id);
//get knot type
knot_type = splinepool_in_get(spool_knot_type, in_spline_id, in_knot_id);
//get knot uvw if set; return 1 if set; return 0 if not set
splinepool_in_get(spool_knot_uvw, in_spline_id, in_knot_id, out_uvw[3]);
//get knot vertex color if set; return 1 if set; return 0 if not set
splinepool_in_get(spool_knot_vcol, in_spline_id, in_knot_id, out_color[3]);
//particle id to spline_id
//if the particle is a spline knot the spline id will be returned otherwise -1
spline_id = splinepool_in_get(spool_pid2spline, in_pid);
//get a interpolated world position on the spline
//in_spline_rel_pos input the relative spline position, 0 is the start and 1 is the end of spline
splinepool_in_get(spool_pos, in_spline_id, in_spline_rel_pos, out_world_pos[3]);
//get a interpolated tangent on the spline
splinepool_in_get(spool_tangent, in_spline_id, in_spline_rel_pos, out_tangent[3]);
//get a interpolated velocity on the spline
splinepool_in_get(spool_velocity, in_spline_id, in_spline_rel_pos, out_velocity[3]);
//get the knot 1D position on the spline in absolute lenght
scalar spos = splinepool_in_get(spool_knot_spos, in_spline_id, in_knot_id);
//get the knot 1D position on the spline in relative lenght, 0 to 1
scalar spos_rel = splinepool_in_get(spool_knot_rel_spos, in_spline_id, in_knot_id);
//get the knot tangent
splinepool_in_get(spool_knot_tangent, in_spline_id, in_knot_id, out_tangent[3]);
Parameters:
| Parameter | Description |
|---|---|
| spool_data_type | specify the data to get, find the possible spool_data_types in the table below |
| in_spline_id | the spline index starting from 0 up to the numberofsplines-1 |
| in_knot_id | the knot index starting from 0 up to the numberofknots-1 |
| in_pid | defines the particle index |
| out_uvw[3] | this variable (vector) stores the returned uvw coordinates |
| out_color[3] | this variable (vector) stores the returned color (R,G,B) |
| out_world_pos[3] | this variable (vector) stores the returned position |
| out_velocity[3] | this variable (vector) stores the returned velocity |
| out_tangent[3] | this variable (vector) stores the returned tangent |
spool_data types:
| Parameter | Description |
|---|---|
| spool_nsplines | number of splines in the pool |
| spool_nknots | number of knots in the spline |
| spool_length | length of a spline in generic absolute |
| spool_knot_pid | particle id of a knot |
| spool_knot_type | knot type (corner, spline or auto) |
| spool_knot_uvw | texmap uvw coordinates of the knot |
| spool_knot_vcol | vertex color of the knot |
| spool_knot_spos | retrieves a position on the spline (scalar, length) |
| spool_knot_rel_spos | retrieves realtive position on the spline (between 0-1) |
| spool_knot_tangent | retrives the tangent of the knot (orientation), returns a vector |
| spool_pid2spline | particle to spline, returns the spline id when the particle is a knot |
| spool_lead_pid | the leader partilce id of the spline |
| spool_sid | last created spline index |
| spool_kid | last created knot index |
| spool_pos | retrieves the 3D world coordinate on the spline |
| spool_out_tangent | retrieves an interpolated tangent anywhere on the spline |
| spool_out_vel | retrieves the interpolated the interpolated velocity anywhere on the spline |
Output:
| Return | Description |
|---|---|
| scalar | variable return values dependent on the spool_data_type |
This function is used to set various parameters related to the splines created using the splinepool system. This function can be used to set the lead particle, the knot type, the UVW coordinates, and the vertex color of the spline knots.
Calls:
//set the knot type
splinepool_in_set(spool_knot_type, in_spline_id, in_knot_id, in_knot_type);
//set the knot uvw
splinepool_in_set(spool_knot_uvw, in_spline_id, in_knot_id, in_uvw[3]);
//set the knot vertex color
splinepool_in_set(spool_knot_vcol, in_spline_id, in_knot_id, in_color[3]);
//set the spline leader particle
//to unset the leader particle use -1 for the in_pid
splinepool_in_set(spool_lead_pid, in_spline_id, in_pid);
Parameters:
| Parameter | Description |
|---|---|
| in_spool_data_type | param to set see table below for in_spool_data_type |
| in_spline_id | spline index |
| in_knot_id | knot index |
| in_knot_type | knot type (knot_type_corner...) |
| in_uvw[3] | texmap uvw coordinates |
| in_color[3] | color r,g,b |
in_spool_data_type:
| Parameter | Description |
|---|---|
| spool_knot_type | knot type (corner, spline or auto) |
| spool_knot_uvw | texmap uvw coordinates of the knot |
| spool_knot_vcol | vertex color of the knot |
| spool_lead_pid | the lead particle ID of the spline, to remove the lead particle use -1 |
Output:
| Return | Description |
|---|---|
| scalar | 0: failed, 1: success |
The purpose of this function is to procedruallt remove a complete spline or specific knots from a spline
Calls:
//remove all splines
splinepool_in_remove();
//remove the spline with spline_id = 0 - (nsplines-1))
splinepool_in_remove(in_spline_id);
//remove the knot on spline with spline_id = 0 - (nsplines-1)) and knot_id = 0 - nknots-1
splinepool_in_remove(in_spline_id, in_knot_id);
//to let the spline particles stay alive add a false (is the same as 0) at the end
//the full call to remove all splines and not the particles
splinepool_in_remove(-1, -1, false);
//remove the spline with spline_id = 0 - (nsplines-1))
splinepool_in_remove(in_spline_id, -1, false);
//remove the knot on spline with spline_id = 0 - (nsplines-1)) and knot_id = 0 - nknots-1
splinepool_in_remove(in_spline_id, in_knot_id, false);
Parameters:
| Parameter | Description |
|---|---|
| empty | splinepool_in_remove() will delete all splines |
| in_spline_id | supply a spline id to remove a knot from, -1 will delete all splines |
| in_knot_id | knot index to delete from the spline, -1 deletes all knots and the spline |
| in_kill_particle | true (default) will kill the knot particle, false - will keep the knot particle |
Output:
| Return | Description |
|---|---|
| scalar | 0: failed, 1: success |