kunz VEX Wrangle Snippets

VEX Wrangle Snippets

From kunz
Revision as of 16:21, 4 August 2023 by Admin (talk | contribs) (→‎Plexus Effect)
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vex offset position.gif

Offset the position of geometry


@P += {1, 0, 0};


taper vex 001.gif

Reduces the circumference by scaling along the XZ plane based on the height of the geometry.


float taper = relbbox(0,@P).y;
// Remap the taper range
taper = fit01(taper, 1, fit01(sin(@Time*PI/5)*0.5+0.5, 2.5, .5));
// Apply the taper by scaling along the X and Y axis
@P *= set(taper,1,taper);


vex boxify 001.gif

Distorts the geometry, morphing it into a box shape


vector centroid = getbbox_center(0);
vector size = getbbox_size(0);
size = min(size); // Largest component
@P -= centroid;
@P *= (1.0/size);
@P = lerp(@P, @P+clamp(normalize(@P)*1.75,vector(-1),vector(1)) * (1.0-length(max(abs(@P)))), chf('blend'));
@P *= size;
@P += centroid;


vex spherify 001.gif

Distorts the geometry into a sphere shape


vector centroid = getbbox_center(0);
vector size = getbbox_size(0);
size = min(size); // Largest component
@P -= centroid;
@P *= (1.0/size);
@P = lerp(@P, normalize(@P), chf('blend'));
@P *= size;
@P += centroid;


vex stretch 001.gif

Stretch the geometry across it's X axis

Add one component of position to itself to stretch the geometry away from it's center. You can control the amount of stretching by multiplying the position before adding it to itself.


vector centroid = getbbox_center(0);
@P -= centroid;
@P.x += @P.x*chf('amt');
@P += centroid;

Shape Blending

vex position blend.gif

Blend between point attributes to produce a morph effect


@P = lerp(@P, @opinput1_P, chf('blend'));
@N = lerp(@N, @opinput1_N, chf('blend'));

Snap to Grid

vex snap to grid.gif

Snap (quantize) point positions to a grid for a downres effect


float grid_scale = chf('grid_scale');
@P = rint(@P*grid_scale)/grid_scale;

Make 2D

vex setcomp.gif

You can use the setcomp function to zero out a component of a vector, resulting in a two dimensional surface.


// Set the X component to zero, planar 2D in YZ
setcomp(@P, 0, 0);
// Set the Y component to zero, planar 2D in XZ
setcomp(@P, 0, 1);
// Set the Z component to zero, planar 2D in XY
setcomp(@P, 0, 2);

Swizzle Coordinate System

vex swizzle vector components.gif

Shuffle the components of a vector using swizzle


@P = @P.zyx;


vex twirl.gif

Twirl the geometry around the Y axis


float a = chf('angle') * length(@P * {1, 0, 1});
float u = atan2(@P.x, @P.z);
float r = length(@P * {1, 0, 1});
@P = set(sin(u-a), @P.y, cos(u-a)) * set(r,1,r);


vex push surface along normals.gif

Move the surface along it's normals, producing an inflation effect


@P += normalize(@P) * chf('scale');

Exploded View

vex exploded view.gif

Moves each packed piece outward from the geometry centroid


@P += (@P - getbbox_center(0)) * chf('scale');

Point Jitter

vex point jitter.gif

Move each point in a random direction with a spherical distribution


@P += sample_sphere_uniform(rand(@elemnum+chf('seed'))) * chf('scale');

Plexus Effect

vex plexus.gif

Connect nearby points


foreach(int pt; nearpoints(0, @P, 0.15, 10))    {
    if(pt > @ptnum)
        addprim(0, 'polyline', @ptnum, pt);

Connect to Nearest Point

Draw a line to the closest point of the second input

addprim(0, 'polyline', @ptnum, addpoint(0, vector(point(1,'P',nearpoint(1,@P)))) );

Connect to Closest Surface Position

Draw a line to the closest surface position

addprim(0, 'polyline', @ptnum, addpoint(0, minpos(1,@P) );

Randomize the Rotation of Packed Primitives

Update the transform intrinsic to a random orientation

vector r = sample_direction_uniform(rand(@primnum));
matrix3 x = primintrinsic(0,'transform',i@primnum);
rotate(x, PI*pow(rand(@primnum-666),0.5), r);

Randomize the Scale of Packed Primitives

Update the transform intrinsic to a apply a random scale

vector s = rand(i@primnum);
s = s.yyy;  // Uniform Scale
matrix3 x = primintrinsic(0,'transform',i@primnum);
scale(x, s);

Random Color from Normal Direction

Generate random colors based on the surface normal, adjust the multiplier to control the amount of colors

v@Cd = rand(rint(v@N*8));

Iterative Face Insetting

Recursive divide and inset edges, via @d_gfx, excellent use of arrays

int pts[] = primpoints(0,@primnum); vector pos[];
int edge_div_pts[]; vector edge_div_pos[];
foreach( int pt; pts ) 
    append(pos, vector(point(0,'P',pt)));
for( int i = 0; i < chi('iterations'); i++ )    {
    resize(edge_div_pts,0); // empty
    resize(edge_div_pos,0); // empty
    for( int j = 0; j < len(pts); j++ ) {
        append(edge_div_pos, lerp( pos[j], pos[(j+1)%len(pts)], chf('div_ratio') ));
        append(edge_div_pts, addpoint(0, edge_div_pos[-1])); // [-1] grabs the last item from an array
    for (int k = 0; k < len(pts); k++ ) {
        addprim(0, 'poly', pts[k], edge_div_pts[k], edge_div_pts[(k+2)%len(pts)]);
    pts = edge_div_pts;
    pos = edge_div_pos;
addprim(0, 'poly', edge_div_pts);
removeprim(0,@primnum,1); // Remove the input prim and any points belonging to it

Iridescent Color Function

vex iridescent.gif

Produce an iridescent color ramp from any varying value, from shadertoy


float amt = dot(@N, set(0,1,0))*0.5+0.5;
v@Cd =  (0.5 + 0.5 * cos( PI*2*( amt + set(0,1,2)/3) ) );

Rainbow Colors from HSV Colorspace

vex hsvtorgb rainbow 001.gif

You can easily control the hue, while keeping the saturation and value the same using the hsvtorgb function.

This allows you to easily create rainbows, gradients, perform hue rotations and produce complimentary colors.


v@Cd = hsvtorgb( set(relbbox(0,@P).z - @Time/5 + dot(@N,set(0,1,0))/2, 1, 1));

Rainbow Cycle with frac function

rainbow cycle w frac VEX.gif

Using the frac function, you can cycle through a rainbow over a desired amount of elements.

This is then offset by adding the current time to the fractional value, which produces the scrolling effect.


v@Cd = hsvtorgb(set(frac(@elemnum/8.0)+@Time/10, 1, 1));

Loop Over All Attributes

string pt_attrs[] = detailintrinsic(1,'pointattributes');
foreach( string pt_attr; pt_attrs ) {
    if( pt_attr ~= 'attr_name*' ) {
        setpointgroup(0, pt_attr, @ptnum, 1);

Remove Faces Across Bounding Box

if( relbbox(0,@P).x < rand(@primnum) )

Torus Knot

Online Knot Viewer

float u = float(@ptnum)/(@numpt-1);
u += @Time/10.0;
u %= 1.0;
u *= PI * 2;
float r = 2.0;
float q = 2;
float p = 3;
f@u = u;
@P.x += cos(u*q) * (cos(u*p)+r);
@P.y += sin(u*q) * (cos(u*p)+r);
@P.z += sin(u*p);

Remap Grid to Circle

vex map grid to circle.gif

Working with polar coordinates to map a square onto a circle.


@P += {0.5, 0.5, 0}; // Remap the grid to zero to one range
float theta = @P.x;
float radius = @P.y/2;
@P = 0;
@P.x = sin(theta*PI*2 ) * radius;
@P.y = cos(theta*PI*2 ) * radius;

Remap Grid to Sphere

vex map grid to sphere.gif

Working with polar coordinates to map a square onto a sphere.


@P += {0.5, 0.5, 0}; // Remap the grid to zero to one range
float phi = @P.x;
float theta = 1.0-@P.y;
@P.x = sin(theta*PI*1 ) * cos(phi*PI*2 )/2;
@P.z = sin(theta*PI*1 ) * sin(phi*PI*2 )/2;
@P.y = cos(theta*PI*1 )/2;

Make a Quad

int prim = addprim(0,'poly');
addvertex(0,prim,addpoint(0,set(0,0,0)) );
addvertex(0,prim,addpoint(0,set(1,0,0)) );
addvertex(0,prim,addpoint(0,set(1,0,1)) );
addvertex(0,prim,addpoint(0,set(0,0,1)) );

Make a Grid

for(int i = 0; i<8; i++)    {
    for(int j = 0; j<8; j++)    {
        int prim = addprim(0,'poly');
        addvertex(0,prim,addpoint(0,set(i,0,j)) );
        addvertex(0,prim,addpoint(0,set(i+1,0,j)) );
        addvertex(0,prim,addpoint(0,set(i+1,0,j+1)) );
        addvertex(0,prim,addpoint(0,set(i,0,j+1)) );

Make a Circle

vex make circle.gif

This example shows how you can generate a circle or N sided polygon using a for loop, sin and cos.

Run the code in detail mode with an attribute wrangle.

This is essentially the same idea as the circle node but hopefully a beneficial example to see how this type of geometry is generated via VEX.


int prim = addprim(0,'poly');
int seg = chi('segments');
for( int i = 0; i<seg; i++ )  {
    float u = float(i)/seg * 2*PI;
    addvertex(0, prim, addpoint(0, set(sin(u),0,cos(u))) );

Groups to Attribute

From zybrand

//convert numbered groups to a numbered attribute
string groups[] = detailintrinsic(0, "primitivegroups");
int prim = @primnum;
string elemnum;

foreach(string i; groups)
    //if the current primitive is in group i
    if(inprimgroup(0,i,prim) == 1)
        elemnum = re_find(r"\d{3,6}",i);
s@number = elemnum;

Looping Curl Noise

2022 12 11 looping curl noise.gif

It's possible to achieve seamless looping animation from curl noise by blending between two noises.

In this example one noise function is evaluated at the current time, and a second noise function is evaluated at the time shifted back by the desired loop duration.

The result of these two noise functions are blended from one to the other over the duration.


// Position x Frequency
vector p = @P*0.5;
// Speed
float s = 0.5;
// Loop Length (in seconds)
float l = 5;
// Time % duration
float t = (@Time%l);
// Blending
vector v0 = curlgxnoise(p + set(0,0,0,t*s));
vector v1 = curlgxnoise(p + set(0,0,0,(t-l)*s));
@P += lerp(v0,v1,frac(@Time/l)) * 0.35;