LYGIA Shader Library

cast (lygia/lighting/raymarch/cast)

cast a ray

Dependencies:

Use:

<float> castRay( in <vec3> pos, in <vec3> nor )

Check it on Github



#ifndef RAYMARCH_SAMPLES
#define RAYMARCH_SAMPLES 64
#endif

#ifndef RAYMARCH_MIN_DIST
#define RAYMARCH_MIN_DIST 1.0
#endif

#ifndef RAYMARCH_MAX_DIST
#define RAYMARCH_MAX_DIST 20.0
#endif

#ifndef RAYMARCH_MIN_HIT_DIST
#define RAYMARCH_MIN_HIT_DIST 0.00001 * t
#endif

#ifndef RAYMARCH_MAP_FNC
#define RAYMARCH_MAP_FNC(POS) raymarchMap(POS)
#endif

#ifndef RAYMARCH_MAP_TYPE
#define RAYMARCH_MAP_TYPE vec4
#endif

#ifndef RAYMARCH_MAP_DISTANCE
#define RAYMARCH_MAP_DISTANCE a
#endif

#ifndef RAYMARCH_MAP_MATERIAL
#define RAYMARCH_MAP_MATERIAL rgb
#endif

#ifndef RAYMARCH_MAP_MATERIAL_TYPE
#define RAYMARCH_MAP_MATERIAL_TYPE vec3
#endif

#ifndef FNC_RAYMARCHCAST
#define FNC_RAYMARCHCAST

RAYMARCH_MAP_TYPE raymarchCast( in vec3 ro, in vec3 rd ) {
    float tmin = RAYMARCH_MIN_DIST;
    float tmax = RAYMARCH_MAX_DIST;

// #if defined(RAYMARCH_FLOOR)
//     float tp1 = (0.0-ro.y)/rd.y; if( tp1>0.0 ) tmax = min( tmax, tp1 );
//     float tp2 = (1.6-ro.y)/rd.y; if( tp2>0.0 ) { if( ro.y>1.6 ) tmin = max( tmin, tp2 );
//                                                  else           tmax = min( tmax, tp2 ); }
// #endif

    float t = tmin;
    RAYMARCH_MAP_MATERIAL_TYPE m = RAYMARCH_MAP_MATERIAL_TYPE(-1.0);
    for ( int i = 0; i < RAYMARCH_SAMPLES; i++ ) {
        RAYMARCH_MAP_TYPE res = RAYMARCH_MAP_FNC( ro + rd * t );
        if ( res.RAYMARCH_MAP_DISTANCE < RAYMARCH_MIN_HIT_DIST || t > tmax ) 
            break;
        t += res.RAYMARCH_MAP_DISTANCE;
        m = res.RAYMARCH_MAP_MATERIAL;
    }

    #if defined(RAYMARCH_BACKGROUND) || defined(RAYMARCH_FLOOR)
    if ( t > tmax ) 
        m = RAYMARCH_MAP_MATERIAL_TYPE(-1.0);
    #endif

    return RAYMARCH_MAP_TYPE( m, t );
}

#endif

Dependencies:

Use:

<float> castRay( in <float3> pos, in <float3> nor )

Check it on Github



#ifndef RAYMARCH_SAMPLES
#define RAYMARCH_SAMPLES 64
#endif

#ifndef RAYMARCH_MAP_FNC
#define RAYMARCH_MAP_FNC(POS) raymarchMap(POS)
#endif

#ifndef RAYMARCH_MAP_TYPE
#define RAYMARCH_MAP_TYPE float4
#endif

#ifndef RAYMARCH_MAP_DISTANCE
#define RAYMARCH_MAP_DISTANCE a
#endif

#ifndef RAYMARCH_MAP_MATERIAL
#define RAYMARCH_MAP_MATERIAL rgb
#endif

#ifndef RAYMARCH_MAP_MATERIAL_TYPE
#define RAYMARCH_MAP_MATERIAL_TYPE float3
#endif

#ifndef FNC_RAYMARCHCAST
#define FNC_RAYMARCHCAST

RAYMARCH_MAP_TYPE raymarchCast( in float3 ro, in float3 rd ) {
    float tmin = 1.0;
    float tmax = 20.0;

// #if defined(RAYMARCH_FLOOR)
//     float tp1 = (0.0-ro.y)/rd.y; if( tp1>0.0 ) tmax = min( tmax, tp1 );
//     float tp2 = (1.6-ro.y)/rd.y; if( tp2>0.0 ) { if( ro.y>1.6 ) tmin = max( tmin, tp2 );
//                                                  else           tmax = min( tmax, tp2 ); }
// #endif

    float t = tmin;
    RAYMARCH_MAP_MATERIAL_TYPE m = float3( -1.0, -1.0, -1.0);
    for ( int i = 0; i < RAYMARCH_SAMPLES; i++ ) {
        float precis = 0.00001*t;
        RAYMARCH_MAP_TYPE res = RAYMARCH_MAP_FNC( ro + rd * t );
        if ( res.RAYMARCH_MAP_DISTANCE < precis || t > tmax ) 
            break;
        t += res.RAYMARCH_MAP_DISTANCE;
        m = res.RAYMARCH_MAP_MATERIAL;
    }

    #if defined(RAYMARCH_BACKGROUND) || defined(RAYMARCH_FLOOR)
    if ( t > tmax ) 
        m = float3(-1.0, -1.0, -1.0);
    #endif

    return RAYMARCH_MAP_TYPE( m, t );
}

#endif

Check it on Github

// #include "map.wgls"

fn raymarchCast(ro: vec3f, rd: vec3f ) -> f32 {
    var dist = -1.0;
    var t = -1.0;
    for (var i = 0; i < 120 && t < 100.0; i++) {
        let h = map( ro + rd * t );
        if (abs(h) < (0.001 * t)) { 
            dist = t; 
            break;
        }
        t += h;
    }
    return dist;
}

Dependencies:

Use:

<float> castRay( in <float3> pos, in <float3> nor )

Check it on Github



#ifndef RAYMARCH_SAMPLES
#define RAYMARCH_SAMPLES 64
#endif

#ifndef RAYMARCH_MAP_FNC
#define RAYMARCH_MAP_FNC(POS) raymarchMap(POS)
#endif

#ifndef RAYMARCH_MAP_TYPE
#define RAYMARCH_MAP_TYPE float4
#endif

#ifndef RAYMARCH_MAP_DISTANCE
#define RAYMARCH_MAP_DISTANCE w
#endif

#ifndef FNC_RAYMARCHCAST
#define FNC_RAYMARCHCAST

inline __host__ __device__ RAYMARCH_MAP_TYPE raymarchCast(const float3& ro, const float3& rd) {
    float tmin = 1.0;
    float tmax = 20.0;

// #if defined(RAYMARCH_FLOOR)
//     float tp1 = (0.0-ro.y)/rd.y; if( tp1>0.0 ) tmax = min( tmax, tp1 );
//     float tp2 = (1.6-ro.y)/rd.y; if( tp2>0.0 ) { if( ro.y>1.6 ) tmin = max( tmin, tp2 );
//                                                  else           tmax = min( tmax, tp2 ); }
// #endif

    float t = tmin;
    RAYMARCH_MAP_TYPE m = make_float4(-1.0f);
    for ( int i = 0; i < RAYMARCH_SAMPLES; i++ ) {
        float precis = 0.00001*t;
        RAYMARCH_MAP_TYPE res = RAYMARCH_MAP_FNC( ro + rd * t );
        if ( res.w < precis || t > tmax ) 
            break;
        t += res.w;
        m = res;
    }

    #if defined(RAYMARCH_BACKGROUND) || defined(RAYMARCH_FLOOR)
    if ( t > tmax ) 
        m = make_float4(-1.0);
    #endif

    m.RAYMARCH_MAP_DISTANCE = t;
    return m;
}

#endif

License

LYGIA is dual-licensed under the Prosperity License and the Patron License for sponsors and contributors.

Sponsors and contributors are automatically added to the Patron License and they can ignore the any non-commercial rule of the Prosperity Licensed software (please take a look to the exception).

It's also possible to get a permanent comercial license hook to a single and specific version of LYGIA.

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