LYGIA Shader Library

softShadow (lygia/v1.1.6/lighting/raymarch/softShadow)

calculate soft shadows http://iquilezles.org/www/articles/rmshadows/rmshadows.htm

Dependencies:

Use:

<float> raymarchSoftshadow( in <vec3> ro, in <vec3> rd, in <float> tmin, in <float> tmax)

Check it on Github



#ifndef RAYMARCHSOFTSHADOW_ITERATIONS
#define RAYMARCHSOFTSHADOW_ITERATIONS 16
#endif

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

#ifndef RAYMARCH_MAP_DISTANCE
#define RAYMARCH_MAP_DISTANCE a
#endif

#ifndef FNC_RAYMARCHSOFTSHADOW
#define FNC_RAYMARCHSOFTSHADOW

float raymarchSoftShadow( vec3 ro, vec3 rd, in float tmin, in float tmax, float k ) {
    float res = 1.0;
    float t = tmin;
    float ph = 1e20;
    for (int i = 0; i < RAYMARCHSOFTSHADOW_ITERATIONS; i++) {
        float h = RAYMARCH_MAP_FNC(ro + rd*t).RAYMARCH_MAP_DISTANCE;

        if (t > tmax)
            break;

        else if (h < 0.001) {
            res = 0.0;
            break;
        }

        float y = h*h/(2.0*ph);
        float d = sqrt(h*h-y*y);
        res = min( res, k*d/max(0.0,t-y) );
        ph = h;
        t += h;
    }
    return res;
}

float raymarchSoftShadow( vec3 ro, vec3 rd, in float tmin, in float tmax) { return raymarchSoftShadow(ro, rd, tmin, tmax, 12.0); }
float raymarchSoftShadow( vec3 ro, vec3 rd) { return raymarchSoftShadow(ro, rd, 0.05, 5.0); }

#endif

Dependencies:

Use:

<float> raymarchSoftshadow( in <float3> ro, in <float3> rd, in <float> tmin, in <float> tmax)

Check it on Github



#ifndef RAYMARCHSOFTSHADOW_ITERATIONS
#define RAYMARCHSOFTSHADOW_ITERATIONS 16
#endif

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

#ifndef RAYMARCH_MAP_DISTANCE
#define RAYMARCH_MAP_DISTANCE a
#endif

#ifndef FNC_RAYMARCHSOFTSHADOW
#define FNC_RAYMARCHSOFTSHADOW

float raymarchSoftShadow( float3 ro, float3 rd, in float tmin, in float tmax, float k ) {
    float res = 1.0;
    float t = tmin;
    float ph = 1e20;
    for (int i = 0; i < RAYMARCHSOFTSHADOW_ITERATIONS; i++) {
        float h = RAYMARCH_MAP_FNC(ro + rd*t).RAYMARCH_MAP_DISTANCE;

        if (t > tmax)
            break;

        else if (h < 0.001) {
            res = 0.0;
            break;
        }

        float y = h*h/(2.0*ph);
        float d = sqrt(h*h-y*y);
        res = min( res, k*d/max(0.0,t-y) );
        ph = h;
        t += h;
    }
    return res;
}

float raymarchSoftShadow( float3 ro, float3 rd, in float tmin, in float tmax) { return raymarchSoftShadow(ro, rd, tmin, tmax, 12.0); }
float raymarchSoftShadow( float3 ro, float3 rd) { return raymarchSoftShadow(ro, rd, 0.05, 5.0); }

#endif

Dependencies:

Use:

<float> raymarchSoftshadow( in <float3> ro, in <float3> rd, in <float> tmin, in <float> tmax)

Check it on Github



#ifndef RAYMARCHSOFTSHADOW_ITERATIONS
#define RAYMARCHSOFTSHADOW_ITERATIONS 16
#endif

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

#ifndef RAYMARCH_MAP_DISTANCE
#define RAYMARCH_MAP_DISTANCE w
#endif

#ifndef FNC_RAYMARCHSOFTSHADOW
#define FNC_RAYMARCHSOFTSHADOW

inline __host__ __device__ float raymarchSoftShadow(const float3& ro, const float3& rd, float tmin, float tmax, float k ) {
    float res = 1.0f;
    float t = tmin;
    float ph = 1e20;
    for (int i = 0; i < RAYMARCHSOFTSHADOW_ITERATIONS; i++) {
        float h = RAYMARCH_MAP_FNC(ro + rd*t).RAYMARCH_MAP_DISTANCE;

        if (t > tmax)
            break;

        else if (h < 0.001) {
            res = 0.0;
            break;
        }

        float y = h * h / (2.0f * ph);
        float d = sqrt( h * h - y * y);
        res = min( res, k * d / max(0.0f, t - y) );
        ph = h;
        t += h;
    }
    return res;
}

inline __host__ __device__ float raymarchSoftShadow(const float3& ro, const float3& rd, float tmin, float tmax) { return raymarchSoftShadow(ro, rd, tmin, tmax, 12.0f); }
inline __host__ __device__ float raymarchSoftShadow(const float3& ro, const float3& rd) { return raymarchSoftShadow(ro, rd, 0.05f, 5.0f); }

#endif

Examples

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