osh-js/source/core/ui/view/map/shaders/ImageDrapingFS.js

OSH javascript Toolkit

export default `
in vec3 v_positionEC;
in vec3 v_normalEC;
in vec2 v_st;

vec4 windowToEye(vec4 fragCoord)
{
    vec2 uv = fragCoord.xy / czm_viewport.zw;
    float z_window = czm_unpackDepth(texture(czm_globeDepthTexture, uv));

    //
    if (z_window == 0.0)
        discard;

    vec4 eyeCoordinate = czm_windowToEyeCoordinates(fragCoord.xy, z_window);
    //
    return eyeCoordinate / eyeCoordinate.w;
}

// Camera model and frames are based on OpenCV conventions:
// http://docs.opencv.org/2.4/modules/calib3d/doc/camera_calibration_and_3d_reconstruction.html
// we pass in a normalized intrinsic matrix as uniform so we can compute the normalized texture coordinates directly

void main()
{
    vec3 positionToEyeEC = -v_positionEC;
    
    // get fragment 3D pos in eye coordinates using depth buffer value at fragment location
    vec4 v_posEC = windowToEye(gl_FragCoord);

    // translate to video cam frame
    vec4 camPosEC = czm_modelViewRelativeToEye * czm_translateRelativeToEye(camPosHigh_1, camPosLow_2);
    vec4 v_posCam = v_posEC - camPosEC;

    // rotate to video cam frame
    vec3 lookRay = camAtt_3 * czm_inverseViewRotation3D * v_posCam.xyz;

    // discard if behind camera
    if (lookRay.z < 0.1)
        discard;

    // undistort
    float xn = lookRay.x / lookRay.z;
    float yn = lookRay.y / lookRay.z;
    float k1 = camDistR_5[0];
    float k2 = camDistR_5[1];
    float k3 = camDistR_5[2];
    float p1 = camDistT_6[0];
    float p2 = camDistT_6[1];

    float r2 = xn * xn+ yn * yn;
    float r4 = r2 * r2;
    float r6 = r4 * r2;
    float xd = xn * (1. + k1 * r2 + k2 * r4 + k3 * r6) + 2. * p1 * xn * yn + p2 * (r2 + 2. * xn * xn);
    float yd = yn * (1. + k1 * r2 + k2 * r4 + k3 * r6) + 2. * p2 * xn * yn + p1 * (r2 + 2. * yn * yn);

    // project with pinhole model
    vec3 st = camProj_4 * vec3(xd, yd, 1.);
    st.y = 1.0 - st.y;

    if (st.x < 0.0 || st.x > 1.0 || st.y < 0.0 || st.y > 1.0)
        discard;

    // get color from material
    czm_materialInput materialInput;
    materialInput.positionToEyeEC = positionToEyeEC;
    materialInput.st = vec2(st.x, st.y);
    czm_material material = czm_getMaterial(materialInput);
    out_FragColor = vec4(material.diffuse + material.emission, material.alpha);

    //float depth = pow(v_posEC.z * 0.5 + 0.5, 8.0);
    //gl_FragColor = vec4(depth, depth, depth, 1.0);
}`;