Create a curved plane surface which dynamically changes its size

hofk · June 10, 2020, 6:50pm

Constructively, this can be designed to match the sketch Create a curved plane surface which dynamically changes its size (page 8, left column only) like this

Only one triangle is necessary in addition to the triangles of the three streets.
The angle can be used for simple calculation of the coordinates of the vertices in the area of the branch.

ILove_hofk · June 11, 2020, 8:08am

Hi @hofk,

Thanks for your suggestion and I will have a try.

In addition, I’d like to ask another question that you mentioned above, page 16.

Since only the components x and z of the normal are used, but the y component is not always 0, it resulted in different road widths.

I followed your code but it didn’t work. I still got the different road widths if observing them carefully.

    for ( var j = 0; j < lss; j ++ ) { // length
        for ( var i = 0; i < wss; i ++ ) { // width

            // calculate here the coordinates according to your wishes

            tangent = curve.getTangent( j / ls ); //  .. / length segments
            normal.crossVectors( tangent, binormal ); 
            binormal.crossVectors( normal, tangent ); // new binormal

            normal.y = 0;

            normal.normalize();

            var lxz = Math.sqrt(normal.x*normal.x + normal.z*normal.z);
            var nx = normal.x / lxz;
            var nz = normal.z / lxz;

            //x = points[ j ].x + d[ i ] * normal.x;
            x = points[ j ].x + d[ i ] * nx;
            y = points[ j ].y;
            //z = points[ j ].z + d[ i ] * normal.z;
            z = points[ j ].z + d[ i ] * nz;

            xyzSet();
            vIdx ++;
        }
    }

My result is: