# Plotting – Determine the tangents of the function in each network

I have a 2D graph that contains a curve table within a circular area.

``````Rotationsparametrisch[parfunc_, fixedpoint_, angle_] : =
rotation matrix[angle](parfunc - fixpoint) + fixpoint;
viewAngle = Pi / 3;
ctrVolume = {(Exp[(Pi - viewAngle)*0.5] + 1) / 2, 0};
radiusVolume = (Exp[(Pi - viewAngle)*0.5] - 1) / 2;
radiusRing = (Exp[(Pi - viewAngle)*0.5] + 1) / 2;
FPS = 120 * 3;
fPlanet = 3;
fOrbit = 10;
planetRotation =
0}, -2 * Pi * i * fPlanet / FPS]mirrorPlanetRotation =
0}, Pi - 2 * Pi * i * fPlanet / FPS]orbit rotation =
Rotationsparametrisch[planetRotation, ctrVolume, -2*Pi*i*fOrbit/FPS]
mirrorOrbitRotation =
Rotationsparametrisch[planetRotation, ctrVolume, Pi - 2*Pi*i*fOrbit/FPS]
TheCurves = Evaluate @ Table[orbitRotation, {i, 1, FPS}];
TheMirrorCurves = Evaluate @ Table[mirrorOrbitRotation, {i, 1, FPS}];
pp = Parametric Plot[{TheCurves, TheMirrorCurves}, {t, 0,
Pi - viewAngle},
RegionFunction -> (Norm[{#, #2} - ctrVolume] <= radiusVolume &),
PlotRange ->    Everything]
``````

This is the output:

What I would like to do first is to divide the region into individual small regions (meshes), which I will decide on the size of the meshes. For example as below:

Then I need to extract the tangent values ​​of each curve within the grid so that I can calculate the angle of the vertical vectors as follows:

If it will help, I need this to calculate the minimal voxel in a holographic volume. If I find the angle of the vertical vectors, I know the total viewing angle of the voxel (net). If the total angle is 360 degrees, then I have reached my goal. Many Thanks.