From 3f17c9607d6f4e0930f1bdc615578ed8f53ff1b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rostislav=20L=C3=A1n?= <lanrosta@seznam.cz>
Date: Sun, 25 Dec 2022 17:49:54 +0100
Subject: [PATCH] Added method to convert processed image to lithophane.

---
 src/main.py | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/src/main.py b/src/main.py
index 209140d..a25a030 100644
--- a/src/main.py
+++ b/src/main.py
@@ -197,6 +197,89 @@ class apply_filters:
 
     def make_lithophane(self):
         pass
+        '''After processing image, make a lithophane from it.
+        '''
+
+        print("Making meshgrid", file=sys.stderr)
+        self.make_meshgrid()
+        print("Converting to stl format", file=sys.stderr)
+        self.make_mesh()
+        plt.show()
+        self.save_model()
+
+    def make_meshgrid(self):
+
+        # Modify image to make it more suitable depth
+        # values1 = (1 + (1 - self.img/255)/6) * 255/10 # this works
+        # values2 = (1 - (1 - self.img/255)/6) * 255/10 # TODO: i dont know how to make white surrounding be extruded
+        values1better = 28.05 - 0.01*self.img
+        #values2better = 22.95 - 0.01*self.img
+        # (np.around(values2[::300],3))
+
+        # Add zero padding to image to make sides of the plate
+        self.height = self.img.shape[0] + 2
+        self.width = self.img.shape[1] + 2
+        self.img = np.zeros([self.height, self.width])
+        self.img[1:-1:1, 1:-1:1] = values1better
+
+        # Create meshgrid for 3D model
+        verticesX = np.around(np.linspace(0, self.width / 10, self.width), 3)
+        verticesY = np.around(np.linspace(0, self.height / 10, self.height), 3)
+        self.meshgrid = np.meshgrid(verticesX, verticesY)
+
+    def make_mesh(self):
+        # Convert meshgrid and image matrix to array of 3D points
+        vertice_arr = np.vstack(list(map(np.ravel, self.meshgrid))).T
+        z = (self.img / 10).reshape(-1, 1)
+        vertice_arr = np.concatenate((vertice_arr, z), axis=1)
+
+        # Convert back to matrix of 3D points
+        vertice_arr = vertice_arr.reshape(self.height, self.width, 3)
+
+        count = 0
+        vertices = []
+        faces = []
+
+        # Function to add faces to the list
+        def add_faces(c):
+            faces.append([c, c + 1, c + 2])
+            faces.append([c + 1, c + 3, c + 2])
+            c += 4
+            return c
+
+        # Iterate over all vertices, create faces
+        for j in range(self.width - 1):
+            for i in range(self.height - 1):
+
+                vertices.append([vertice_arr[i][j]])
+                vertices.append([vertice_arr[i][j+1]])
+                vertices.append([vertice_arr[i+1][j]])
+                vertices.append([vertice_arr[i+1][j+1]])
+
+                count = add_faces(count)
+
+        # Add faces for the backside of the lithophane
+        # This makes it closed, so it can be printed
+        vertices.append([vertice_arr[0][0]])
+        vertices.append([vertice_arr[0][self.width - 1]])
+        vertices.append([vertice_arr[self.height - 1][0]])
+        vertices.append([vertice_arr[self.height - 1][self.width - 1]])
+
+        count = add_faces(count)
+
+        # Convert to numpy arrays
+        faces = np.array(faces)
+        vertices = np.array(vertices)
+
+        # Create the mesh
+        self.model = mesh.Mesh(np.zeros(len(faces), dtype=mesh.Mesh.dtype))
+        for i, face in enumerate(faces):
+            for j in range(3):
+                self.model.vectors[i][j] = vertices[face[j], :]
+
+    def save_model(self):
+        print("Saving stl model", file=sys.stderr)
+        self.model.save('res/test.stl')
 
 
 image = apply_filters()