Add depth pass for picking a location

cura/DepthPass.py

@@ -0,0 +1,60 @@
+# Copyright (c) 2018 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+from UM.Application import Application
+from UM.Math.Color import Color
+from UM.Resources import Resources
+
+from UM.View.RenderPass import RenderPass
+from UM.View.GL.OpenGL import OpenGL
+from UM.View.RenderBatch import RenderBatch
+
+from UM.Scene.Iterator.DepthFirstIterator import DepthFirstIterator
+
+
+##  A RenderPass subclass that renders a depthmap of selectable objects to a texture.
+#   It uses the active camera by default, but it can be overridden to use a different camera.
+#
+#   Note that in order to increase precision, the 24 bit depth value is encoded into all three of the R,G & B channels
+class DepthPass(RenderPass):
+    def __init__(self, width: int, height: int):
+        super().__init__("preview", width, height, 0)
+
+        self._renderer = Application.getInstance().getRenderer()
+
+        self._shader = None
+        self._scene = Application.getInstance().getController().getScene()
+
+
+    def render(self) -> None:
+        if not self._shader:
+            self._shader = OpenGL.getInstance().createShaderProgram(Resources.getPath(Resources.Shaders, "camera_distance.shader"))
+
+        self._gl.glClearColor(0.0, 0.0, 0.0, 0.0)
+        self._gl.glClear(self._gl.GL_COLOR_BUFFER_BIT | self._gl.GL_DEPTH_BUFFER_BIT)
+
+        # Create a new batch to be rendered
+        batch = RenderBatch(self._shader)
+
+        # Fill up the batch with objects that can be sliced. `
+        for node in DepthFirstIterator(self._scene.getRoot()):
+            if node.callDecoration("isSliceable") and node.getMeshData() and node.isVisible():
+                batch.addItem(node.getWorldTransformation(), node.getMeshData())
+
+        self.bind()
+        batch.render(self._scene.getActiveCamera())
+        self.release()
+
+    ##  Get the distance in mm from the camera to at a certain pixel coordinate.
+    def getDepthAtPosition(self, x, y):
+        output = self.getOutput()
+
+        window_size = self._renderer.getWindowSize()
+
+        px = (0.5 + x / 2.0) * window_size[0]
+        py = (0.5 + y / 2.0) * window_size[1]
+
+        if px < 0 or px > (output.width() - 1) or py < 0 or py > (output.height() - 1):
+            return None
+
+        distance = output.pixel(px, py) # distance in micron, from in r, g & b channels
+        return distance / 1000.

plugins/SupportEraser/SupportEraser.py

@@ -4,14 +4,16 @@ from UM.Math.Vector import Vector
 from UM.Tool import Tool
 from PyQt5.QtCore import Qt, QUrl
 from UM.Application import Application
-from UM.Event import Event
+from UM.Event import Event, MouseEvent
 from UM.Mesh.MeshBuilder import MeshBuilder
 from UM.Operations.AddSceneNodeOperation import AddSceneNodeOperation
 from UM.Settings.SettingInstance import SettingInstance
 from cura.Scene.CuraSceneNode import CuraSceneNode
 from cura.Scene.SliceableObjectDecorator import SliceableObjectDecorator
 from cura.Scene.BuildPlateDecorator import BuildPlateDecorator
+from UM.Scene.Iterator.BreadthFirstIterator import BreadthFirstIterator
 from cura.Settings.SettingOverrideDecorator import SettingOverrideDecorator
+from cura.DepthPass import DepthPass
 
 import os
 import os.path
@@ -25,15 +27,22 @@ class SupportEraser(Tool):
     def event(self, event):
         super().event(event)
 
-        if event.type == Event.ToolActivateEvent:
+        if event.type == Event.MousePressEvent and self._controller.getToolsEnabled():
+            active_camera = self._controller.getScene().getActiveCamera()
 
-            # Load the remover mesh:
-            self._createEraserMesh()
+            # Create depth pass for picking
+            render_width, render_height = active_camera.getWindowSize()
+            depth_pass = DepthPass(int(render_width), int(render_height))
+            depth_pass.render()
 
-            # After we load the mesh, deactivate the tool again:
-            self.getController().setActiveTool(None)
+            distance = depth_pass.getDepthAtPosition(event.x, event.y)
+            ray = active_camera.getRay(event.x, event.y)
+            picked_position = ray.getPointAlongRay(distance)
 
-    def _createEraserMesh(self):
+            # Add the anto_overhang_mesh cube:
+            self._createEraserMesh(picked_position)
+
+    def _createEraserMesh(self, position: Vector):
         node = CuraSceneNode()
 
         node.setName("Eraser")
@@ -41,9 +50,7 @@ class SupportEraser(Tool):
         mesh = MeshBuilder()
         mesh.addCube(10,10,10)
         node.setMeshData(mesh.build())
-        # Place the cube in the platform. Do it manually so it works if the "automatic drop models" is OFF
-        move_vector = Vector(0, 5, 0)
-        node.setPosition(move_vector)
+        node.setPosition(position)
 
         active_build_plate = Application.getInstance().getMultiBuildPlateModel().activeBuildPlate
 

resources/shaders/camera_distance.shader

@@ -0,0 +1,83 @@
+[shaders]
+vertex =
+    uniform highp mat4 u_modelMatrix;
+    uniform highp mat4 u_viewProjectionMatrix;
+
+    attribute highp vec4 a_vertex;
+
+    varying highp vec3 v_vertex;
+
+    void main()
+    {
+        vec4 world_space_vert = u_modelMatrix * a_vertex;
+        gl_Position = u_viewProjectionMatrix * world_space_vert;
+
+        v_vertex = world_space_vert.xyz;
+    }
+
+fragment =
+    uniform highp vec3 u_viewPosition;
+
+    varying highp vec3 v_vertex;
+
+    void main()
+    {
+        highp float distance_to_camera = distance(v_vertex, u_viewPosition) * 1000.; // distance in micron
+
+        vec3 encoded; // encode float into 3 8-bit channels; this gives a precision of a micron at a range of up to ~16 meter
+        encoded.b = floor(distance_to_camera / 65536.0);
+        encoded.g = floor((distance_to_camera - encoded.b * 65536.0) / 256.0);
+        encoded.r = floor(distance_to_camera - encoded.b * 65536.0 - encoded.g * 256.0);
+
+        gl_FragColor.rgb = encoded / 255.;
+        gl_FragColor.a = 1.0;
+    }
+
+vertex41core =
+    #version 410
+    uniform highp mat4 u_modelMatrix;
+    uniform highp mat4 u_viewProjectionMatrix;
+
+    in highp vec4 a_vertex;
+
+    out highp vec3 v_vertex;
+
+    void main()
+    {
+        vec4 world_space_vert = u_modelMatrix * a_vertex;
+        gl_Position = u_viewProjectionMatrix * world_space_vert;
+
+        v_vertex = world_space_vert.xyz;
+    }
+
+fragment41core =
+    #version 410
+    uniform highp vec3 u_viewPosition;
+
+    in highp vec3 v_vertex;
+
+    out vec4 frag_color;
+
+    void main()
+    {
+        highp float distance_to_camera = distance(v_vertex, u_viewPosition) * 1000.; // distance in micron
+
+        vec3 encoded; // encode float into 3 8-bit channels; this gives a precision of a micron at a range of up to ~16 meter
+        encoded.b = floor(distance_to_camera / 65536.0);
+        encoded.g = floor((distance_to_camera - encoded.b * 65536.0) / 256.0);
+        encoded.r = floor(distance_to_camera - encoded.b * 65536.0 - encoded.g * 256.0);
+
+        frag_color.rgb = encoded / 255.;
+        frag_color.a = 1.0;
+    }
+
+[defaults]
+
+[bindings]
+u_modelMatrix = model_matrix
+u_viewProjectionMatrix = view_projection_matrix
+u_normalMatrix = normal_matrix
+u_viewPosition = view_position
+
+[attributes]
+a_vertex = vertex