STL scene loader

Now using trimesh

Author: einarf

demosys/conf/default.py

@@ -76,6 +76,7 @@
 SCENE_LOADERS = (
     "demosys.loaders.scene.gltf.GLTF2",
     "demosys.loaders.scene.wavefront.ObjLoader",
+    "demosys.loaders.scene.stl_loader.STLLoader",
 )
 
 DATA_DIRS = ()

demosys/loaders/scene/stl_loader.py

@@ -0,0 +1,45 @@
+import gzip
+
+import moderngl
+import numpy
+import trimesh
+
+from demosys.loaders.scene.base import SceneLoader
+from demosys.opengl.vao import VAO
+from demosys.resources.meta import SceneDescription
+from demosys.scene import Material, MaterialTexture, Mesh, Node, Scene
+
+
+class STLLoader(SceneLoader):
+    file_extensions = [
+        ['.stl'],
+        ['.stl', '.gz'],
+    ]
+
+    def load(self):
+        path = self.find_scene(self.meta.path)
+        if not path:
+            raise ValueError("Scene '{}' not found".format(self.meta.path))
+
+        file_obj = str(path)
+        if file_obj.endswith('.gz'):
+            file_obj =  gzip.GzipFile(file_obj)
+
+        stl_mesh = trimesh.load(file_obj, file_type='stl')
+        scene = Scene(self.meta.resolved_path)
+        scene_mesh = Mesh("mesh")
+        scene_mesh.material = Material("default")
+
+        vao = VAO("mesh", mode=moderngl.TRIANGLES)
+        vao.buffer(numpy.array(stl_mesh.vertices, dtype='f4'), '3f', ['in_position'])
+        vao.buffer(numpy.array(stl_mesh.vertex_normals, dtype='f4'), '3f', ['in_normal'])
+        vao.index_buffer(numpy.array(stl_mesh.faces, dtype='u4'))
+        scene_mesh.vao = vao
+        scene_mesh.add_attribute('POSITION', 'in_position', 3)
+        scene_mesh.add_attribute('NORMAL', 'in_normal', 3)
+
+        scene.meshes.append(scene_mesh)
+        scene.root_nodes.append(Node(mesh=scene_mesh))
+        scene.prepare()
+
+        return scene

setup.py

@@ -33,6 +33,7 @@
         'pyrocket==0.2.8',
         'PyWavefront==1.0.2 ',
         'PyQt5==5.11.3',
+        'trimesh==2.36.3',
     ],
     extras_require={
         "glfw": ['glfw==1.7.0'],