![]() ![]() Mathematically, this is equivalent to the "idiomatic" (for lack of a better word) sentence dist = p1 - p1 # the "norm" of the vector difference, subtraction.Ĭurrently, I get my distance like this: p1 = Programmatically, euclidean distance is given by dist = ((p2 - p1)**2 + (p2 - p1)**2)**0.5 I have a function that I use like this: dist = geodistance(p1, p2) which is analog to euclidean distance in linear algebra (vector subtraction/difference), but occurs in geodesical (spherical) space instead of rectangular euclidean space. Initialize and return your parent mesh object: mesh = normalBuffer] vertexCount:plane.I am currently using Python/Numpy to deal with geographical/GPS data (loving it!), and I am facing the recurring task to calculate distances between geographical points defined by a coordinate pair pn =. However I was *not* able to get the normal generation working, I ended up having to generate my normals manually as before so I am not sure how useful it is really, probably not useful at all tbh, the only thing I like about it is it makes the renderer code a bit cleaner because all of my meshes end up being MTKMesh.ĥ. Initialize and return your parent mesh object: mesh = normalBuffer] vertexCount:plane.vertexCount descriptor:mdlVertexDescriptor used initWithVertex data for a plane mesh that I generated programatically. Initialize your submesh with the index buffer: initWithIndexBuffer:indexBuffer indexCount:plane.indexCount indexType:MDLIndexBitDepthUInt16 geometryType:MDLGeometryTypeTriangleStrips material:nil] ĥ. MTKMeshBuffer * indexBuffer = (MTKMeshBuffer *) Ĥ. MTKMeshBuffer * normalBuffer = (MTKMeshBuffer *) MTKMeshBuffer * vertexBuffer = (MTKMeshBuffer *) MTKMeshBufferAllocator * allocator = initWithDevice:device] Create your position vertex, normal, and index buffers like so: Use this object to initialize the MDLVertexDescriptor object via MTKModelIOVertexDescriptorFromMetalģ. Create the MTLVertexDescriptor object that describes how your programatically generated verticies and normals are laid out in memoryĢ. If you still want to do it try to follow these steps and let me know if you have any problems.ġ. I think Model I/O is meant to read from a obj file directly then that way it has full control over how the buffers are created on the device. However I was *not* able to get the normal generation working, I ended up having to generate my normals manually as before so I am not sure how useful it is really, probably not useful at all tbh, the only thing I like about it is it makes the renderer code a bit cleaner because all of my meshes end up being MTKMesh. I used initWithVertex data for a plane mesh that I generated programatically. To put it in yet a different way, I'd like to see some more examples/sample code from Apple (or anyone else of course) on creating and rendering (in scenekit or metal) an MDLMesh not loaded from an asset like the fighter jet but from vertex data for a simple cube or 4-vertex plane even. Long story short, how can I go from SCNVector vertexpos and int indices (currently stored as described here: z) to an MDLMesh directly. Specifcally it seems nobody (as a matter of speaking, based on google search) uses initWithVertexBuffer of MDLMesh. ![]() The few code samples I could find cover at best how to create an MDLMesh from an asset, I would very much appreciate an (obj c) sample of how to use MDLMesh with programmatically generated vertex data instead. I then use geometrySourceWithVertices to create the geometry source, and then use geometrySourceWithData to create the SCNGeometryElement from the incides and another SCNGeometrySource for the color data (on a side note it appears there could or should be a geometrySourceWithColors too). Aside from the memory leaks in subdivision (another topic.) that works, but it's obviously not efficient and affects performance negavtively.ĭuring rebuilding of the geometry (based on the half edge data structure's data) I end up with basic arrays for vertex positions and indices and colors. I can load the SCNGeometry into an MDLMesh, create another one based on that using initMeshBySubdividingMesh and then generate normals and then turn it into SCNGeometry again. I want to utilize the normal generation and subdivision and file export options etc from ModelIO. I currently use geometryWithSources to generate a SCNGeometry object and assign that to an SCNNode. Specifically I have a half-edge datastructure that is updated frequently (though not every frame). The bold part is what I aim to do, create meshes from my own vertex data. You can also create meshes from your own vertex data or create parametric meshes" As written in the docs for MDLMesh: "Typically, you obtain meshes by traversing the object hierarchy of a MDLAsset object, but ![]()
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