How can I convert a mesh file (.meshdat or .msh) into STL file format?
I have a 3D mesh file. I need to convert it into STL for a CFD problem.
Check out meshio (a project of mine). It knows a load of mesh formats, STL and msh amongst them.
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I tried to convert obj of world coords system into obj of local coords system using geopy and pyproj library.
Tried to convert epsg:5187 model into epsg:4326 but it seems a bit inaccurate.
(there are two models. green surface model and tunnel model. tunnel should be fit in green surface)
white tunnel model should be located where gray tunnel located, but it won't.
I guess it's because while mesh point is converted (world to local coords system), mesh's shape is different from original shape makes that problem.
i also thought merging objs is the best solution though i have to merge lots of objs which is large files exceed 3gb. (this should also be used in blender, but blender seems can't use it with too big file)
is this because geopy.geodesic is inaccurate, or inevitable in the process of transforming the coordinate system?
is there a way for converting models to be as it is not merging the models?
I working on a thermal tool using OptiX.
I started with the "meshviewer" example which uses syoyo's tinygltf loader.
Basically I want to import a file, get the number of primitives and then add up the intersections.
Now I imported a file containing two cubes, which should consist of 12 triangles each, so 24 in total. When I start my program the loader only recognizes 12 triangles, but it renders 2 seperate cubes. The primitive IDs seem to be identical for both cubes.
Is there a workaround when I export from blender? If I understood the documentation directly the separate cubes are treated as two "identical" instances of the same mesh and thus share the primitive IDs.
I am using the v2.81 of Blender with the gltf exporter.
Do I understand the problem correctly? And is there an easy workaround? If not it seems I will have to modify the tinygltf loader.
Thank you for help in advance!
It's possible the two cubes share the same mesh. In the screenshot below, there are two Blender "objects", Left-Cube and Right-Cube. Both objects use the same Blender mesh, called Shared-Cube-Mesh.
The glTF exporter recognizes this pattern and mirrors it in the glTF file. There will be two glTF nodes, corresponding to the two Blender objects that use the mesh. But there will only be a single glTF mesh, with a single cube.
You can click the "number of users" button, shown below with a white arrow pointing to it, to make the second object use its own unique mesh. But be warned, this doubles the amount of mesh data being exported to glTF in this simple example. A complete copy of the mesh would be made in both Blender and the glTF binary payload.
I have been trying to convert a digital binary file (.exe) into waveform to listen the resulted audio. I have been looking for any possible software/open source code to help me in achieving this, but no use.
My ultimate goal is to represent the .exe file as a spectogram to analyse the behaviour of the frequencies in the executable file. My understanding that I have to identify the range of frequencies first, which could be done by plotting the waveform first.
Any reference would be appreciated.
Edit:
I have a collection of binary files and I need to classify them according to their sound statistical features (frequency behaviour). My plan was to get the waveform of the actual binary file (by dividing the file into 1 signed byte each) and then convert the waveform into spectrogram picture and apply deep learning analysis for voice recognition
So, the depth of each sample will be 8-bits, and the sampling rate will be either 8Khz or 16 Khz. But I am confused of how to determine the frequencies related from the executable file
I'm relatively new to OGRE graphics engine, so my question may seem too obvious, but searching for relevant information was not successful.
Given:
I have an OGRE application with a scene created of some meshes, lights, cameras and textures. It is rather simple, I think. That all is represented by a tree of scene nodes(internal object).
The goal:
To save the full tree of scene nodes or, preferably, an indicated branch of nodes of the tree to a ".mesh" file. To be able load it later as any other mesh. The ".mesh.xml" format is also fine. How it could be done?
If not:
If the desired thing is not possible, what is normal way to create those ".mesh" files? And where I could find some guides for it?
I think you're a bit confused: OGRE mesh file is a file that stores only geometric data of a given 3D model like positions, normals, texture coordinates, tangents, binormals, bone index, bone weights and so on. It also can store a subdivision of a single mesh in submeshes (generally based on the material), and each of them can have a reference to the proper material. In essence a mesh file only contains data on the models you would like to load on your game, nothing about the scene structure.
If you want to save (serialize) your scene, you have two choice:
Write your own scene serializer.
Using some library already provided by the OGRE community: for example DotScene format.
There are Ogre .mesh exporters for programs like Blender. A quick google for Ogre .mesh exporters should help you.
I was able to use Ned Batchelder's python code, which I converted to C++, to extract jpgs from pdf files. I'm wondering if the same technique can be used to extract tiff files and if so, does anyone know the appropriate offsets and markers to find them?
Thanks,
David
PDF files may contain different image data (not surprisingly).
Most common cases are:
Fax data (CCITT Group 3 and 4)
raw raster data with decoding parameters and optional palette all compressed with Deflate or LZW compression
JPEG data
Recently, I (as developer of a PDF library) start noticing more and more PDFs with JBIG2 image data. Also, JPEG2000 sometimes can be put into a PDF.
I should say, that you probably can extract JPEG/JBIG2/JPEG2000 data into corresponding *.jpeg / *.jp2 / *.jpx files without external libraries but be prepared for all kinds of weird PDFs emitted by broken generators. Also, PDFs quite often use object streams so you'll need to implement sophisticated parser for PDF.
Fax data (i.e. what you probably call TIFF) should be at least packed into a valid TIFF. You can borrow some code for that from open source libtiff for example.
And then comes raw raster data. I don't think that it makes sense to try to extract such data without help of a library. You could do that, of course, but it will take months of work.
So, if you are trying to extract only specific kind of image data from a set of PDFs all created with the same generator, then your task is probably feasible. In all other cases I would recommend to save time, money and hair and use a library for the task.
PDF files store Jpegs as actual JPEGS (DCT and JPX encoding) so in most cases you can rip the data out. With Tiffs, you are looking for CCITT data (but you will need to add a header to the data to make it a Tiff). I wrote 2 blog articles on images in PDF files at http://www.jpedal.org/PDFblog/2010/09/understanding-the-pdf-file-format-images/ and http://www.jpedal.org/PDFblog/2011/07/extract-raw-jpeg-images-from-a-pdf-file/ which might help.