Simple program to display 3D mesh? - linux

for a university project I have to compute a 3D mesh, then display it.
By mesh I mean a list of triangles, where each point has a specific elevation.
What is the easiest tool that exists both on windows and linux that would allow me to display such a mesh?
I just want to be able to visualize the mesh and rotate it, and I can code any specific mesh format needed to be used as an input.
What I mostly want is a tool that is easy to install for the final user of my program.

Almost every tool reads the .obj format, for example MeshMan, MeshLab and ArtOfIllusion. They all work under Windows and Linux. Geomview (.off-Files) is also great, but hard to install under Windows.

I'm using for this purpose osgviewer from OpenSceneGraph

I wouldn't know about the easiest tool, but have you tried Blender? It's cross platform.

There are some standard file formats for triangle meshes. Try outputing to .ply file and using one of the existing viewers for that.
I tend to use VTK file formats since I work in scientific visualization; that would be overkill for you.
In fact, I wrote a VTK/QT based app for viewing meshes that can handle .ply files https://github.com/HalCanary/vtkviewer.

Related

Easiest way to generate depth image/map from 3d model

I was wondering if anybody knew of an easy, robust way to generate depth images from 3d models (i.e. surface models, vertices with faces), with specifiable camera parameters.
I'd prefer "free" options if possible (e.g. pyOpengl or some open source Java library rather than say matlab).
I believe it is possible with the python blender api (noted here), but I'm hoping there's an easier way.
Note also that this question works only for that special case.
You can use DECA repository in Github. There, in ./demos, I used demo_reconstruct.py code to save the depth image.

How can I create a 3D model file from geometric shapes?

I am writing a program that will output 3D model files based on simple geometric shapes (e. g. rectangular prisms & cylinders) with known coordinates in 3-dimensional space. As an example, imagine creating a 3D model of stonehenge. this question suggests that OBJ files are the easiest to generate, but I'm struggling to find a good tutorial or easy-to-use library for doing so.
Can anyone either
(1) describe step-by-step how to create a simple file OR
(2) point me to a tutorial that describes how to do so
Notes:
* Using a GUI-based program to draw such files is not an option for me
* I have no prior experience with 3D modeling
* Other formats such as WRL or DAE would work for me as well
EDIT:
I do not need to use textures, just combinations of simple geometric shapes positioned in 3D space.
I strongly recommend to use some ASCII exchange format there are many out there I usually use these:
*.x DirectX object (it is a C++ source code)
this one is easiest to implement !!! But there are not many tools that can handle them. If you do not want to spend too much time coding then this is the right choice. Just copy the templates (at the start) from any *.x file to get started.
here some specs
*.iges common and importable on most CAD/CAM platform (Catia included)
this one is a bit complicated but for export purposes it is not that bad. It supports Volume operation like +,-,&,^ which are VERY HARD to implement properly but you do not have to use them :)
*.dxf AutoCAD exchange format
this one is even more complicated then IGES. I do not recommend to use it
*.ac AC3D
I first saw this one in flight gear.
here some specs
at first look it is quite easy but the sub-object implementation is really tricky. Unless you use it you should be fine.
This approach is easily verifiable in note pad or by loading to some 3D model viewer. Chose one that is most suitable for your needs and code save/load function to your Apps internal model class/struct. This way you will be compatible with other software and eliminate incompatibility problems which are native to creating 'almost known' binary formats like 3ds,...
In your case I would use IGES (Initial Graphics Exchange Specification)
For export you do not need to implement all just few basic shapes so it would not be too difficult. I code importers which are much much more complicated. Mine IGES loader class is about 30KB of C++ source code look here for more info
You did not provide any info about your 3D mesh model structure and capabilities
like what primitives you use, are your object simple or in skeleton hierarchy, are you using textures, and more ... so it is impossible to answer
Anyway export often looks like this:
create header and structure of target file format
if the format has any directory structure fill it and write it (IGES)
for sub-objects do not forget to add transformation matrices ...
write the chunks you need (points list, faces list, normals, ...)
With ASCII formats you can do this inside String variable so you can easily insert into or modify. Do all thing in memory and write the whole thing to file at the end which is fast and also add capability to work with memory instead of files. This is handy if you want to pack many files to single package file like *.pak or send/receive files through IPC or LAN ...
[Edit1] more about IGES
fileformat specs
I learned IGES from this pdf ... Have no clue where from I got it but this was first valid link I found in google today. I am sure there is some non registration link out there too. It is about 13.7 MB and original name IGES5-3_forDownload.pdf.
win32 viewer
this is free IGES viewer. I do not like the interface and handling but it works. It is necessary to have functional viewer for testing yours ...
examples
here are many tutorial files for many entities there are 3 sub-links (igs,peek,gif) where you can see example file in more ways for better understanding.
exporting to IGES
you did not provide any info about your 3D mesh internal structure so I can not help with export. There are many ways to export the same way so pick one that is closest to your App 3D mesh representation. For example you can use:
point cloud
rotation surfaces
rectangle (QUAD) surfaces
border lines representation (non solid)
trim surface and many more ...

3d cloud viewer?

I have a file which contains a bunch of points with their x,y, z locations.I am looking for a simple viewer where in I can load this point data and view it .Rotation is essential for me to check the depth of the cloud being generated .Can someone point out a light weight viewer with minimum installation overhead for this?
I have used MeshLab and it worked well for me. IIRC it uses your average Windows installer.
You could also try CyArk viewer (a Java applet), or Leica Cyclone -- I haven't used either one.
Of course if your data format is not a standard one, they may not be able to read it.
R+ is an open source statistical program that I have used for this exact purpose. It can be accomplished in only a few lines of code.
First add the rgl and plotrix libraries.
Enter the following code:
pcd <- read.table(file.choose(),sep="",skip=10)
names(pcd) <- c("x","y","z")
plot3d(pcd$x,pcd$y,pcd$z,col=color.scale(pcd$z,c(0,1,1),c(1,1,0),c(1,0,1)))
Where pcd is the type of file (if I remember correctly), the first ten lines are skipped as they are a header (skip=10) and sep"" represents the delimiter used in the file. This last line of code plots the points and sets the color based upon depth.
I vote for Paraview. I am shocked that no one mentioned it before I did.
No matter which OS you use, Windows, Mac OS or Linux you can use it without any (big) problems. (You know software always has bugs)
Meshlab is good too. In fact you can convert file format easily to make sure they can be used in different software, if you can learn Python.
I do believe someones has already done it. Eg. .off (Meshlab format) to .vtk(Paraview format), like this one.
Update1:
Most visualization softwares are user-friendly, so maybe the problem you have is mainly about how to convert the source data you have to the specified format which can be used in these viewers. It may be helpful if there is an example of data you have.
matlab is a quite good tool to visualize your pcl, expecially for further analysis.

3d models, LOD, pics, etc

I need to program a util for a 3d model. What i need to do is pass the 3d model to the util and have it extract multiple information. Things like poly count, size/scale (if applicable) and anything else i can grab. Then i need to take a screen shot of the model 8 times (45deg from 0 to 360). Maybe 16. Is there an app that i can use to extract data from the model and is there another app i can use to create the image? if so i can write a php script to do this all for me :) if not i'll post more question about specifics.
My OS is debian etch
the models will be any format. I may make it 3ds only or limit it to what the app(s) support. Or i may have another app to convert one format to the other and extract the data from that format.
I haven't tried this, but you could try 3ds2pov to convert your 3DS files into POV-Ray format, and then render with POV-Ray.
The 3ds2pov program is quite old, so I don't know how compatible it is with current 3DS files. The archive comes with source code so ought to build without too much difficulty on Debian.
POV-Ray itself runs easily on Linux.
nb: other 3DS to POV converters may exist. This one just happens to be the first one returned by Googling for "3ds to pov".
Your requirements are very loose and vague but most 3d engines should have the tools you need to create your custom utility. I would start by looking at Blender or the viewer tools from OGRE, OpensceneGraph and similar tools.
You can try this: Linux based A3dsViewer -> does 3ds to pov conversion.

Fast, Pixel Precision 2D Drawing API for Graphics App?

I woud like to create a cross-platform drawing program. The one requirement for writing my app is that I have pixel level precision over the canvas. For instance, I want to write my own line drawing algorithm rather than rely on someone elses. I do not want any form of anti-aliasing (again, pixel level control is required.) I would like the users interactions on the screen to be quick and responsive (pending my ability to write fast algorithms.)
Ideally, I would like to write this in Python, or perhaps Java as a second choice. The ability to easily make the final app cross-platform is a must. I will submit to different API's on different OS'es if necessary as long as I can write an abstraction layer around them. Any ideas?
addendum: I need the ability to draw on-screen. Drawing out to a file I've got figured out.
I just this week put together some slides and demo code for doing 2d graphics using OpenGL from python using the library pyglet. Here's a representative post: Pyglet week 2, better vertex throughput (or 3D stuff using the same basic ideas)
It is very fast (relatively speaking, for python) I have managed to get around 1,000 independently positioned and oriented objects moving around the screen, each with about 50 vertices.
It is very portable, all the code I have written in this environment works on windows and Linux and mac (and even obscure environments like Pypy) without me ever having to think about it.
Some of these posts are very old, with broken links between them. You should be able to find all the relevant posts using the 'graphics' tag.
The Pyglet library for Python might suit your needs. It lets you use OpenGL, a cross-platform graphics API. You can disable anti-aliasing and capture regions of the screen to a buffer or a file. In addition, you can use its event handling, resource loading, and image manipulation systems. You can probably also tie it into PIL (Python Image Library), and definitely Cairo, a popular cross-platform vector graphics library.
I mention Pyglet instead of pure PyOpenGL because Pyglet handles a lot of ugly OpenGL stuff transparently with no effort on your part.
A friend and I are currently working on a drawing program using Pyglet. There are a few quirks - for example, OpenGL is always double buffered on OS X, so we have to draw everything twice, once for the current frame and again for the other frame, since they are flipped whenever the display refreshes. You can look at our current progress in this subversion repository. (Splatterboard.py in trunk is the file you'll want to run.) If you're not up on using svn, I would be happy to email you a .zip of the latest source. Feel free to steal code if you look into it.
If language choice is open, a Flash file created with Haxe might have a place. Haxe is free, and a full, dynamic programming language. Then there's the related Neko, a virtual machine (like Java's, Ruby's, Parrot...) to run on Mac, Windows and Linux. Being in some ways a new improved form of Flash, naturally it can draw stuff. http://haxe.org/
QT's Canvas an QPainter are very good for this job if you'd like to use C++. and it is cross platform.
There is a python binding for QT but I've never used it.
As for Java, using SWT, pixel level manipulation of a canvas is somewhat difficult and slow so I would not recommend it. On the other hand Swing's Canvas is pretty good and responsive. I've never used the AWT option but you probably don't want to go there.
I would recommend wxPython
It's beautifully cross platform and you can get per pixel control and if you change your mind about that you can use it with libraries such as pyglet or agg.
You can find some useful examples for just what you are trying to do in the docs and demos download.

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