.asc viewer using Kivy - python

I want to develop a 3D file viewer in kivy and python that reads and displays .asc mesh files of the format:
x1,y1,z1
x2,y2,z2
........
xi,yi,zi
What I have thought so far is to use a method similar to beginShape() of Processing so as to begin drawing a 3D shape then use a for-loop to append each point respectively.
I have also found that kivy example which parses .obj files and then displays them. Do you have any ideas on how can I make a similar ascparser and try to display my files?
Any help is greatly appreciated


I have also found that kivy example which parses .obj files and then displays them. Do you have any ideas on how can I make a similar ascparser and try to display my files?
Your best strategy at the moment is probably to read the objparser and try to understand what it is doing. The important thing is building a list of points and normals, which are passed to opengl via a Mesh with a custom vertex_format and custom shaders. In principle it wouldn't be very hard to do the same thing for your own filetype just by comparison with the .obj code, though you will need some understanding of what's going on (you can read about opengl and read the kivy source, if you haven't already) to make significant changes.
This is really an advanced topic right now, Kivy has very few pre-built wrappers to 3d opengl rendering. The backend is fully capable (so the 3d rendering example isn't that complex, for instance), but you probably do need some understanding of what's going on to accomplish things like your own task.
There are also a few other examples of 3d rendering in Kivy, which you might find helpful. nskrypnik has several repositories doing just this (see kivy-trackball, kivy-3dpicking, kivy-rotation3d), and seems to have begun implementing a proper 3d api in the kivy3 repo, though this is not complete and I suggest it as something you can learn about by reading, not something that can necessarily do what you want right now. The other nice example I've seen is a 3d inspector POC by tito, though it's just a proof of concept and not a polished product.

Related

3D mesh representation

Currently I'm developing a library to manage some stream of data, but at some point I'd like to represent my findings on 3d. I would like to develop a 3D view of my project:
I have:
- All the 3D vertices of one single block
- All the properties related with the object
The question is: Can I do this on python? Which library should I use? Is there any other solution rather than

Depending on what kind of display you are looking for.
if you need to display it as scientific data, there is VTK which propose a great variety of ways to display
if you want to operate your 3d data, display and inspect it at the same time, you can go for pymadcad (a lot of other modules are available for mesh manipulation only, but without display)
if you want a highly flexible rendering pipeline, you can take a look at moderngl, which is very close to the hardware reality by makes everything extremely simple
if you want a high interaction and flexibility in displaying meshes, maybe a game engine, like Panda3D can be more convenient

How to conform text to a surface using a displacement map in Python?

I am working on a project where I need to programmatically add a text to an image such that the text conforms to the surface so that it looks much more real-life.
Here is an example of what I am talking about:
https://www.youtube.com/watch?v=huvysaySBrw
I am fairly new when it comes to programmatic image editing. I have gone through quite a bit of documentation of ImageMagick and similar libraries. But didn't find anything that might help me so far.

Map a texture onto a model in Python

To frame this question: I am a complete beginner in terms of 3d rendering, and I would like to get my feet wet.
My goal is to create a command-line script (ideally in Python) which takes some kind of 3d model file (e.g. a sphere), maps a texture onto it, and outputs the result as an image file. That is, I would like my program to essentially be able to "do" the following:
From my reading, this appears to be something known as "uv mapping", but almost everything I've found on the subject in on how to do this using Blender, and I would prefer avoiding this: in a 2d analogy, it seems to me that Blender is like Photoshop where I'm looking for something like ImageMagick. Beyond that, I haven't been able to find much.
The closest I have found is this other stackoverflow question:
uv mapping works bad on low resolution (warning: lot of images)
But I don't quite understand what's going on there, because it doesn't import a 3d model at all -- it is my [perhaps mistaken?] understanding that EXR is a 2d image format.
Any guidance on how to get started would be greatly appreciated!

Render 3D model orthographically in Python

I want to write a tool in Python that will help me create isometric tiles from 3D-models. You see, I'm not a very proficient artist and free 3D-models are plentisome, and creating something like a table or chair is much easer in 3D than in painting.
This script will load a 3D model in orthographic projection and take pictures from four directions so it can be used in a game. I've tried this in Blender, but the results are inconsistent, very difficult to control and take very long time to create simple sprites.
Rolling my own script will probably let me do neat things too, especially batch-genetration, maybe on texture changes, shading, etc. The game itself will probably be made in Python tpp, so maybe I could generate on the fly. (Edit: and automatically creat cut out see-through walls for when they face camera)
Now my question, what Python libraries can do something like this? I've checked both Pyglet and Panda3D, but I haven't even been able to load a model, let alone set it to orthographic projection.

I found this code:
www.pygame.org/wiki/OBJFileLoader
It let me load and display an .obj file of a cube from Blender with ease. It runs PyOpenGL so it should let me do everything OpenGL can. Never knew OpenGL was so low-level, didn't realize I'd have to write my own loaders and everything.
Anyway, I'm pretty sure I can modify this to project isometrically, rotate the object and grab shots and combine them into sprites. Thanks you guys!

Since you looked at Panda3D - if you can convert your model to the 'egg' format (which blender/maya may do), then you could be able to import it.
https://www.panda3d.org/manual/index.php/Loading_Models
https://www.panda3d.org/manual/index.php/Models_and_Actors
http://www.panda3d.org/manual/index.php/Converting_from_Blender
Note: sources of this was 'python 3d mesh loader' in a popular search engine - this looks viable to me. I now need to try installing it and some code...

Recommendations for a simple 2D graphics python library that can output to screen and pdf?

I'm looking for an easy-to-use graphics lib for python that can output to screen as well as pdf. So, I would use code to draw some stuff (simple prims like ovals, rectangles, lines and points) to screen and then when things look good, have it output to pdf.

If you use Tkinter, you can draw on a Canvas widget, then use its .postscript method to save the contents as a PostScript file, which you can convert to PDF using ps2pdf.
postscript(self, cnf={}, **kw)
Print the contents of the canvas to a postscript
file. Valid options: colormap, colormode, file, fontmap,
height, pageanchor, pageheight, pagewidth, pagex, pagey,
rotate, witdh, x, y.

Matplotlib should be able to do it. See event handling here: http://matplotlib.sourceforge.net/examples/event_handling/index.html

You can use the Python Imaging Library for drawing images which can easily be displayed in various UIs, e.g. by displaying a jpg. Then, use ReportLab. Here's an example which shows how to use ReportLab with an image.
I'm not sure what you mean by drawing to "screen", i.e. if you're working with a specific UI toolkit. But if it's acceptable to draw and display PDFs without using an intermediate image (jpg, etc), then you might consider the PyX library, which makes it quite simple to do graphics with PDFs.

You could look into matplotlib, which is mainly for plotting but you could probably do some basic drawing.
Then there is pygame. But I'm not so sure if it can generate a pdf, however you can do 2D graphics with it.
There is something called ReportLab that can generate pdf's. Here is a bunch of tutorials using it.

This is a tricky question, because there are so many libraries available - there is a trade-off between beauty/easiness.
What I've done and works great is to produce the Postscript directly, it is not difficult at all, and you can preview it using Ghostview; converting tyo PDF is trivial (ps2pdf). Learning how to tell Postscript to create lines and circles is extremely simple.
If you want more extensibility, then go to Matplotlib, but beware of the many times when it will "decide for you what looks best" even if you don't like it.
Good luck.

Creating PDFs is always a pain, it doesn't make sense if you do not aim to lose sanity.
With that said, you are aiming to do two completely different things: when you draw to screen you draw into a raster bitmap, while PDFs are mostly dynamic, like HTML. (unlike HTML they are more prone to be the same over different platforms, but that's beside the point)
If you really want to do that, the solution might be finding something that outputs PDFs, and then showing the generated PDF on screen at every step.
I guess that's the only way to have WYSIWYG results.

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