Sign in to follow this  
HHKUPM

OpenGL OpenGL with text files

Recommended Posts

Dear All, I have a question and a problem need to be solved asap so i need your appreciated help. I have a data of (x,y,z) were saved in a text file and i need to show these data in 3D (render them).I used lesson 25 from NeHe's website here and i improved it to fit with my text file and it drew the data but the problem is that they were not in the shape of complete 3D. I got like slices of (x,y) and separated by (z). I need to connect these points so it would look like one complete shape and i have tried all functions of (GL_lines, GL_polygons,GL_points, etc) but none of them did the job. Please if you have any suggestions for me to get good results i would highly appreciate them. If you need more details about my data or the source code just ask and i will support you with all till we get to the final result. I am not that good in programming and i really need your help. Thank you.

Share this post


Link to post
Share on other sites
I sounds like you want to render a volume that encloses all the points, correct? In this case, I am afraid that there is no simple way to do this. You need to construct the convex hull of your set of points, and render that as a polygonal mesh. I don't have a simple answer for you, but here is a decent overview of the possible algorithms to perform this.

Share this post


Link to post
Share on other sites
Thank you for your fast reply swiftcoder and i really appreciate it.Yes as you said i need to render my points and get them to look in decent look. Right now i have them in 3D but the problem is x and y look in slices and z just separate between them but not like sphere or complete 3D. I tried to use mesh function btu did not work with me. Can you give me an examples of how to use mesh or polygonal mesh function? Do you have any source code examples for rendering data from text files please? Sorry for asking too much but im not really good in programming...if you have anything want to send it please send it to my email hassanhadi2@yahoo.com and i will reallt appreciate it for you my friend. Thank you.

Share this post


Link to post
Share on other sites
my problem is how to connect the 3 vertices (x,y,and z) together to look like mesh shape. My data for a gray-scale image and i just need to show my data in simple mesh shape. Does anyone know how to do mesh with these data? Thank you.

my code to show the data is like this:

function DrawGLScene():bool;
var
tx, ty, tz: GLfloat;
q: Vertex;
i: integer;
begin
glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(cx,cy,cz);
glRotatef(xrot,1.0,0.0,0.0);
glRotatef(yrot,0.0,1.0,0.0);
glRotatef(zrot,0.0,0.0,1.0);
xrot := xrot + xspeed;
yrot := yrot + yspeed;
zrot := zrot + zspeed;
//glBegin(GL_points);
glLineWidth(20);
glBegin(GL_line_strip);

for i := 0 to morph1.verts - 1 do
begin
if morph then q := Calculate(i)
else
begin
q.x := 0.0;
q.y := 0.0;
q.z := 0.0;
end;
helper.points[i].x := helper.points[i].x - q.x;
helper.points[i].y := helper.points[i].y - q.y;
helper.points[i].z := helper.points[i].z - q.z;
tx := helper.points[i].x;
ty := helper.points[i].y;
tz := helper.points[i].z;

glVertex3f(tx,ty,tz); glColor3f(0.0,0.5,1.0);
tx := tx - q.x;
ty := ty - q.y;
tz := tz - q.z;

glVertex3f(tx,ty,tz); glColor3f(0.0,0.0,1.0);
tx := tx - q.x;
ty := ty - q.y;
tz := tz - q.z;

glVertex3f(tx,ty,tz);
end;
glEnd;

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • Partner Spotlight

  • Forum Statistics

    • Total Topics
      627636
    • Total Posts
      2978331
  • Similar Content

    • By xhcao
      Before using void glBindImageTexture(    GLuint unit, GLuint texture, GLint level, GLboolean layered, GLint layer, GLenum access, GLenum format), does need to make sure that texture is completeness. 
    • By cebugdev
      hi guys, 
      are there any books, link online or any other resources that discusses on how to build special effects such as magic, lightning, etc. in OpenGL? i mean, yeah most of them are using particles but im looking for resources specifically on how to manipulate the particles to look like an effect that can be use for games,. i did fire particle before, and I want to learn how to do the other 'magic' as well.
      Like are there one book or link(cant find in google) that atleast featured how to make different particle effects in OpenGL (or DirectX)? If there is no one stop shop for it, maybe ill just look for some tips on how to make a particle engine that is flexible enough to enable me to design different effects/magic 
      let me know if you guys have recommendations.
      Thank you in advance!
    • By dud3
      How do we rotate the camera around x axis 360 degrees, without having the strange effect as in my video below? 
      Mine behaves exactly the same way spherical coordinates would, I'm using euler angles.
      Tried googling, but couldn't find a proper answer, guessing I don't know what exactly to google for, googled 'rotate 360 around x axis', got no proper answers.
       
      References:
      Code: https://pastebin.com/Hcshj3FQ
      The video shows the difference between blender and my rotation:
       
    • By Defend
      I've had a Google around for this but haven't yet found some solid advice. There is a lot of "it depends", but I'm not sure on what.
      My question is what's a good rule of thumb to follow when it comes to creating/using VBOs & VAOs? As in, when should I use multiple or when should I not? My understanding so far is that if I need a new VBO, then I need a new VAO. So when it comes to rendering multiple objects I can either:
      * make lots of VAO/VBO pairs and flip through them to render different objects, or
      * make one big VBO and jump around its memory to render different objects. 
      I also understand that if I need to render objects with different vertex attributes, then a new VAO is necessary in this case.
      If that "it depends" really is quite variable, what's best for a beginner with OpenGL, assuming that better approaches can be learnt later with better understanding?
       
    • By test opty
      Hello all,
       
      On my Windows 7 x64 machine I wrote the code below on VS 2017 and ran it.
      #include <glad/glad.h>  #include <GLFW/glfw3.h> #include <std_lib_facilities_4.h> using namespace std; void framebuffer_size_callback(GLFWwindow* window , int width, int height) {     glViewport(0, 0, width, height); } //****************************** void processInput(GLFWwindow* window) {     if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)         glfwSetWindowShouldClose(window, true); } //********************************* int main() {     glfwInit();     glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);     glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);     glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);     //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);     GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", nullptr, nullptr);     if (window == nullptr)     {         cout << "Failed to create GLFW window" << endl;         glfwTerminate();         return -1;     }     glfwMakeContextCurrent(window);     if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))     {         cout << "Failed to initialize GLAD" << endl;         return -1;     }     glViewport(0, 0, 600, 480);     glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);     glClearColor(0.2f, 0.3f, 0.3f, 1.0f);     glClear(GL_COLOR_BUFFER_BIT);     while (!glfwWindowShouldClose(window))     {         processInput(window);         glfwSwapBuffers(window);         glfwPollEvents();     }     glfwTerminate();     return 0; }  
      The result should be a fixed dark green-blueish color as the end of here. But the color of my window turns from black to green-blueish repeatedly in high speed! I thought it might be a problem with my Graphics card driver but I've updated it and it's: NVIDIA GeForce GTX 750 Ti.
      What is the problem and how to solve it please?
  • Popular Now