The line drawing in opengl is based on the use of vertices, i. Opengl an example to draw a sphere with vao and vbo github. Can anyone explain to me how i can draw a sphere using opengl. It is possible to use a single triangle strip to render the whole sphere. Basically to create a sphere, stack numbers and slice numbers are given, and there are two variables phi for slices and theta for stacks responsible for how much to progress. Many of these are modifications of programs in the opengl red book. Opengl extension for microsoft windows nt and windows 95 appendix d.
Opengl tutorial for 3d graphics primitives solid sphere. More specifically, we map an image of the earths surface onto a sphere. Well, i bought the book beginning opengl game programming, 2nd edition from borders and used the first example project after i finally got it to compile and everything, and then took their drawing code out and put mine in and modified things like glulookat bit by bit and sure enough, i can now make a 800x600 or 1024x768 screen with a nice, round planet. The program that we created in the first chapter will serve as the basis for the code in this chapter, so simply copy the file chapter. Texture map in solid sphere using glutopengl this source code is written in c used to draw a solid sphere using opengl and you can map texture in it. You should look into the function void drawspheredouble r, int lats, int longs. As for the opengl programming guide i was put off by this book as a beginner because right. Opengl tutorial 12 drawing a circle using a triangle fan. Applying a vertex in opengl is calling the following function glvertex3fx. In this post i would like to give a small intro on how to develop games or other 3d accelerated applications using them together. In this tutorial, we start with a single texture map on a sphere.
I need to draw a sphere in my project, without using the opengl function, because my project is to implement the opengl graphics pipeline. Opengl an example to draw a sphere with vao and vbo. Its the first in a series of tutorials about texturing in glsl shaders in opengl 2. I have, in the past, used it as a sphere approximation because the tris are uniformly distributed across the surface note drawing a sphere as longitude and latitude slices bunches up the tris at the poles. Opengl an example to draw a sphere with vao and vbo sphere. Opengl is well known to not posses any method to rasterize nonstraight curves. Opengl tutorial for 3d graphics primitives solid sphere wireframe sphere. An efficient way to draw approximate circles in opengl introduction. Each quad is made up of 4 vertices, defined in counterclockwise ccw order, such as the normal vector is pointing out, indicating the front face. There is a surprising lack of documentation on how to do so and it is. Opengls object is made up of primitives such as triangle, quad, polygon, point and line.
That often works better than the uvsphere, which means simply tesselating a sphere by longitude and latitude. If you want to render a sphere in 3d, for example in opengl or directx, it is often a good idea to use a subdivided icosahedron. Every time your of application does any drawing, its secretly creating vertices and uploading those to the graphics card using whats called a vertex array that gets uploaded to the. Like our content and want to support us more directly. The objects are the sun and the earth, drawn as wire spheres. And the process is divided into creating bottom cap, body, and top cap as seen below. There is also a site that has the code to drawing a sphere at this site but it doesnt explain the math behind drawing the sphere. Draw geometry at or near the same depth, but avoid unaesthetic artifacts from. In order to draw the surface of a sphere in opengl, you must triangulate adjacent vertices to form polygons. Check the opengl red book for the code for an icosohedron spelling. Renders a sphere centered at the modeling coordinates origin of the specified radius. Spherical coordinates to cartesian coordinates conversion glmvec3 direction.
This was sort of off putting for myself and i quickly dropped the book. You can rate examples to help us improve the quality of examples. The definition of sphere is a 3d closed surface where every point on the sphere is same distance radius from a given point. To enable the texture for sphere, first you need to define gluquadric pointer variable and assign memory to it by calling glunewquadric function. See the web site linked below for more information virtualglobebookopenglobe. This is the easiest mode to set up, with just these two lines from the texgen sample program. A sphere is drawn using a grey material characteristic. I have been stuck at thinking on about i can muli sphere at different location and zoom in until hit near plant and disapper and the next on go on until user hit esc.
The sphere can be represented graphically, or in ascii art, depending on the language capabilities. Sign in sign up instantly share code, notes, and snippets. However, if the shared vertices have different normals or texture coordinates, then a single triangle strip cannot be used. Texture coordinate generation texture mapping in opengl. How to draw opengl to a window you created in a dialog box with the resource editor without manually using createwindow. Now i want to change the code further as it gives a sphere. How to draw opengl to a window you created in a dialog box with the resource editor. To draw a textured sphere use glusphere function instead of glutsolidsphere.
I have searched but most of the solutions to drawing a sphere are to use glusphere. Create a project for opengl and copy and paste this code and use your desire image file for texture mapping. But it is very dependent of the number of vertices, so if you want many spheres, you have to draw few vertices per sphere. An efficient way to draw approximate circles in opengl. Glsl programminggluttextured spheres wikibooks, open. The triangles in an icosphere are a lot more evenly distributed over. Opengl tutorial for 3d graphics primitives solid sphere wireframe. Draw a solid sphere using opengl adding lighting to a solid sphere draw 3d cube using opengl add solid border to div change border style to solid at div tag sphere by lines drawing a rotating sphere rotate sphere in a circle with light opengl in java.
Solved how to draw a filled circle in opengl codeproject. Texture coordinate generation is enabled on the s, t, r. Well, i bought the book beginning opengl game programming, 2nd edition from borders and used the first example project after i finally got it. But the problem is the cube is ok but when i want to transform it into a sphere, the whole thing disappears. Error 1 the type or namespace name gluquadric could not be found are you missing a using directive or an assembly. I have also other versions of how to draw the sphere in polygon instead of. The light position is reset after the modeling transformation is called. Starting with the basics of creating a window the book makes you have to utilize a header file that i make. In tutorial 2, you will learn how to actually draw a triangle. Using opengl, you can create elegant and beautiful 3d graphics with. I am trying to create a simple program, when you click it will draw a sphere at the mouses location. Many of the 3d tutorials for opengl are just on cubes. Here are some opengl example programs, presented in an order in which new topics are added in each successive example. The sphere drawing functions precondition is to have the following given.