How to calculate Tangent and Binormal?

The relevant input data to your problem are the texture coordinates. Tangent and Binormal are vectors locally parallel to the object’s surface. And in the case of normal mapping they’re describing the local orientation of the normal texture. So you have to calculate the direction (in the model’s space) in which the texturing vectors point. … Read more

How to draw text using only OpenGL methods?

Theory Why it is hard Popular font formats like TrueType and OpenType are vector outline formats: they use Bezier curves to define the boundary of the letter. Image source. Transforming those formats into arrays of pixels (rasterization) is too specific and out of OpenGL’s scope, specially because OpenGl does not have non-straight primitives (e.g. see … Read more

How to get the GL library/headers?

Windows On Windows you need to include the gl.h header for OpenGL 1.1 support and link against OpenGL32.lib. Both are a part of the Windows SDK. In addition, you might want the following headers which you can get from http://www.opengl.org/registry . <GL/glext.h> – OpenGL 1.2 and above compatibility profile and extension interfaces.. <GL/glcorearb.h> – OpenGL … Read more

Python – No handlers could be found for logger “OpenGL.error”

Looks like OpenGL is trying to report some error on Win2003, however you’ve not configured your system where to output logging info. You can add the following to the beginning of your program and you’ll see details of the error in stderr. import logging logging.basicConfig() Checkout documentation on logging module to get more config info, … Read more

How to use glOrtho() in OpenGL?

Have a look at this picture: Graphical Projections The glOrtho command produces an “Oblique” projection that you see in the bottom row. No matter how far away vertexes are in the z direction, they will not recede into the distance. I use glOrtho every time I need to do 2D graphics in OpenGL (such as … Read more

Using OpenGl with C#? [closed]

OpenTK is an improvement over the Tao API, as it uses idiomatic C# style with overloading, strongly-typed enums, exceptions, and standard .NET types: GL.Begin(BeginMode.Points); GL.Color3(Color.Yellow); GL.Vertex3(Vector3.Up); as opposed to Tao which merely mirrors the C API: Gl.glBegin(Gl.GL_POINTS); // double “gl” prefix Gl.glColor3ub(255, 255, 0); // have to pass RGB values as separate args Gl.glVertex3f(0, 1, … Read more

Render OpenGL scene to texture using FBO in fixed function pipeline drawing

When I compared your code with mine working engine I see these differences so try them one by one: texture format you are using: glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, screen_width, screen_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL); so merging all your to: GL_COLOR_ATTACHMENT0: GL_RGBA,GL_RGBA,GL_UNSIGNED_BYTE GL_COLOR_ATTACHMENT1: GL_RGBA,GL_RGBA,GL_UNSIGNED_BYTE I am using: GL_COLOR_ATTACHMENT0 : GL_RGBA , GL_RGBA8 , GL_UNSIGNED_BYTE GL_DEPTH_ATTACHMENT : GL_DEPTH_COMPONENT, … Read more

PyOpenGL how do I import an obj file?

Set the keyword argument collect_faces = True, when you read the Wavefront .obj file. That causes that triangle face data are collected for every mesh.: (See PyWavefront) scene = pywavefront.Wavefront(‘Handgun_obj.obj’, collect_faces=True) Compute the scene box. The vertices are contained in scene.vertices. Each vertex is tuple with 3 components (x, y, z coordinate): scene_box = (scene.vertices[0], … Read more