Contribute to thiagopsilva/Apostila-android development by creating an account on GitHub. Veja grátis o arquivo Apostila PyOpenGL enviado para a disciplina de Sistemas In this new from import * format, we can use OpenGL module commands. in due course. 2. Introduction OpenGL (Open Graphics Library) is a cross- platform, hardware-accelerated, apostila CPA 10 Uploaded by Marcella Costa.

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Apostila PyOpenGL

Some information about Brett Porter: If you haven’t used gluLookAt before, essentially it places the camera at the position of the first 3 parameters, places the center of the scene at the position of the next 3 parameters, and the last 3 parameters describe the vector that is “up”. The Code – Drawing the Model Now we can start the code to draw the model!

You will know when you are using commands from each specific OpenGL module by looking at the first few letters of the OpenGL command. The function must be called first, and after loading the identity to behave in this fashion. When you draw something with OpenGL, you see colors on the screen, but keep in mind that there are other buffers than the color buffer. You should see something that looks similar to Figure 4.

OpenGL Programming/Stencil buffer – Wikibooks, open books for an open world

The def keyword marks the beginning of a function block of code in Python. Note however that it does not preserve the material properties in the same way.

Then the file is read into a temporary buffer in its entirety. It is a binary file, hence the ios:: Press the “End” key on the keyboard or click at the end of this line. This reverses the y coordinate. GLUT preface in a similar fashion as string in the Super-3 program. Model Rendering Tutorial by Brett Porter brettporter yahoo. Lets look at that function now: At the top of the code in Lesson So at this point, the protected member variables of the Model class are filled with the model information.


Another method is to fill the screen using two triangles, and with a stencil test for instance, to match only non-0 stencil pixels. This way each vertex need only be listed once, saving memory and calculations when it comes to animating later. Click on the line that contains the glutInitDisplayMode command.

From Wikibooks, open books for an open world. The import statements add extra functions to this basic set of commands.

Finally there is a new DrawGLScene function: In this program, the display function is def draw. There are several resources on the web that can help you out. And if I get around to it, I will write more loader classes to make the program more versatile.

This doesn’t mean they can’t be used by you – it means that if you cut-and-paste the code into your project, you have to give me proper credit. This is not difficult at all now that we have a careful arrangement of the data structures in memory.

Jeff Molofee’s OpenGL Windows Tutorial #32

In other languages Add links. If you don’t understand much about matrices and vectors, now is the time to read up them!

The texture used is the one applied to this mesh which is described next. It loops through each of the triangles for the mesh, and then draws each of opehgl three vertices, including the normal and texture coordinates. Ditto for if statements and for loops. However, the file format, while it will be described briefly here, is not the major concern for loading a model. Or add them to the scene and draw several models!

OpenGL Programming/Stencil buffer

Now, a pointer is acquired oepngl out current position in the file, pPtr. What doesn’t remain intact are the textures that were bound to texture objects when we loaded the object.


Enviado por Bruno flag Denunciar. You will notice there is a pure virtual function called loadModelData, which takes the filename of the model as an argument. This first part saves the state of texture mapping within OpenGL so that the function does not disturb it.

The next structure we have in a model is a mesh. Also, new memory is allocated for the texture filename, and it is copied into there. In this case, we look from 75, 75, 75 to 0,0,0 – as the model is drawn about 0,0,0 unless you translate before drawing it – and the positive Y-axis is facing up.

First, the file is opened. Remember that each triangle in a mesh and likewise each vertex in a triangle is indexed into the total model arrays these are the two index variables used. A mesh is a group of triangles that all have the same material applied to them. But the model doesn’t need to be reloaded, as its data remains intact. You don’t learn anything with cut-and-paste! If it is set to 0, you’ll recall, there was no texture, so texturing is disabled.

Several calls to memcpy will be used in this function, which copies the contents of the small arrays easily.

A suggestion is to first implement your drawing algorithm using dppass for clarity, and once it works, reverse the conditions in glStencilFunc and use the sfail. So the following line is added to InitGL: Note that there’s no need to use a separate program to draw in the stencil buffer.