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About germangb

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  1. VBOs and transformation matrices

      What If I want to update the geometry? (add/remove vertices to the VBO)   And If I have, let's say, lots of small sprites (textured quads/triangles), a single VBO for each of them doesn't look like a good idea...
  2. Hello, I have been reading about the topic of VBOs and how they will benefit my rendering. But I don't understand how you can use the typical transformation matrices to transform data that is held in a VBO.   For example, let's say I have a VBO storing all the geometry of my scene, including a cube that rotates/moves independently from the rest of the geometry.   I want to render the geometry held in the VBO but I also want to apply a transformation to the cube that is inside.   What's a good approach to do that? Do I apply the transformation to the vertices and then put the vertex information of the cube with the transformation applied, updating the VBO in every single frame?   I'd want to be able to apply the transformation with a vertex shader, but I don't see the way to do that.   thanks.
  3. This might be a silly question, but I've seen her in many graphics programming articles and I'm keen on using its 3d model...     thanks :)
  4. alpha maps?

    I've seen that by increasing the resolution of the alpha map, the path gets smoother, but I have to increase it a lot...
  5. alpha maps?

    Hello, I have this mesh:   and I was wondering how to draw a path so that the plane would look like this (with smooth borders):       What I have been able to do so far is this.   and as you can see, it's such a fail. I don't know what to do to make it smooth.
  6. people in the GTA Chinatown Wars game look like 2d sprites but they are 3d models, here are some screenshots of the game:   I believe this kind of models can be archieved by defining the models with 3d points intead of polygons, and then render a tiny square for each point in the 3d scene.   Any ideas?
  7. texture issue

    I have two 2D textured quads that always face me: [img][/img] It looks ok, but when I watch the 2 quads from another point I have the following problem: [img][/img] any idea?
  8. terrain render

    [quote name='L. Spiro' timestamp='1355307587' post='5009771'] If your question is purely about whether or not viewport clipping is supported with each of these rendering methods, the answer is Yes. Viewport clipping is part of the rendering pipeline and it makes no difference how the triangles got to that stage of the pipeline. But we can’t tell you in good conscience to use immediate mode nor display lists. Immediate mode has been deprecated for ages and is terribly horribly slow. Display lists have been deprecated for a shorter period of time but are deprecated and their use is entirely discouraged not only by people who know what they are doing but also by Khronos. Considering how easy the switch is to VBO’s from display lists, there really is no reason not to do it, so I really can’t understand why you can’t just use VBO’s and be done with it. In future versions of OpenGL you won’t even have the choice not to use VBO’s—it will be required that you do. L. Spiro [/quote] thanks! I'll definitely go with VBOs
  9. terrain render

    [quote name='L. Spiro' timestamp='1355195961' post='5009289'] Using immediate mode makes slow. It is [b]never[/b] “okay” to use immediate mode. Use VBO’s. L. Spiro [/quote] yeah I know, but what about displaylists instead of VBOs?
  10. terrain render

    [quote name='Steve_Segreto' timestamp='1355168680' post='5009169'] Yes. viewport clipping still works in immediate mode IIRC. [/quote] won't it make the framerate drop drastically?
  11. terrain render

    Hey, I want to implement clipping in my terrain generator in openg. The question is: would it be ok to use inmediate mode to perform the render?
  12. triangles and textures (2D)

    hello @Goran Milovanovic, thank you very much for the reply!! I've just realized how easy it is to implement by just dividing the vertex coordinates by the size of the texture.
  13. Projectile Motion (Parabola)

    a parabolic throw consists of 2 movements: vertical (accelerated because of gravity) and horizontal (constant). That way, if you're working with pixels, you could simulate the action of gravity by adding some value to the vertical velocity in every frame, wich should point upwards at the begining.
  14. triangles and textures (2D)

    Hello, I've been hanging around these forums for like a month or so, sience I started with the game programming stuff, but anyways... I have the 2d map made of triangles: [img][/img] and the following texture (this is just an example, so the size of the image is not a power of 2): [img][/img] My question is: is there any opengl method to make the map look like this directly: [img][/img] or I have to specify the texture coordinates "manually"? Any reply is appreciated, many thanks.