I would like to know how to create 'cylinder effect', like the top site feature in safari 4, here is a picture
http://www.macworld.com/article/139022/2009/02/safari4firstlook.html
Can you tell me what should i learn , how to get started?
I would start by working through the OpenGL tutorials on NeHe's website. You might also want to invest in the Red Book. Topics you'll be interested in: Geometry and texture mapping. I think NeHe even has an example of texture mapping on a cylinder.
Depending on what you hope to accomplish, you might be able to use the Visualization Toolkit to draw a texture on a cylinder in 100 lines of code or less. There's a bit of a learning curve to VTK (and OpenGL for that matter), but the vtkTextureMapToCylinder class and the TCL example of how to use it are good places to get started.
Please download iCarousel. It has many types of cylindrical effects in it.Use whichever is useful for you.
Related
I'm wondering if anyone could point me to any resources that would deal in rotating one or several 2D textured planes in 3D space. Something like this but with openGL (preferably C++):
I'm attempting to do pretty much the exact same thing but no matter how I order my operations I'm getting right-screwy results. So I figure asking for some resources on the subject is better than posting tons of code and asking for people to fix my problems for me. :)
If you havent already, do a search for 'NeHe tutorials'. An excellent set of OpenGL tutorials.
Here is a link to the rotation tutorial, includes all the source code in downloadable format and the tutorial walks you through each relevant line.
http://nehe.gamedev.net/tutorial/rotation/14001/
I believe this is working in a 2D space, the step up to 3D probably involves a bit more matrix math but...doable
The NeHe tutorials are a very popular place to learn the basics of OpenGL. In particular, the tutorial about texture mapping should help you:
http://nehe.gamedev.net/tutorial/texture_mapping/12038/
Mind you though that these tutorials are written for older OpenGL versions which are more beginner friendly IMHO.
You should look into scene graphs. Basically it is a way to define a bunch of objects (2D textured planes) and their transforms in 3D space. This allows you to define transforms that work on multiple nodes (objects) as well as single nodes. You can make a pretty simple one in C++ with little effort, or use one such as OpenSG or OSG (slight learning curve needed).
Wikipedia - http://en.wikipedia.org/wiki/Scene_graph
I'm new to graphics, and I have to make a model of a building for an assignment using only GLUT or OpenGL.
Basically the school building's model( only the exterior portion) is to be made, and I have no clue where to start. Upto now I have drawn polygons, other shapes using GLUT, nothing in which there are multiple shapes. All the drawing upto now is using lines, or points, or polygons and mathematics.
Could you please give me an idea of how to go about it?
Update: I just want to know what steps I can follow to get it done. Some reference links would be awesome!
You could use modeling programs to create your model, and then use tools such as COLLADA to get your model into OpenGL.
The problem with hand-coding a complex object like that is that it takes a great number of lines of code just to define the vertices of the object.
People usually use 3D modeler software to build complex 3D objects, like Maya, 3DSMax or Blender and then export them in a format to be read into your OpenGL application.
Think about what you want your building to look like, and think about what kind of triangles you need to render in order to make that. You can either draw the entire thing in some sort of modelling software, and then import it into OpenGL, or you can come up with the triangles/textures yourself and do it by hand in OpenGL.
The exterior of the building will probably have a similar texture on the whole thing (brick, etc), and then there will be windows, doors, and a roof. Maybe some sort of sign that says "School Building". Take this all into account, what exactly you want your building to look like, and then think about what textures you will need to draw these things.
For example, say you're doing a brick building that is in the shape of a box, with a door and a few windows. I'd use one texture for the brick, and first draw an entire wall of brick. Then, I'd use a grey/blue looking texture for the window, and draw it over the brick wall. Then I'd do the same (different texture) for the door.
Just think about the design, and then just try things out - experiment. Good luck!
I once had a simillar homework. I did it by creating the models with Google SketchUp, then export the models to .3ds file and use my program to render it.
I choose Google SketchUp because it's the easiest to use among those tool I tried. Plus, they had a discount for students. You could also use Blender, which is free but take too much time to learn IMHO. 3dsMax is too expensive to pay for a homework.
To load the model into my program, I used Assimp library.
I need to graph XYZ coordinates in a 3D cube that I can rotate. Im look for code that will basically take a 3d array of 1s and 0s and build a cube. Coloring of the points would also be nice. The program that creates the point is in C/C++ so I would prefer something that would play nicely will that but Im not picky. Im alright aware that Mathematica can do this , but Im looking for something that can be "live" updated so I can watch the progress
Thanks in advance
One obvious possibility would be something like Direct3D (for Windows, X-box and Windows Phone 7) or OpenGL (for pretty much anything that can do 3D except X-box or Windows Phone 7).
There are quite a few libraries and sample code for things like this.
If you're working on Unix/Linux, you may or may not have OpenGL installed. If you don't, you might want to check into Mesa3D.
I would go with Jerry's suggestion of using OpenGL. There are some good tutorials out there too - have a look at the nehe series which have examples for doing precisely what you're after.
Refer this tutorial link : http://www.directxtutorial.com/
This will help you to implement three dimensional cube.
Just learning the basics of OpenGL for a class and was looking for something challenging and interesting to try and draw. Any suggestions?
Aiming to photorealism (just plain models, lights, materials, textures, etc.) is one thing, but what is even more interesting in my opinion is demoscene and all kinds of non-photorealistic effects. The idea of a demo is to program some nice animated graphics that automatically change from one effect to another or tell some sort of a story, and have a background music. Here you can find some videos. Just take a look at what some others have done and use your imagination. That's the funniest part of 3D programming in my opinion. Of course what you'll first program would be something extremely simple when compared to those videos on youtube, but everyone has to start from somewhere. Simple also doesn't need to be ugly. Some random suggestions:
mathematical shapes with sin(), cos(), etc.
alpha blending, especially addition blending (glBlendFunc(GL_ONE, GL_ONE);)
terrain rendering
read 3d model data from a file. (Wavefront .OBJ is a relatively simple one)
feedback effects with glCopyTexImage2D, which copies pixels from screen to a texture (in real life you shouldn't use this because it's too slow, but when learning the basics it's ok)
etc...
You might consider building an OBJ viewer. You will get the experience you're looking for, and it's a pretty good project for a beginning 3D graphics programmer, in terms of difficulty.
I believe opengl has built in shapes such as a teapot that you can call and have it draw. For starters, I'd stick with easy shapes like squares, circles, and cones. Try drawing a wireframe model first since that's the easiest, by using either quadstrips ,triangles or just poly lines. After you've gotten that down, learn to set up lighting and materials so you can draw a solid model.
At school we had a very interesting assignement to get started with OpenGL that I will share. The long term goal was to modelize a living room so you basically have to draw:
A table.
Two chairs.
A carpet.
A sofa
Some stuff that you might find interesting to add on the table for
instance a TV!
When you have all the things done, try to polish the scene a little bit by adding some lighting effects!
Hint: for all the objects you simply need to start with a basic rectangle. Then you can construct your scene step by step using translations/rotations.
I want to ask what is the easiest way to make shadow and light volume ? How can I bring to scene more realism? Do you know any nice tricks ? I hear that to make shadow i must use stencil buffer, but I don't know how:/ I can't find any super simple example how to make it.
There's no super simple way to do shadows. Sorry to disappoint you but shadows are one of the more complex problems in computer graphics, especially if they have to look good.
Now with that said here are some maybe helpful links for further reading:
The Theory of Stencil Shadow Volumes
Shadow Mapping with Today's OpenGL Hardware
Real-time Shadow Algorithms and Techniques
There's a simple example of shadow mapping in the NVIDIA SDK 9 here (Paper) which might be easy to adopt. There's also a section on shadows in all volumes of GPU Gems and a good overview in the Real-Time Rendering book (without code).
The Wolfire blog has had some good articles on shadows. Nothing too technical, no code samples, but to get a good overview of the concepts, they are great (and I love the pictures that always accompany the articles!).
Here is a full list of every article with "shadow" or "shadows" in the title. You may also choose to do a search on their blog for "shadow|shadows" to see every possible article, but beyond this list you probably won't find too much. Might also want to add "-alpha" so that you don't get any hits from their weekly alpha updates, which wouldn't have any worthwhile content.
2006/05/10: Starting shadows
2006/05/18: More shadows
2008/11/24: High-detail terrain shadows
2008/12/02: Object shadows
2009/03/29: Environment shadows - step 1
2009/04/03: Environment shadows - step 2
2009/04/07: Environment shadows - step 3
2009/04/10: Environment shadows - step 4
2009/11/13: Character shadows
2010/03/17: Two-part shadow maps
2010/04/19: Catching baked shadows
(list gathered 2010/05/19 by a google search for site:blog.wolfire.com intitle:shadow|shadows)
These questions are not easy to answer here, it'll require you some study and understanding of how graphic primitives works. However, there are some good sites over the web you can take a look, like Nehe and GameDev. There are lots of articles and tutorials there, just take some time to search and read them. There is also some rendering engines that you can use that will do a lot of nice things for you, like Ogre3d and Irrlicht but if you cant understand the principles behind them (like shadows, illumination...), I recomend you to try in OpenGL first, learn it, and then use some engine to get the work done for you.
In addition to the other useful sources mentioned here, you should consider getting an introductory text on linear algebra, or Eric Lengyel's excellent Mathematics for 3D Game Programming and Computer Graphics, Second Edition. Computer graphics are made of math, and at some level it gets really hard to implement things out of a cookbook without some understanding of the underlying algebra.