Need help with Shallow Water Ripples effect in XNA - xna

I need to create a water-like surface in XNA, viewed from above.
Like this :
http://www.youtube.com/watch?v=Nr42AG1aPAY
Can someone point me to some examples?
I don't know where to start.
Thanks,
SW.

This is a common request which is demonstrated for most programming environments. You can find lots of resources online by simply doing a search for water ripple shader:
http://www.bing.com/search?q=water+ripple+shader
You'll probably find lots of non-xna versions (for example), but if it's an hlsl shader it should be simple to port it to xna since it supports those directly on both windows and the xbox.

Related

Web application framework that suports 3D

I have an idea to develop a website that would help people to model 3D worlds, use 3D models and so on.
For example, based on my reseach, I could use Unity Framework to create this type of application for PC/MAC.
I am wondering if there are similar frameworks available for pure WEB?
This is my first time looking into this and I do not have any expertize in this topic. Please advise if you have any opinions or expertise in it.
Unity indeed has support for 3d on web, but it requires from user that it has installed Unity player. Users might not like that.
However, with webGL, you would have absolute control over the look and capabilities of your product, users wouldn't have to install anything new, it would all be pure web and only IE users would be damaged, because IE still doesn't have full support for webGL.
To develop with webGL you can do it from scratch, or you could use some of the existing libraries/3D engines that would speed up your work and give results much faster.
Here's a list of webGL engines: http://ffwd.typepad.com/blog/2011/04/webgl-what-flavor-is-your-engine.html, it seems that most used are Three.js, Scene.js and there is also Goo Engine (http://www.gooengine.com/).
Hope this helps.
Check out 3DTin, it does seem to deliver a part of what you want to build, using WebGL:
http://www.3dtin.com/

3D library recommendations for interactive spatial data visualisation?

Our software produces a lot of data that is georeferenced and recorded over time. We are considering ways to improve the visualisation, and showing the (processed) data in a 3D view, given it's georeferenced, seems a good idea.
I am looking for SO's recommendations for what 3D libraries are best to use as a base when building these kind of visualisations in a Delphi- / C++Builder-based Windows application. I'll add a bounty when I can.
The data
Is recorded over time (hours to days) and is GPS-tagged. So, we have a lot of data following a path over time.
Is spatial: it represents real 3D elements of the earth, such as the land, or 3D elements of objects around the earth.
Is high volume: we could have a point cloud, say, of hundreds of thousands to millions of points. Processed data may display as surfaces created from these point clouds.
From that, you can see that an interactive, spatially-based 3D visualisation seems a good approach. I'm envisaging something where you can easily and quickly navigate around in space, and data will load or be generated on the fly depending on what you're looking at. I would prefer we don't try to write our own 3D library from scratch - for something like this, there have to be good existing libraries we can work from.
So, I'm hoping for a library which supports:
good navigation (is the library based on Euler rotations only, for example? Can you 'pick' objects to rotate around or move with easily?);
modern GPUs (shader-only rendering is ok; being able to hook into the pipeline to write shaders that map values to colours and change dynamically would be great - think data values given a colour through a colour lookup table);
dynamic data / objects (data can be added as it's recorded; and if the data volume is too high, we should be able to page things in and out or recreate them, and only show a sensible subset so that whatever the user's viewport is looking at is there onscreen, but other data can be loaded/regenerated, preferably asynchronously, or at least quickly as the user navigates. Obviously data creation is dependent on us, but a library that has hooks for this kind of thing would be great.)
and technologically, works with Delphi / C++Builder and the VCL.
Libraries
There are two main libraries I've considered so far - I'm looking for knowledgeable opinions about these, or for other libraries I haven't considered.
1. FireMonkey
This is Embarcadero's new UI library, which is only available in XE2 and above. Our app is based on the VCL and we'd want to host this in a VCL window; that seems to be officially unsupported but unofficially works fine, or is available through third-parties.
The mix of UI framework and 3D framework with shaders etc sounds great. But I don't know how complex the library is, what support it has for data that's not a simple object like a cube or sphere, and how well-designed it is. That last link has major criticisms of the 3D side of the library - severe enough I am not sure it's worthwhile in its current state at the time of writing for a non-trivial 3D app.
Is it worth trying to write a new visualisation window in our VCL app using FireMonkey?
2. GLScene
GLScene is a well-known 3D OpenGL framework for Delphi. I have never used it myself so have no experience about how it works or is designed. However, I believe it integrates well into VCL windows and supports shaders and modern GPUs. I do not know how its scene graph or navigation work or how well dynamic data can be implemented.
Its feature list specifically mentions some things I'm interested in, such as easy rotation/movement, procedural objects (implying dynamic data is easy to implement), and helper functions for picking. It seems shaders are Cg only (not GLSL or another non-vendor-specific language.) It also supports "polymorphic image support for texturing (allows many formats as well as procedural textures), easily extendable" - that may just mean many image formats, or it may indicate something where the texture can be dynamically changed, such as for dynamic colour mapping.
Where to from here?
These are the only two major 3D libraries I know of for Delphi or C++Builder. Have I missed any? Are there pros and cons I'm not aware of? Do you have any experience using either of these for this kind of purpose, and what pitfalls should we be wary of or features should we know about and use?
We currently use Embarcadero RAD Studio 2010 and most of our software is written in C++. We have small amounts of Delphi and may consider upgrading IDEs, but we are most likely to wait until the 64-bit C++ compiler is released. For that reason, a library that works in RS2010 might be best.
Thanks for your input :) I'm after high-quality answers, so I'll add a bounty when I can!
I have used GLScene in my 3D geomapping software and although it's not used to an extent you're looking for I can vouch that it seems the most appropriate for what you're trying to do.
GLScene supports terrain rendering and adding customizable objects to the scene. Objects can be interacted with and you can create complex 3D models of objects using the various building blocks of GLScene.
Unfortunately I cannot state how it will work with millions of points, but I do know that it is quite optimized and performs great on minimal hardware - that being said - the target PC I found required a dedicated graphics card capable of using OpenGL 2.1 extensions or higher (I found small issues with integrated graphics cards).
The other library I looked at was DXscene - which appears quite similar to GLScene albeit using DirectX instead of OpenGL. From memory this was a commercial product where GLScene was licensed under GPL. (EDIT - the page seems to be down at the moment : http://www.ksdev.com/index.html)
GLScene is still in active development and provides a fairly comprehensive library of functions, base objects and texturing etc. Things like rotation, translation, pitch, roll, turn, ray casting - to name a few - are all provided for you. Visibility culling is provided for each base object as well as viewing cameras, lighting and meshes. Base objects include cubes, spheres, pipes, tetrahedrons, cones, terrain, grids, 3d text, arrows to name a few.
Objects can be picked with the mouse and moved along 1,2 or 3 axes. Helper functions are included to automatically calculate the top-most object the mouse is under. Complex 3D shapes can be built by attaching base objects to other base objects in a hierarchical manner. So, for example, a car could be built using a rectangle as the base object and attaching four cylinders to it for the wheels - then you can manipulate the 'car' as a whole - since the four cylinders are attached to the base rectangle.
The only downside I could bring to your attention is the sometimes limited help/support available to you. Yes, there is a reference manual and a number of demo applications to show you how to do things such as select objects and move them around, however the reference manual is not complete and there is potential to get 'stuck' on how to accomplish a certain task. Forum support is somewhat limited/sparse. If you have a sound knowledge of 3D basics and concepts I'm sure you could nut it out.
As for Firemonkey - I have had no experience with this so I can't comment. I believe this is more targeted at mobile applications with lower hardware requirements so you may have issues with larger data sets.
Here are some other links that you may consider - I have no experience with them:
http://www.truevision3d.com/
http://www.3impact.com/
Game Development in Delphi
The last one is targeted at game development - but may provide useful information.
Have you tried glData? http://gldata.sourceforge.net/
It is old (~2004, Delphi 7), and I have not personally used the library, but some of the output is amazing.
you can use the GLScene or OpenGL they are good 3D rendering and its very easy to use.
Since you are already using georeferenced data, maybe you should consider embedding GoogleEarth in your Delphi application like this? Then you can add data to it as points, paths, or objects.

OpenCV and Computer Vision, where do we stand now?

I want to do a project involving Computer Vision. Mostly object detection/identification. After some research, I keep coming back to OpenCV. But all of the tutorials are from 2008 (I guess it was big for a bit then). It doesn't compile in Python on the mac apparently. I'm using the C++ framework right out of Xcode, but none of the tutorials work as they're outdated and the documentation sucks from what I can parse.
Is there a better solution for what I'm doing, and does anyone have any suggestions as to learning how to to use OpenCV?
Thanks
I have had similar problems getting started with OpenCV and from my experience this is actually the biggest hurdle to learning it. Here is what worked for me:
This book: "OpenCV 2 Computer Vision Application Programming Cookbook." It's the most up-to-date book and has examples on how to solve different Computer Vision problems (You can see the table of contents on Amazon with "Look Inside!"). It really helped ease me into OpenCV and get comfortable with how the library works.
Like have others have said, the samples are very helpful. For things that the book skips or covers only briefly you can usually find more detailed examples when looking through the samples. You can also find different ways of solving the same problem between the book and the samples. For example, for finding keypoints/features, the book shows an example using FAST features:
vector<KeyPoint> keypoints;
FastFeatureDetector fast(40);
fast.detect(image, keypoints);
But in the samples you will find a much more flexible way (if you want to have the option of choosing which keypoint detection algorithm to use):
vector<KeyPoint> keypoints;
Ptr<FeatureDetector> featureDetector = FeatureDetector::create("FAST");
featureDetector->detect(image, keypoints);
From my experience things eventually start to click and for more specific questions you start finding up-to-date information on blogs or right here on StackOverflow.
Let me add a couple of things. First, I can assure you that the Python bindings to OpenCV work on a Mac. I use them every day.
Many people like OpenCV for many reasons:
The license is good, friendly to integration into commercial products, etc.
It is quite good from a technical stand point. It gives you a reference implementation of state of the art algorithms.
It tends to be quite fast compared to the alternatives (Matlab I'm looking at you).
Like everything in life, it is not perfect:
It is a good example of a software library that is a moving target.
I have a 300 line python program that uses OpenCV and every few
months when a new version of OpenCV is released I have to change it
to adapt to the new function names/calling conventions, etc. The
library does advance, a lot, however it is a pain to have to change
the same program 3 times per year.
It has a learning curve, like computer vision itself, it is quite
technical and not easy to learn.
There are alternatives (with other pros and cons) MATLAB with the Image Processing Toolbox is one such example.
The simplest answer that comes to mind, is to read the example code with a bit of understanding, and to try out if Your ideas work. The api does change, and most of the tutorials are writen for the first versions of OpenCV, and it looks that nobody bothered to rewrite them. Nevertheless the core ideas behind it are not changing. So if You find a tutorial answering Your questions, but written in old API just look in the documentation for modern replacements of used functions. It’s not easy and quick, but looks like it works. If You use the newest (actually 2.3) version, I suggest using both the 2.1 documntation and 2.3 docs + tutorials . You should also look into the samples, which should have been installed alongside the library. There are lots of hints about how to use certain structures and tricks that weren't mentioned in documentation. Finally, don't be afraid to look inside the code of the library itself (if You compiled it on Your own). Unfortunately, thats the only source I know to check for example what code corresponds to which type of Mat object.

Done Some 2D Game Design, Now Want To Move To 3D

I have used PyGame for a while now, and quite enjoyed doing so, but only 2D experience is not going to cut it when I apply for video game jobs, and besides, I have a number of ideas I want to try out in 3D. What 3D library should I go into first? I was considering Irrlicht, which will also force me to work on my C++ again, but I was also looking towards XNA, as it would be cool to write 360 games. Any suggestions?
You can try Unity3D http://unity3d.com/. In the fall they released their engine for free that is cross platform (Mac, Win and possible Linux) and it can also be targeted for iPhone and web browser and is starting to build an open community and looks promising.
I've done some XNA stuff and the Unity tools look pretty good in comparison making it easier to get content into your games.
In my opinion, going with Irrlicht or OGRE is a good idea. It will help you get back in touch with C++ and experiment with 3D without making it too easy. It is a good idea to learn XNA as well and build a few 3D game prototypes there.
Summary: Do both, eventually. Learn OpenGL/DirectX later.
All the best.
XNA Game Studio is a fantastic framework and let's users jump into creating games quite quickly if you are comfortable with the .NET Framework.
However, if you decide that you want to move to the 3D world, you have 1 more dimension to take into consideration and it makes things exponentially harder. Simple collision detection, isn't so simple anymore. However, with the vast amount of information available for XNA Game Studio, you should find yourself getting to grips with the 3rd dimension quite quickly.
If you haven't done the whole Nehe type tutorials, it's probably best to play with the API, so that you get comfortable with it.
Create a Triangle
Spin the Triangle
Color the Triangle
Load some assets (models and textures) and render them
Try your hand at Alpha Blending
Take into consideration that XNA Game Studio does not have a fixed function pipeline and you will have to use Shaders (HLSL).
I have personally used Irrlicht, Ogre3d, Unity & Xna. Because you want to do this to help for when you apply for jobs in the game industry in my opinion I would suggest Irrlicht as you will want to work on your c++ skills. I also suggest Irrlicht as it is a 3D engine not a specific game engine which will allow you to work on your physics and maths skills as well which are highly sought after in the games industry.
I would suggest avoiding Unity if you are looking for experience to take to industry as it is a package that handles a lot for you and as such could limit your learning.
Ogre3D is a viable option as it is similar to Irlicht, maybe look into the tools available to help you make a choice between those two.
Xna is another interesting choice, it will give you a lot of chances to learn as Irrlicht could and there are a huge amount of resources to help you learn but at the same time you lose the c++ experience that comes with irrlicht.

DirectX 9 or DirectX 10 for starters?

I want to do projects to make my resume more appealing to game companies. So I am going to start buying books. But I don't know rather to read DirectX 9 or 10 api books to start off with. DirectX10 is great, but it seems the industry is moving slow to 10. so should I use 9 or go with 10 ??
I would suggest learning the basics using directx9 and then rapidly moving on to dx11. DirectX11 is harder to get started in than DirectX9 because it's slightly more complex but also a lot of the utility functions in D3DX are no longer there, or have been moved to source code like the effects framework. This is no bad thing, but it does make it signifiacantly more complex to learn as you have to learn a lot more things at once.
Spend 2 or 3 weeks learning DX9 then move to DX11 for "real" work :P
Learn basic DX9 using the fixed pipeline and d3dx for loading models etc. It's a lot simpler than DX11 and much better documented, and you'll get a triangle and then a model on screen very much faster. Play with that until you completely understand the basic concepts and tranformations.
But then rewrite it all using shaders only. You'll need to use them in DX10/11 anyway but it's a lot easier to learn when you already have a working framework of code, and it's a lot simpler to get that working in DX9.
Once you have that working, learn DX11. You'll have to switch math libraries. You'll have to invent your own model formats and loaders. You'll have to either invent your own effects framework or use the example one, but they are all much easier now you already know the basics of 3d and programming shaders.
TBH further to OneOfOne's comment if you know how to do 3D development in GL, D3D9, D3D10 or D3D11 then you can transfer those skills to any of the others with a little bit of work.
Personally I'd aim for D3D11 as that way you are learning the cutting edge. You'll find you'll be able to do GL, D3D9 or D3D10 with a little work. Do enough work on the theory and you'll discover that its not even that hard to transfer the skills to a fully software engine.
If your intention is really to learn a skill that you would use in the game industry, stick with DirectX 9. Since DirectX 10 and 11 both require Vista or Window 7, game developers are still mostly ignoring them and targeting DirectX 9 in order to have support for Windows XP.
That being said, it doesn't really matter which you start with. The differences are not that large. If you understand the concepts behind 3D APIs and how the GPU pipeline works, you can pick up any of the three or even OpenGL with minimal effort.
Fact is, you need to learn both.
As long as 50% of gamers are still on WinXP, you're going to need to be able to program in Direct3D9.
D3D9 isn't any easier to get started with than D3D10/11. Its the same principles, with vertices to be placed, normals to be calculated, and meshes to be rendered. Whether you're creating a ID3D11BlendState structure or calling IDirect3DDevice9::SetRenderState(), its the same concept, just different ways of doing it.
After working with d3d11 a couple of days, I've come to think of it as better than DX9 in a lot of ways. For one, you're able to use the full caps of the GPU including geometry shaders. 2nd, it forces you to fully understand the graphics pipeline to even draw anything (note how functions are named after the stage of the pipeline they affect: here: (IA* fcns: input-assembler stage, OM* fcns: output-merger stage etc) ). This may result in a slightly larger INITIAL startup curve, but once you get it, its not any harder than D3D9 and is better, since the very naming of the functions helps concepts stick.
So get going on both, and learning them in tandem may help reduce the amount of effort you spend learning deprecated API's/methods of doing things from DX9 (ie you really want to spend more time using shaders, and don't use the fixed function pipeline section of DX9 too much).
You can check Luna's books for DX9 /DX11(I suggest you start with 11). You can check out http://www.rastertek.com/tutdx11.html but he doesn't explain everything so you can go in Luna s book to see what is with those functions or properties
With some little exceptions, DX10 is just a legacy free DX9. For example DX9 had build in options for rendering Flatshaded, Textured or using a Shader. In DX10 these options are gone, you always have to use a real shader. If you want to do flatshading, write a HLSL shader that does flat shading.
So I would suggest you learn DX10 (or DX11). You will be able to adopt fast to DX9 but with a more modern coding style by not using legacy functions. They can be quiet confusing, so DX10 will focus you on relevant things.
If you are a real beginner, and setting up a vertex-buffer to create a single triangle is confusing you (as real 3D-Programmer you are no more interesten in single triangles) I even would suggest to start with OpenGL. You will have faster success, but in reality this can be a little bit distracting as DX9-Legacy if you want to focus on modern 3D-Coding.
Yes do not waste your time with DX10 it was never really adopted as the industry standard for any period of time, there wasn't any big enough changes to warrant people upgrading from DX9 but for DX11 there was.
I suggest directx 11, there's no reason in my opinion to waste time on deprecated functions or techniques.
Learning shaders from the start will make things way more clear
Try doing the samples from the sample folder of both 9 and 10, and if your computer can support it, 11. This is what I am doing.

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