I am at a crossroads between using OpenGL ES 1.1 and 2.0 for iPhone development. I plan on creating 2D applications and simple 3D applications. In the interest of simplicity, should I use 1.1? Or will this be discontinued at some point in iOS? I would like to know if the shaders in 2.0 are significantly more beneficial in making simple programs than the shaders in 1.1. Please tell me the advantages of each. Thanks.
I would say the definitive reason the use 2.0 starting out is complex effects, 2.0 is a wild card in this matter, shaders are little bits of software that run inside the graphics card (ok, not always true) and have the ability to affect individual pixels at run time. In 1.1 there's a lot you can do, but most of the time you're affecting all the pixels in the texture, to affect individual pixels, you have to combine textures, and the after a while there's just stuff you can't do in 1.1.
Now if you don't need complex effects, you can start and use 1.1, but let me show you your journey:
In the beginning 1.1 will be easier, glTranslatef, glRotatef, glScalef, etc do save you time and allow you to start manipulating objects easily.
But has you progress and start to do more complex things, you learn about matrix manipulations, say there's a routine that's a bit slow because you're doing a lot of tranlastes, rotates, etc. So you read up on the subject and learn you can combine all those operations into one matrix, so you start doing your own matrix calc funcs and start to use glMultMatrixf more, after a while it's just easier to always glMultMatrixf, because you can latter add stuff without having to rewrite code.
At this point you have no reason to use 1.1, going from glMultMatrixf to 2.0 is a very small step, and you get that whole new world from the shaders.
So, if you don't need big effects and are itching to go, alright use 1.1.
Anything else just go direct to 2.0.
Disclaimer
Yes this is a simplification, but a journey i've made myself.
2.0 has a programmable pipeline
This seems like not very much information (as when i first started i was like "uh ok?") but it really means a lot.
In allowing you to take control of the transformations of vertices
Now in the smaller things I have done (3d) the transformations could easily be managed by 1.1 automatically, but it is cool to have total control over them in 2.0
If you're learning opengles on the idevices i suggest making programs at first that support both 1.1 and 2.0 so you can get even more experience and understanding into opengles
If you need full control over the vertices then 2.0 is the way to go, otherwise 1.1 should be fine
Related
I'm creating a simple Breakout style game and would like a simple way to display the score.
I've been doing some research and found several ways to do text in OpenGL ES, but most methods look fairly complicated.
This looks like it would do the trick, but I couldn't get it to work.
I've looked into FTGL and FreeType, but they look complicated.
I've also read one can display a UILabel over the EAGLContext, but not sure how that would be in the performance department.
I could probably get any of these options to work, I'm just wondering what the best solution is for this situation.
For simple use cases like you're describing, on even vaguely modern hardware (i.e. iPhone 3GS and later, I think), the compositing penalty for layering UIKit/CoreAnimation content on top of OpenGL ES content is negligible. (You can see this if you run your app in Instruments with the "Color OpenGL ES fast path blue" option turned on.)
They say premature optimization is the root of all evil — it's pretty easy to try UILabel, see if it makes a significant difference to your app's performance, and look into third-party libraries and more complicated solutions only if it does.
(Also, it sounds like you might be trying to manage your own CAEAGLLayer. For common use cases, it's a lot easier to use GLKView, plus GLKViewController for animation.)
I'd recommend checking out the Print3D functionality of the PowerVR SDK's PVRTools framework. Print3D is free to use, cross-platform (iOS, Android, Linux, Windows, OS X etc.) and it efficiently renders text within OpenGL ES 1.x, 2.0 & 3.0 applications. The SDK includes an example application with source that demonstrates how to use the Print3D framework (IntroducingPrint3D).
The PowerVR Graphics SDK can be downloaded for free from Imagination's website: http://www.imgtec.com/powervr/insider/sdkdownloads/index.asp
An overview of the source included in the SDK can be found here: http://www.imgtec.com/powervr/insider/sdkdownloads/learn_more.asp
Context
I am building this multiplayer D&D encounter tool (in C# for WinRT) which is a simple 2D grid based utility where each player can control their character with the DM being able to control the whole environment as well as mobs etc. I decided to use DirectX (through the SharpDX wrapper) as opposed to standard XAML elements (which would probably handle this scenario too) mainly to learn DirectX and possibly to achieve better performance on lower spec PCs (not sure how XAML would handle thousands of sprites on the screen).
Question
Since I am new to DirectX I was wondering what is the best* way to draw the sprites (characters, props, background tiles, etc)?
*By best I mean in terms of performance and GPU memory requirements. My aim is to have this tool to run well even on low spec ARM tablets and I have no idea how demanding each approach is.
Currently I am using the Direct2D BitmapSourceEffect and load each sprite batch using the WIC API. Another approach which I also encountered in various DirectX books is described in this SO question: What is the best pratice[sic] to render sprites in DirectX 11?
Using the BitmapSourceEffect seems to be easier but is it the right tool to do the job? I plan to compare the two approaches later today (in terms of FPS, rendering a large number of sprites), but perhaps you guys can provide more insight into this matter. Thanks!
I am working on an image processing app for the iOS, and one of the various stages of my application is a vector based image posterization/color detection.
Now, I've written the code that can, per-pixel, determine the posterized color, but going through each and every pixel in an image, I imagine, would be quite difficult for the processor if the iOS. As such, I was wondering if it is possible to use the graphics processor instead;
I'd like to create a sort of "pixel shader" which uses OpenGL-ES, or some other rendering technology to process and posterize the image quickly. I have no idea where to start (I've written simple shaders for Unity3D, but never done the underlying programming for them).
Can anyone point me in the correct direction?
I'm going to come at this sideways and suggest you try out Brad Larson's GPUImage framework, which describes itself as "a BSD-licensed iOS library that lets you apply GPU-accelerated filters and other effects to images, live camera video, and movies". I haven't used it and assume you'll need to do some GL reading to add your own filtering but it'll handle so much of the boilerplate stuff and provides so many prepackaged filters that it's definitely worth looking into. It doesn't sound like you're otherwise particularly interested in OpenGL so there's no real reason to look into it.
I will add the sole consideration that under iOS 4 I found it often faster to do work on the CPU (using GCD to distribute it amongst cores) than on the GPU where I needed to be able to read the results back at the end for any sort of serial access. That's because OpenGL is generally designed so that you upload an image and then it converts it into whatever format it wants and if you want to read it back then it converts it back to the one format you expect to receive it in and copies it to where you want it. So what you save on the GPU you pay for because the GL driver has to shunt and rearrange memory. As of iOS 5 Apple have introduced a special mechanism that effectively gives you direct CPU access to OpenGL's texture store so that's probably not a concern any more.
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.
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.