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• By elect
Hi,
ok, so, we are having problems with our current mirror reflection implementation.
At the moment we are doing it very simple, so for the i-th frame, we calculate the reflection vectors given the viewPoint and some predefined points on the mirror surface (position and normal).
Then, using the least squared algorithm, we find the point that has the minimum distance from all these reflections vectors. This is going to be our virtual viewPoint (with the right orientation).
After that, we render offscreen to a texture by setting the OpenGL camera on the virtual viewPoint.
And finally we use the rendered texture on the mirror surface.
So far this has always been fine, but now we are having some more strong constraints on accuracy.
What are our best options given that:
- we have a dynamic scene, the mirror and parts of the scene can change continuously from frame to frame
- we have about 3k points (with normals) per mirror, calculated offline using some cad program (such as Catia)
- all the mirror are always perfectly spherical (with different radius vertically and horizontally) and they are always convex
- a scene can have up to 10 mirror
- it should be fast enough also for vr (Htc Vive) on fastest gpus (only desktops)

Looking around, some papers talk about calculating some caustic surface derivation offline, but I don't know if this suits my case
Also, another paper, used some acceleration structures to detect the intersection between the reflection vectors and the scene, and then adjust the corresponding texture coordinate. This looks the most accurate but also very heavy from a computational point of view.

Other than that, I couldn't find anything updated/exhaustive around, can you help me?

• Hello all,
I am currently working on a game engine for use with my game development that I would like to be as flexible as possible.  As such the exact requirements for how things should work can't be nailed down to a specific implementation and I am looking for, at least now, a default good average case scenario design.
Here is what I have implemented:
Deferred rendering using OpenGL Arbitrary number of lights and shadow mapping Each rendered object, as defined by a set of geometry, textures, animation data, and a model matrix is rendered with its own draw call Skeletal animations implemented on the GPU.   Model matrix transformation implemented on the GPU Frustum and octree culling for optimization Here are my questions and concerns:
Doing the skeletal animation on the GPU, currently, requires doing the skinning for each object multiple times per frame: once for the initial geometry rendering and once for the shadow map rendering for each light for which it is not culled.  This seems very inefficient.  Is there a way to do skeletal animation on the GPU only once across these render calls? Without doing the model matrix transformation on the CPU, I fail to see how I can easily batch objects with the same textures and shaders in a single draw call without passing a ton of matrix data to the GPU (an array of model matrices then an index for each vertex into that array for transformation purposes?) If I do the matrix transformations on the CPU, It seems I can't really do the skinning on the GPU as the pre-transformed vertexes will wreck havoc with the calculations, so this seems not viable unless I am missing something Overall it seems like simplest solution is to just do all of the vertex manipulation on the CPU and pass the pre-transformed data to the GPU, using vertex shaders that do basically nothing.  This doesn't seem the most efficient use of the graphics hardware, but could potentially reduce the number of draw calls needed.

Really, I am looking for some advice on how to proceed with this, how something like this is typically handled.  Are the multiple draw calls and skinning calculations not a huge deal?  I would LIKE to save as much of the CPU's time per frame so it can be tasked with other things, as to keep CPU resources open to the implementation of the engine.  However, that becomes a moot point if the GPU becomes a bottleneck.

• Hello!
I would like to introduce Diligent Engine, a project that I've been recently working on. Diligent Engine is a light-weight cross-platform abstraction layer between the application and the platform-specific graphics API. Its main goal is to take advantages of the next-generation APIs such as Direct3D12 and Vulkan, but at the same time provide support for older platforms via Direct3D11, OpenGL and OpenGLES. Diligent Engine exposes common front-end for all supported platforms and provides interoperability with underlying native API. Shader source code converter allows shaders authored in HLSL to be translated to GLSL and used on all platforms. Diligent Engine supports integration with Unity and is designed to be used as a graphics subsystem in a standalone game engine, Unity native plugin or any other 3D application. It is distributed under Apache 2.0 license and is free to use. Full source code is available for download on GitHub.
Features:
True cross-platform Exact same client code for all supported platforms and rendering backends No #if defined(_WIN32) ... #elif defined(LINUX) ... #elif defined(ANDROID) ... No #if defined(D3D11) ... #elif defined(D3D12) ... #elif defined(OPENGL) ... Exact same HLSL shaders run on all platforms and all backends Modular design Components are clearly separated logically and physically and can be used as needed Only take what you need for your project (do not want to keep samples and tutorials in your codebase? Simply remove Samples submodule. Only need core functionality? Use only Core submodule) No 15000 lines-of-code files Clear object-based interface No global states Key graphics features: Automatic shader resource binding designed to leverage the next-generation rendering APIs Multithreaded command buffer generation 50,000 draw calls at 300 fps with D3D12 backend Descriptor, memory and resource state management Modern c++ features to make code fast and reliable The following platforms and low-level APIs are currently supported:
Windows Desktop: Direct3D11, Direct3D12, OpenGL Universal Windows: Direct3D11, Direct3D12 Linux: OpenGL Android: OpenGLES MacOS: OpenGL iOS: OpenGLES API Basics
Initialization
The engine can perform initialization of the API or attach to already existing D3D11/D3D12 device or OpenGL/GLES context. For instance, the following code shows how the engine can be initialized in D3D12 mode:
#include "RenderDeviceFactoryD3D12.h" using namespace Diligent; // ...  GetEngineFactoryD3D12Type GetEngineFactoryD3D12 = nullptr; // Load the dll and import GetEngineFactoryD3D12() function LoadGraphicsEngineD3D12(GetEngineFactoryD3D12); auto *pFactoryD3D11 = GetEngineFactoryD3D12(); EngineD3D12Attribs EngD3D12Attribs; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[0] = 1024; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[1] = 32; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[2] = 16; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[3] = 16; EngD3D12Attribs.NumCommandsToFlushCmdList = 64; RefCntAutoPtr<IRenderDevice> pRenderDevice; RefCntAutoPtr<IDeviceContext> pImmediateContext; SwapChainDesc SwapChainDesc; RefCntAutoPtr<ISwapChain> pSwapChain; pFactoryD3D11->CreateDeviceAndContextsD3D12( EngD3D12Attribs, &pRenderDevice, &pImmediateContext, 0 ); pFactoryD3D11->CreateSwapChainD3D12( pRenderDevice, pImmediateContext, SwapChainDesc, hWnd, &pSwapChain ); Creating Resources
Device resources are created by the render device. The two main resource types are buffers, which represent linear memory, and textures, which use memory layouts optimized for fast filtering. To create a buffer, you need to populate BufferDesc structure and call IRenderDevice::CreateBuffer(). The following code creates a uniform (constant) buffer:
BufferDesc BuffDesc; BufferDesc.Name = "Uniform buffer"; BuffDesc.BindFlags = BIND_UNIFORM_BUFFER; BuffDesc.Usage = USAGE_DYNAMIC; BuffDesc.uiSizeInBytes = sizeof(ShaderConstants); BuffDesc.CPUAccessFlags = CPU_ACCESS_WRITE; m_pDevice->CreateBuffer( BuffDesc, BufferData(), &m_pConstantBuffer ); Similar, to create a texture, populate TextureDesc structure and call IRenderDevice::CreateTexture() as in the following example:
TextureDesc TexDesc; TexDesc.Name = "My texture 2D"; TexDesc.Type = TEXTURE_TYPE_2D; TexDesc.Width = 1024; TexDesc.Height = 1024; TexDesc.Format = TEX_FORMAT_RGBA8_UNORM; TexDesc.Usage = USAGE_DEFAULT; TexDesc.BindFlags = BIND_SHADER_RESOURCE | BIND_RENDER_TARGET | BIND_UNORDERED_ACCESS; TexDesc.Name = "Sample 2D Texture"; m_pRenderDevice->CreateTexture( TexDesc, TextureData(), &m_pTestTex ); Initializing Pipeline State
Diligent Engine follows Direct3D12 style to configure the graphics/compute pipeline. One big Pipelines State Object (PSO) encompasses all required states (all shader stages, input layout description, depth stencil, rasterizer and blend state descriptions etc.)
To create a shader, populate ShaderCreationAttribs structure. An important member is ShaderCreationAttribs::SourceLanguage. The following are valid values for this member:
SHADER_SOURCE_LANGUAGE_DEFAULT  - The shader source format matches the underlying graphics API: HLSL for D3D11 or D3D12 mode, and GLSL for OpenGL and OpenGLES modes. SHADER_SOURCE_LANGUAGE_HLSL  - The shader source is in HLSL. For OpenGL and OpenGLES modes, the source code will be converted to GLSL. See shader converter for details. SHADER_SOURCE_LANGUAGE_GLSL  - The shader source is in GLSL. There is currently no GLSL to HLSL converter. To allow grouping of resources based on the frequency of expected change, Diligent Engine introduces classification of shader variables:
Static variables (SHADER_VARIABLE_TYPE_STATIC) are variables that are expected to be set only once. They may not be changed once a resource is bound to the variable. Such variables are intended to hold global constants such as camera attributes or global light attributes constant buffers. Mutable variables (SHADER_VARIABLE_TYPE_MUTABLE) define resources that are expected to change on a per-material frequency. Examples may include diffuse textures, normal maps etc. Dynamic variables (SHADER_VARIABLE_TYPE_DYNAMIC) are expected to change frequently and randomly. This post describes the resource binding model in Diligent Engine.
The following is an example of shader initialization:
To create a pipeline state object, define instance of PipelineStateDesc structure. The structure defines the pipeline specifics such as if the pipeline is a compute pipeline, number and format of render targets as well as depth-stencil format:
// This is a graphics pipeline PSODesc.IsComputePipeline = false; PSODesc.GraphicsPipeline.NumRenderTargets = 1; PSODesc.GraphicsPipeline.RTVFormats[0] = TEX_FORMAT_RGBA8_UNORM_SRGB; PSODesc.GraphicsPipeline.DSVFormat = TEX_FORMAT_D32_FLOAT; The structure also defines depth-stencil, rasterizer, blend state, input layout and other parameters. For instance, rasterizer state can be defined as in the code snippet below:
// Init rasterizer state RasterizerStateDesc &RasterizerDesc = PSODesc.GraphicsPipeline.RasterizerDesc; RasterizerDesc.FillMode = FILL_MODE_SOLID; RasterizerDesc.CullMode = CULL_MODE_NONE; RasterizerDesc.FrontCounterClockwise = True; RasterizerDesc.ScissorEnable = True; //RSDesc.MultisampleEnable = false; // do not allow msaa (fonts would be degraded) RasterizerDesc.AntialiasedLineEnable = False; When all fields are populated, call IRenderDevice::CreatePipelineState() to create the PSO:
Shader resource binding in Diligent Engine is based on grouping variables in 3 different groups (static, mutable and dynamic). Static variables are variables that are expected to be set only once. They may not be changed once a resource is bound to the variable. Such variables are intended to hold global constants such as camera attributes or global light attributes constant buffers. They are bound directly to the shader object:

m_pPSO->CreateShaderResourceBinding(&m_pSRB); Dynamic and mutable resources are then bound through SRB object:
m_pSRB->GetVariable(SHADER_TYPE_VERTEX, "tex2DDiffuse")->Set(pDiffuseTexSRV); m_pSRB->GetVariable(SHADER_TYPE_VERTEX, "cbRandomAttribs")->Set(pRandomAttrsCB); The difference between mutable and dynamic resources is that mutable ones can only be set once for every instance of a shader resource binding. Dynamic resources can be set multiple times. It is important to properly set the variable type as this may affect performance. Static variables are generally most efficient, followed by mutable. Dynamic variables are most expensive from performance point of view. This post explains shader resource binding in more details.
Setting the Pipeline State and Invoking Draw Command
Before any draw command can be invoked, all required vertex and index buffers as well as the pipeline state should be bound to the device context:
// Clear render target const float zero[4] = {0, 0, 0, 0}; m_pContext->ClearRenderTarget(nullptr, zero); // Set vertex and index buffers IBuffer *buffer[] = {m_pVertexBuffer}; Uint32 offsets[] = {0}; Uint32 strides[] = {sizeof(MyVertex)}; m_pContext->SetVertexBuffers(0, 1, buffer, strides, offsets, SET_VERTEX_BUFFERS_FLAG_RESET); m_pContext->SetIndexBuffer(m_pIndexBuffer, 0); m_pContext->SetPipelineState(m_pPSO); Also, all shader resources must be committed to the device context:
m_pContext->CommitShaderResources(m_pSRB, COMMIT_SHADER_RESOURCES_FLAG_TRANSITION_RESOURCES); When all required states and resources are bound, IDeviceContext::Draw() can be used to execute draw command or IDeviceContext::DispatchCompute() can be used to execute compute command. Note that for a draw command, graphics pipeline must be bound, and for dispatch command, compute pipeline must be bound. Draw() takes DrawAttribs structure as an argument. The structure members define all attributes required to perform the command (primitive topology, number of vertices or indices, if draw call is indexed or not, if draw call is instanced or not, if draw call is indirect or not, etc.). For example:
DrawAttribs attrs; attrs.IsIndexed = true; attrs.IndexType = VT_UINT16; attrs.NumIndices = 36; attrs.Topology = PRIMITIVE_TOPOLOGY_TRIANGLE_LIST; pContext->Draw(attrs); Tutorials and Samples
The GitHub repository contains a number of tutorials and sample applications that demonstrate the API usage.

AntTweakBar sample demonstrates how to use AntTweakBar library to create simple user interface.

Atmospheric scattering sample is a more advanced example. It demonstrates how Diligent Engine can be used to implement various rendering tasks: loading textures from files, using complex shaders, rendering to textures, using compute shaders and unordered access views, etc.

The repository includes Asteroids performance benchmark based on this demo developed by Intel. It renders 50,000 unique textured asteroids and lets compare performance of D3D11 and D3D12 implementations. Every asteroid is a combination of one of 1000 unique meshes and one of 10 unique textures.

Integration with Unity
Diligent Engine supports integration with Unity through Unity low-level native plugin interface. The engine relies on Native API Interoperability to attach to the graphics API initialized by Unity. After Diligent Engine device and context are created, they can be used us usual to create resources and issue rendering commands. GhostCubePlugin shows an example how Diligent Engine can be used to render a ghost cube only visible as a reflection in a mirror.

• By Yxjmir
I'm trying to load data from a .gltf file into a struct to use to load a .bin file. I don't think there is a problem with how the vertex positions are loaded, but with the indices. This is what I get when drawing with glDrawArrays(GL_LINES, ...):

Also, using glDrawElements gives a similar result. Since it looks like its drawing triangles using the wrong vertices for each face, I'm assuming it needs an index buffer/element buffer. (I'm not sure why there is a line going through part of it, it doesn't look like it belongs to a side, re-exported it without texture coordinates checked, and its not there)
I'm using jsoncpp to load the GLTF file, its format is based on JSON. Here is the gltf struct I'm using, and how I parse the file:
glBindVertexArray(g_pGame->m_VAO);
glDrawElements(GL_LINES, g_pGame->m_indices.size(), GL_UNSIGNED_BYTE, (void*)0); // Only shows with GL_UNSIGNED_BYTE
glDrawArrays(GL_LINES, 0, g_pGame->m_vertexCount);
So, I'm asking what type should I use for the indices? it doesn't seem to be unsigned short, which is what I selected with the Khronos Group Exporter for blender. Also, am I reading part or all of the .bin file wrong?
Test.gltf
Test.bin

• That means how do I use base DirectX or OpenGL api's to make a physics based destruction simulation?
Will it be just smart rendering or something else is required?

# OpenGL directx and win graphics future(opinion)

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I don't know... I think DirectX is here to stay. At least until (lots of) people abandon windows, which probably won't happen in the near future.

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Graphics/Game programming existed before DirectX and it will exist after DirectX is dead (probably a good while from now). Too many people seem to think that DirectX IS game programming. Don't concern yourself with the API, concern yourself with learning/using the concepts.

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So that this doesn't turn into a DX vs. OpenGL flamewar, it should be stated up front that both DirectX and OpenGL are constantly being upgraded. The difference is that most of the upgrades to OpenGL happen through vendor-specific extensions rather than through some central authority.

Technology, be it graphics cards, CPU's, or even that used in television sets, is continuously updated. If someone wants to take advantage of the latest and greatest advancements in technology, they will have to keep up with the products based on these technologies.

That being said, even AAA quality games, such as Half-Life 2 and Doom 3, that take advantage of the latest and greatest hardware available will also support less technologically advanced hardware. As game developers, we all know that not every player will spend US\$500.00 every year on a graphics card. Therefor, while we strive to take advantage of the newest technology available, we also make our products flexible enough so that they perform well on less advanced hardware.

It is rarely the case that someone needs to buy new hardware every year just to keep up with the latest games unless the graphics card you upgrade to is currently a "value" card. For example, if you upgrade right now to a Geforce 4, chances are you'll need a newer graphics card in a year or so if you want to play the latest games on the highest quality settings, reguardless of whether that game uses DirectX or OpenGL to render the scenes.

neneboricua

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Quote:
 Opengl is gaining terrain

My DirectX engine has had terrain for 2 years!

And I doubt more people buy Macs because they are hard to upgrade, and must be "thrown away". You can easily get the same effect by buying a PC and never upgrading it.

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Quote:
 Graphics/Game programming existed before DirectX and it will exist after DirectX is dead (probably a good while from now). Too many people seem to think that DirectX IS game programming. Don't concern yourself with the API, concern yourself with learning/using the concepts.

Microsoft, via Windows, is putting a huge amount of resources and effort into DirectX - and it's offshoot in the form of XBox/XBox360..

Yes, I'm sure something bigger and better will appear in years (decades?) to come... but it's incredibly unlikely to happen overnight.

Till then you are simply left with a couple of choices. Not everyone has the same goals/values, so not everyone is expected to pick the same choice.

If the Windows platform, along with it's particular customer base and market share suit what you need, then go for it.

If you want to target the mobile-phone market, handheld market, linux or mac market's then you choose differently (e.g. go with OpenGL).

Quote:
 speaking of stability almost any other operating system is more stable then windows.

I just want to be a bit picky here: Do you have anything to back this statement up?

If not, you should drop it. I read these sorts of comments a lot, and it's rare to find any conclusive evidence/support for said comments. I've been running Windows XP Professional for several years now. There are only two occurences where it's ever been unstable - when I break it (e.g. bad programming) or when I do something that would take most OS's down (e.g. user error). In both of those situations I've never crashed anything more than the application I'm currently using - I've never taken the whole system down with it (like happened in Win9x [wink])...

Cheers,
Jack

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i think windows is the most primitive operating system.
Linux is more stable,os x for mac's is more professional and never crashes.
For example if you open more programs in windows it works extremely slow and to many viruses and dirty stuff get in your computer no matter what protection.. for example i use bit defender 8 professional and 2 firewalls and i still get ad ware stuff in my computer..
Soon i will turn to linux.. and never use windows xp.

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Quote:
 Original post by Raxvani think windows is the most primitive operating system.Linux is more stable,os x for mac's is more professional and never crashes.For example if you open more programs in windows it works extremely slow and to many viruses and dirty stuff get in your computer no matter what protection.. for example i use bit defender 8 professional and 2 firewalls and i still get ad ware stuff in my computer..Soon i will turn to linux.. and never use windows xp.

I think the most primitive operating systems are the multitudes which fly around on the internet, a.k.a. hobby operating systems. It's true Windows 98 and everything prior exhibited, well - let's say frequent crashes, but to be fair that a) has been resolved with Windows XP and later, and b) was due to the fact that Microsoft were pinoneering operating system development with Windows 95 (I don't care how much GUI they stole from Apple, a lot of stuff in 95 was innovative, even if it was internal and buggy). You could say that the people who developed Linux had a good guide of how not to build an operating system, and good luck to them. I truly hope we get some cross-platform OS competition going, and with Apple moving to Intel, and Linux beginning to become Joe-Bloggs friendly, I think the golden age of operating systems will be upon us shortly. /Idealistic ideas.

On topic: I think Simian Man said it best: Regardless of what API you learn/program with, you're going to have to know the underlying concepts, otherwise you're not going to get anywhere professionally. As it is, nVidia and ATI are both providing cards with DirectX and OpenGL support for shaders, etc, and I don't think there even needs to be another contender, as people are still 3 years behind cutting-edge technology as it is. As for DirectX being proprietary (sp?), that may dictate the direction that DirectX moves in, but Microsoft isn't going to get anywhere without full documentation and a full-featured, professional API. Which means if trends in game development crop up, it's a safe bet to say that the next version of DirectX will reflect those trends; the same goes for OpenGL (as it's dictated by developers). I think it will be a long time before DirectX kicks it, at which point a lot of people are going to realise that the code they copy and pasted from the internet is useless, and they're going to have to learn what mipmapping and a Flexible Vertex Format actually are. Who even knows if OpenGL will even exist then, and quite frankly, who cares? 3D graphical APIs are basically mathematics wrapped in a helpful package, and you're not going to get anywhere without knowing the maths.

Phew, that came out a little more heated than expected - it could be because I'm a little tipsy... in fact that is why is it... so take it with a pinch of salt. I like to think I've been pretty even handed about it.

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Quote:
 Original post by Raxvani think windows is the most primitive operating system.Linux is more stable,os x for mac's is more professional and never crashes.For example if you open more programs in windows it works extremely slow and to many viruses and dirty stuff get in your computer no matter what protection.. for example i use bit defender 8 professional and 2 firewalls and i still get ad ware stuff in my computer..Soon i will turn to linux.. and never use windows xp.

If you are having problems with installing a simple firewall and scanning your system for viruses, I would *love* to see you try to administer a Linux box for any duration of time. I guess if you switched though, you wouldn't have any use for this DirectX forum anymore...isn't that a shame.

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Quote:
 Original post by RaxvanSome friends of mine say that is you want to upgrade a mac just trow the old one out and buy another one.Opengl is gaining terrain and i think soon directx will be history not because of performance because it works on most of the computers no mater what operating system.

Quite the contary, as many of the content creation packages now support Direct3D, and the PC gaming market has moved to a vast DirectX majority ever since the release of 7/8. Maybe you should get your facts straight before trying to make assumptions based on them.

Quote:
 For example if you open more programs in windows it works extremely slow and to many viruses and dirty stuff get in your computer no matter what protection.. for example i use bit defender 8 professional and 2 firewalls and i still get ad ware stuff in my computer..

Maybe on a crap machine... because I've never tried.. but daily I have about 2 copies of Visual Studio open, Project, Office, Visio, IRC, a few Firefox, and I don't experience any of this 'extremely slow' behavior.

And the spyware issue you have seems to be more between the keyboard and chair than anything quite honestly.