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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 Textures not working (CgFX + OpenGL): draws black silhoette (works ok in FXComposer)

This topic is 3557 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

Hi all, My first CgFX application is giving me trouble. I've managed to get some very simple shaders working but am having a lot of trouble passing textures to it. I'm trying to make use of existing libs (namely NVidia's nv::Image for loading the image data from file). The shader works fine in FX Composer (2.5b). The code is clean enough and should be logging all errors (using 'cgGetLastErrorString()' and 'glGetError()' etc). Shading appears is ok when I don't use the texture. But as soon as the texture is used, the CgFX shader compiles without warning and runs without error... but the test sphere I'm trying to draw is a black circle (which my arcball manipulator spins without any trouble). Can anyone suggest why when I use the following code all I see is a black circle? I've been chipping away at this for days (i hate to admit though it's becoming weeks...). can someone please put me out of my misery... even if it looks ok... any opinions/suggestions much a appreciated.
// simpleTextured.cgfx

// This is C2E1v_green from "The Cg Tutorial" (Addison-Wesley, ISBN
// 0321194969) by Randima Fernando and Mark J. Kilgard.  See page 38.

float4x4 modelViewProj : WorldViewProjection < string UIWidget="None"; >;

float3 globalAmbient : Ambient    = { 0.1, 0.1, 0.1 };
float3 lightColor : Specular <
string UIName =  "Lamp 0";
string Object = "Pointlight0";
string UIWidget = "Color";
> = {1.0f,1.0f,1.0f};
float3 lightPosition : Position <
string Object = "PointLight0";
string UIName =  "Lamp 0 Position";
string Space = "World";
> = {0.81,-3.65,5};
float3 eyePosition   : Position   = { 0, 0, 13 };
float3 Ke : Emissive < string UIWidget = "Color"; > = {0.0, 0.0, 0.0};
float3 Ka : Ambient  = {0.0, 0.0, 0.0};
float3 Kd : Diffuse  = {0.5, 0.0, 0.0};
float3 Ks < string UIWidget = "Color"; > = {0.7, 0.6, 0.6};
float  shininess <
string UIWidget = "slider";
float UIMin = 0.0;
float UIMax = 100.0;
float UIStep = 1.0;
string UIName =  "Specular";
> = 32.0;

//////// COLOR & TEXTURE /////////////////////

texture ColorTexture  <
string ResourceName = "default_color.dds";
string UIName =  "Diffuse Texture";
string ResourceType = "2D";
>;

sampler2D ColorSampler = sampler_state {
Texture = <ColorTexture>;
MinFilter = LinearMipMapLinear;
MagFilter = Linear;
WrapS = Repeat;
WrapT = Repeat;
};

// This is C5E2v_fragmentLighting from "The Cg Tutorial" (Addison-Wesley, ISBN
// 0321194969) by Randima Fernando and Mark J. Kilgard.  See page 124.

void main(float4 position : POSITION,
float3 normal   : NORMAL,
float2 uv : TEXCOORD0,
out float4 oPosition : POSITION,
out float2 oUV : TEXCOORD0,
out float3 objectPos : TEXCOORD1,
out float3 oNormal   : TEXCOORD2)
{
oPosition = mul(modelViewProj, position);
objectPos = position.xyz;
oNormal = normal;
oUV = uv;
}

// This is C5E3f_basicLight from "The Cg Tutorial" (Addison-Wesley, ISBN
// 0321194969) by Randima Fernando and Mark J. Kilgard.  See page 125.

void psLight(float4 position  : TEXCOORD0,
float2 uv : TEXCOORD1,
float3 normal    : TEXCOORD2,
out float4 color     : COLOR)
{
float3 P = position.xyz;
float3 N = normalize(normal);

// Compute emissive term
float3 emissive = Ke;

// Compute ambient term
float3 ambient = Ka * globalAmbient;

// Compute the diffuse term
float3 L = normalize(lightPosition - P);
//float diffuseLight = max(dot(L, N), 0);
float3 diffuseLight = tex2D(ColorSampler, uv) + max(dot(L, N), 0);
float3 diffuse = Kd * lightColor * diffuseLight;

// Compute the specular term
float3 V = normalize(eyePosition - P);
float3 H = normalize(L + V);
float specularLight = pow(max(dot(H, N), 0), shininess);
if (diffuseLight <= 0) specularLight = 0;
float3 specular = Ks * lightColor * specularLight;

color.xyz = emissive + ambient + diffuse + specular;
color.w = 1;
}

technique NewTechnique <
string Script = "Pass=p0;";
> {
pass p0 <
string Script = "Draw=geometry;";
> {
VertexProgram = compile vp40 main();
DepthTestEnable = true;
CullFaceEnable = false;
BlendEnable = false;
DepthFunc = LEqual;
FragmentProgram = compile fp40 psLight();
}
}


//  Initialize() CPP

cgContext = cgCreateContext();
LOG_CG("cgCreateContext", cgContext);
cgVertexProfile = cgGLGetLatestProfile(CG_GL_VERTEX);
cgFragmentProfile = cgGLGetLatestProfile(CG_GL_FRAGMENT);
cgGLSetOptimalOptions(cgVertexProfile);
cgGLSetOptimalOptions(cgFragmentProfile);
LOG_CG("cgGLSetOptimalOptions", cgContext);
LOG("Cg Vertex Profile:   " << cgGetProfileString(cgVertexProfile));
LOG("Cg Fragment Profile: " << cgGetProfileString(cgFragmentProfile));

PathResolver pathResolver("");
//const std::string cgFXFile = "phong.cgfx";
//const std::string cgFXFile = "green.cg";
//const std::string cgFXFile = "vertlight.cgfx";
const std::string cgFXFile = "blinn.cgfx";
std::string resolvedCgFXFile = "";
if (pathResolver.getFilePath(cgFXFile, resolvedCgFXFile))
{
cgProgram = cgCreateProgramFromFile(cgContext, CG_SOURCE, resolvedCgFXFile.c_str(), cgVertexProfile, "main", 0);
LOG_CG("cgCreateProgramFromFile(" << resolvedCgFXFile << ")", cgContext);
}
else

const std::string modelFile = "cow.obj";
std::string resolvedModelFile = "";
if (pathResolver.getFilePath(modelFile, resolvedModelFile))
else

if(cgProgram == 0)
{
LOG_ERROR("Invalid Cg program. This program will now exit...");
exit(1);
}

cgGLRegisterStates(cgContext);
LOG_CG("cgGLRegisterStates", cgContext);
cgGLSetManageTextureParameters(cgContext, CG_TRUE);
LOG_CG("cgGLSetManageTextureParameters", cgContext);
cgEffect = cgCreateEffectFromFile(cgContext, resolvedCgFXFile.c_str(), NULL);
LOG_CG("cgCreateEffectFromFile(" << resolvedCgFXFile << ")", cgContext);

cgTechnique = cgGetFirstTechnique(cgEffect);
while (cgTechnique && cgValidateTechnique(cgTechnique) == CG_FALSE)
{
LOG_ERROR("Technique '" << cgGetTechniqueName(cgTechnique) << "' did not validate");
cgTechnique = cgGetNextTechnique(cgTechnique);
}

LOG_CG("CG Techniques initialise", cgContext);

if (cgTechnique) {
LOG("Using Cg technique '" << cgGetTechniqueName(cgTechnique) << "' from '" << cgFXFile << "'.");
} else {
}

// Load the texture (if needed)
CGparameter param = cgGetNamedParameter(cgProgram, "ColorSampler");
LOG_CG("cgGetNamedParameter", cgContext);
if (param != 0) {
cgGLEnableTextureParameter(param);

image = new nv::Image();
const std::string texFile = "Default_color.dds";
std::string resolvedTexFile = "";
if (!(pathResolver.getFilePath(texFile, resolvedTexFile) &&

LOG("Texture loaded (" << resolvedTexFile << ")");

GLuint texName;
glGenTextures(1, &texName);
glBindTexture(GL_TEXTURE_2D, texName);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri( GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_FALSE);
glTexImage2D( GL_TEXTURE_2D, 0, image->getInternalFormat(), image->getWidth(), image->getHeight(), 0, image->getFormat(), image->getType(), image->getLevel(0));
LOG_OGL("glTexImage2D()");

cgGLSetTextureParameter(param, texName);
LOG_CG("cgGLSetTextureParameter(param, texName)", cgContext);
}
else
LOG("WARNING: No texture parameter found. Expecting 'sampler2D ColorSampler'.");

cgGLEnableProfile(cgVertexProfile);
cgGLEnableProfile(cgFragmentProfile);


//  Display() in CPP
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
manipulator.applyTransform();

CGparameter param = 0;
param = cgGetEffectParameterBySemantic(cgEffect, "WorldViewProjection");
if (param != 0)
cgGLSetStateMatrixParameter(param, CG_GL_MODELVIEW_MATRIX, CG_GL_MATRIX_IDENTITY);
LOG_CG("cgGLSetStateMatrixParameter(WorldViewProjection)", cgContext);

cgGLBindProgram(cgProgram);
CGpass pass = cgGetFirstPass(cgTechnique);
while (pass) {
cgSetPassState(pass);

//DrawModel(model, modelBBMin, modelBBMax);
glutSolidSphere(0.5, 8, 8);
cgResetPassState(pass);
pass = cgGetNextPass(pass);
}
glutSwapBuffers();


[Edited by - axon on June 16, 2008 12:40:29 AM]

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Well like you may have gathered from my other thread you replied to, my understanding of Cg is not great, but theres something there I have never seen before: you don't pass the sampler2D into the pixel shader, you access it globally. I didn't know this was possible! Maybe you could try:
void psLight(float4 position  : TEXCOORD0,             float2 uv : TEXCOORD1,             float3 normal    : TEXCOORD2,             uniform sampler2D : colorSampler,             out float4 color     : COLOR){  ...  float3 diffuseLight = tex2D(colorSampler, uv) + max(dot(L, N), 0);  ...}technique NewTechnique <	string Script = "Pass=p0;";> {    pass p0 <	string Script = "Draw=geometry;";    > {        VertexProgram = compile vp40 main();		DepthTestEnable = true;		DepthMask = true;		CullFaceEnable = false;		BlendEnable = false;		DepthFunc = LEqual;        FragmentProgram = compile fp40 psLight(ColorSampler);    }}

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Quote:
 Original post by bluntmanWell like you may have gathered from my other thread you replied to, my understanding of Cg is not great, but theres something there I have never seen before: you don't pass the sampler2D into the pixel shader, you access it globally. I didn't know this was possible! Maybe you could try:*** Source Snippet Removed ***

Thanks for the suggestion. Unfortunately what you've noticed is one of the differences between Cg and CgFX. In Cg you pass samplers and other variables to the shader methods as uniforms. In CgFX you can (should?/must?) declare them as globals. (I just had a look at a few FXComposer shaders and they're all handling the sampler in the same way as the above code.)

Any other suggestions?
Maybe my OpenGL code is wrong? (I worked from the latest OpenGL Bible (6th ed) but I guess I could still have missed something???

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Well I am using CgFx in my current project and I pass everything as uniforms from the globals. It makes more sense that way, what if your vertex and fragment shaders are in different source files? I don't think CgFx resolves like that. I have never used FxComposer, but all the CgFx examples I have seen, including those in the Cg 2.0 users manual show all variables passed as uniforms. e.g. page 123 from the CgUsersManual.pdf that comes with the Cg2.0 SDK.

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Just gave it a try using the following shader but I get the same result.
/*********************************************************************NVMH3****$Revision$Copyright NVIDIA Corporation 2007TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, THIS SOFTWARE IS PROVIDED*AS IS* AND NVIDIA AND ITS SUPPLIERS DISCLAIM ALL WARRANTIES, EITHER EXPRESSOR IMPLIED, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITYAND FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL NVIDIA OR ITS SUPPLIERSBE LIABLE FOR ANY SPECIAL, INCIDENTAL, INDIRECT, OR CONSEQUENTIAL DAMAGESWHATSOEVER (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS,BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR ANY OTHER PECUNIARYLOSS) ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IFNVIDIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.To learn more about shading, shaders, and to bounce ideas off other shader    authors and users, visit the NVIDIA Shader Library Forums at:    http://developer.nvidia.com/forums/******************************************************************************/// #define FLIP_TEXTURE_Yfloat Script : STANDARDSGLOBAL <    string UIWidget = "none";    string ScriptClass = "object";    string ScriptOrder = "standard";    string ScriptOutput = "color";    string Script = "Technique=Main;";> = 0.8;//// UN-TWEAKABLES - AUTOMATICALLY-TRACKED TRANSFORMS ////////////////float4x4 WorldITXf : WorldInverseTranspose < string UIWidget="None"; >;float4x4 WvpXf : WorldViewProjection < string UIWidget="None"; >;float4x4 WorldXf : World < string UIWidget="None"; >;float4x4 ViewIXf : ViewInverse < string UIWidget="None"; >;//// TWEAKABLE PARAMETERS /////////////////////// Point Lamp 0 ////////////float3 Lamp0Pos : Position <    string Object = "PointLight0";    string UIName =  "Lamp 0 Position";    string Space = "World";> = {-0.5f,2.0f,1.25f};float3 Lamp0Color : Specular <    string UIName =  "Lamp 0";    string Object = "Pointlight0";    string UIWidget = "Color";> = {1.0f,1.0f,1.0f};// Ambient Lightfloat3 AmbiColor : Ambient <    string UIName =  "Ambient Light";    string UIWidget = "Color";> = {0.07f,0.07f,0.07f};float Ks <    string UIWidget = "slider";    float UIMin = 0.0;    float UIMax = 1.0;    float UIStep = 0.05;    string UIName =  "Specular";> = 0.4;float Eccentricity <    string UIWidget = "slider";    float UIMin = 0.0;    float UIMax = 1.0;    float UIStep = 0.0001;    string UIName =  "Highlight Eccentricity";> = 0.3; //////// COLOR & TEXTURE /////////////////////texture ColorTexture  <    string ResourceName = "default_color.dds";    string UIName =  "Diffuse Texture";    string ResourceType = "2D";>;sampler2D ColorSampler = sampler_state {    Texture = <ColorTexture>;    MinFilter = LinearMipMapLinear;    MagFilter = Linear;    WrapS = Repeat;    WrapT = Repeat;};  //// #define this macro to permit the import and use of shared shadow//  maps created by COLLADA-FX. Make sure that the macro is defined//  and the code recompile *before* executing "Convert to Collada-FX"!//// #define USE_SHARED_SHADOW#ifdef USE_SHARED_SHADOW#include "include/shadowMap.cgh"DECLARE_SHADOW_XFORMS("SpotLight0",LampViewXf,LampProjXf,ShadowViewProjXf)DECLARE_SHADOW_BIASDECLARE_SHADOW_MAPS(ColorShadTarget,ColorShadSampler,DepthShadTarget,DepthShadSampler)float ShadDens <    string UIWidget = "slider";    float UIMin = 0.0;    float UIMax = 1.0;    float UIStep = 0.01;    string UIName =  "Shadow Density";> = 0.7;#endif /* USE_SHARED_SHADOW *///////// CONNECTOR DATA STRUCTURES ////////////* data from application vertex buffer */struct appdata {    float3 Position	: POSITION;    float4 UV		: TEXCOORD0;    float4 Normal	: NORMAL;    float4 Tangent	: TANGENT0;    float4 Binormal	: BINORMAL0;};/* data passed from vertex shader to pixel shader */struct vertexOutput {    float4 HPosition	: POSITION;    float2 UV		: TEXCOORD0;    // The following values are passed in "World" coordinates since    //   it tends to be the most flexible and easy for handling    //   reflections, sky lighting, and other "global" effects.    float3 LightVec	: TEXCOORD1;    float3 WorldNormal	: TEXCOORD2;    float3 WorldTangent	: TEXCOORD3;    float3 WorldBinormal : TEXCOORD4;    float3 WorldView	: TEXCOORD5;#ifdef USE_SHARED_SHADOW    // This optional value expresses the current location in "light"    //   coordinates for use with shadow mapping.    float4 LProj	: LPROJ_COORD;#endif /* USE_SHARED_SHADOW */}; ///////// VERTEX SHADING //////////////////////*********** Generic Vertex Shader ******/vertexOutput main(appdata IN) {    vertexOutput OUT = (vertexOutput)0;    OUT.WorldNormal = mul(WorldITXf,IN.Normal).xyz;    OUT.WorldTangent = mul(WorldITXf,IN.Tangent).xyz;    OUT.WorldBinormal = mul(WorldITXf,IN.Binormal).xyz;    float4 Po = float4(IN.Position.xyz,1);    float3 Pw = mul(WorldXf,Po).xyz;    OUT.LightVec = (Lamp0Pos - Pw);#ifdef FLIP_TEXTURE_Y    OUT.UV = float2(IN.UV.x,(1.0-IN.UV.y));#else /* !FLIP_TEXTURE_Y */    OUT.UV = IN.UV.xy;#endif /* !FLIP_TEXTURE_Y */#ifdef USE_SHARED_SHADOW    float4 Pl = mul(ShadowViewProjXf,Pw);  // "P" in light coords    float4x4 BiasXf = make_bias_mat(ShadBias);    OUT.LProj = mul(BiasXf,Pl);		// bias to make texcoord#endif /* USE_SHARED_SHADOW */    OUT.WorldView = normalize(float3(ViewIXf[0].w,ViewIXf[1].w,ViewIXf[2].w) - Pw);    OUT.HPosition = mul(WvpXf,Po);    return OUT;}///////// PIXEL SHADING //////////////////////// Utility function for blinn shadingvoid blinn_shading(vertexOutput IN,		    float3 LightColor,		    float3 Nn,		    float3 Ln,		    float3 Vn,			uniform sampler2D colorSampler,		    out float3 DiffuseContrib,		    out float3 SpecularContrib){    float3 Hn = normalize(Vn + Ln);    float hdn = dot(Hn,Nn);    float3 R = reflect(-Ln,Nn);    float rdv = dot(R,Vn);    rdv = max(rdv,0.001);    float ldn=dot(Ln,Nn);    ldn = max(ldn,0.0);    float ndv = dot(Nn,Vn);    float hdv = dot(Hn,Vn);    float eSq = Eccentricity*Eccentricity;    float distrib = eSq / (rdv * rdv * (eSq - 1.0) + 1.0);    distrib = distrib * distrib;    float Gb = 2.0 * hdn * ndv / hdv;    float Gc = 2.0 * hdn * ldn / hdv;    float Ga = min(1.0,min(Gb,Gc));    float fresnelHack = 1.0 - pow(ndv,5.0);    hdn = distrib * Ga * fresnelHack / ndv;    DiffuseContrib = ldn * LightColor;    SpecularContrib = hdn * Ks * LightColor;}float4 std_PS(vertexOutput IN,              uniform sampler2D colorSampler) : COLOR {    float3 diffContrib;    float3 specContrib;    float3 Ln = normalize(IN.LightVec);    float3 Vn = normalize(IN.WorldView);    float3 Nn = normalize(IN.WorldNormal);	blinn_shading(IN,Lamp0Color,Nn,Ln,Vn,colorSampler,diffContrib,specContrib);    float3 diffuseColor = tex2D(ColorSampler,IN.UV).rgb;#ifdef USE_SHARED_SHADOW    float shadowed = tex2Dproj(DepthShadSampler,IN.LProj).x;	float faded = 1.0-(ShadDens*(1.0-shadowed));	diffContrib *= faded;	specContrib *= shadowed;#endif /* USE_SHARED_SHADOW */    float3 result = specContrib+(diffuseColor*(diffContrib+AmbiColor));    // return as float4    return float4(result,1);}///// TECHNIQUES /////////////////////////////technique Main <	string Script = "Pass=p0;";> {    pass p0 <	string Script = "Draw=geometry;";    > {        VertexProgram = compile vp40 main();		DepthTestEnable = true;		DepthMask = true;		CullFaceEnable = false;		BlendEnable = false;		DepthFunc = LEqual;        FragmentProgram = compile fp40 std_PS(ColorSampler);    }}/////////////////////////////////////// eof //

I also tried setting the texParam explicitely per-frame (in Display()) but alas... no joy :(

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You say when you try and render with the texture the sphere appears as a black circle? Do you mean completely black, from all angles, i.e. no specular or ambient? If it was just the texture that was not being set correctly then I would still expect to see specular.
Are you sure glutSphere function generates UVs? Maybe you need to enable automatic texture coord generation?

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You're right, the specular term should be there but it isn't. The sphere is absolute black when viewed from every direction. Well spotted :)

So maybe it isn't the ColourSampler (or possibly even nothing to do with the texture)?

Looks like it could be the transforms after all.

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What happens when you keep everything the same but remove the texture diffuse component from the final calculation?
like:
float3 diffuse = Kd * lightColor;
float3 diffuse = Kd * lightColor * diffuseLight;
The only way I can think of that the a problem with the texture could cause the final colour to always be completely black is if there is a NaN value getting in there somewhere, but afaik if the texture is not set then it will return zeros not NaNs.

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Hi Axon, I saw your post on the NVIDIA forums.

I'm having similar issues, with probably the world's simplest CgFX shader. At first I thought it was a problem using Cg with Qt, but turns out it isn't.

Try using this as a test:

float4 Diffuse : COLOR<	string UIWidget = "Color";	string UIName =  "Diffuse";>  = {0.8f, 0.8f, 0.8f, 1.0f};sampler2D DiffuseSampler = sampler_state{	MinFilter = LinearMipMapLinear;};float4x4 WorldViewProj : WORLDVIEWPROJECTION;struct VInput{	float4 Position : POSITION;	float4 Colour : COLOR0;	float2 UVCoord 	: TEXCOORD0;};struct VOutput{	float4 Position : POSITION;	float4 Colour : COLOR0;	float2 UVCoord : TEXCOORD0;};VOutput VShader(VInput IN){	//Create output object	VOutput OUT;		//Calculate output position	OUT.Position = mul(WorldViewProj, IN.Position);	OUT.UVCoord = IN.UVCoord;	OUT.Colour = Diffuse;		return OUT;}float4 PShader(VOutput IN) : COLOR{	return tex2D(DiffuseSampler, IN.UVCoord);;}technique Main{	pass p0	{		VertexProgram = compile vp40 VShader();		DepthTestEnable = true;		DepthMask = true;		CullFaceEnable = true;		BlendEnable = false;		DepthFunc = LEqual;		FragmentProgram = compile fp40 PShader();	}}

Let's see if we can sort this out, there must be a common problem with our code, see mine here for reference: http://www.gamedev.net/community/forums/topic.asp?topic_id=497585

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We're in the same boat... let's make it float.

I've had this problem for, I hate to admit it, possibly over 2 months.

I'm supposed to be good at this gear. I am good at this gear. I've read a lot of documentation including the thin PDF examples (which do all kinds of non-conventional stuff w.r.t geometry and textures) combed the PDFs. The SDK samples (both Cg/Cg-toolkit SDK and NV OpenGL SDK) and re-created some of their demos.

So where are we up to?:
1. Transforms and verts are ok. (Since your shader in the prev post uses only WorldViewProj and renders black geometry ok).
2. Shader is ok. Works in FXComposer (after you add the Texture param so that FXComposer can hook in (that could be a clue... but none of the demos seem to need to touch the Texture param)).
3. UVs are ok. (Since tex2D(sampler, float2(0.5,0.5)) returns green (center pix color of texture) in FXComposer but returns black in my app.)

I'm tempted to grab their CgFX bumdemo and start to piecewise convert it.
Step 1: Convert it to use own geom and test
Step 2: Convert it to use own tex and test
Step 3: Convert it to use own CgFX and test

Theoretically that can't go wrong... it's be great to think the solution is closer than that (since i've already done similar approaches before).

Or is it something curlier like we're linking against beta dlls at run-time???

I'll def keep this post updated... glad not to be alone on this one. I have tried for so long to figure it out methodically (as you obviously have) and yet here we are.

EDIT:
@bluntman: I rekon deadstar's shader distills the problem down. tex2D(sampler, uv) returns zeros (black) when it should look up the texture. I've also tested tex2D(sampler, float2(0.5,0.5)) and in FXComposer it returns green (from center of texture) and in my app it returns black.

[Edited by - axon on June 17, 2008 10:22:35 PM]