mix the vsgHelloworld example and vsgImgui

[Conan42]

Hello Robert,

I'm trying to mix the vsgHelloworld example and vsgImgui, but I'm stuck on the commandGraph:

auto commandGraph = createCommandGraphForView(window, camera, sceneGraph);

// auto renderGraph = vsg::RenderGraph::create(window);
// commandGraph->addChild(renderGraph);

// Create the ImGui node and add it to the renderGraph

// auto params = Params::create();
// auto renderImGui = vsgImGui::RenderImGui::create(window, MyGui::create(params, options));
// renderGraph->addChild(renderImGui);

viewer->assignRecordAndSubmitTaskAndPresentation({commandGraph});

viewer->compile();

There I can clearly see the openstreet map.

auto commandGraph = createCommandGraphForView(window, camera, sceneGraph);
auto renderGraph = vsg::RenderGraph::create(window);
commandGraph->addChild(renderGraph);

// Create the ImGui node and add it to the renderGraph
auto params = Params::create();
auto renderImGui = vsgImGui::RenderImGui::create(window, MyGui::create(params, options));
renderGraph->addChild(renderImGui);

viewer->assignRecordAndSubmitTaskAndPresentation({commandGraph});

viewer->compile();

Now I only see the Imgui window.

Can you help me, please?

Michel Guenin

[robertosfield]

From your code snippet I can't see a reason for a problem.

Does the vsgimgui_example from vsgExamples work OK for you?

vsgimgui_example models/openstreetmap.vsgt

This is what I see:

[Conan42]

Ah I don't understand then, apart from the fact that I installed the Ubuntu packages: libvulkan-dev vulkan-tools vulkan-utility-libraries-dev vulkan-validationlayers instead of Lunar's Vulkan SDK. I'll give you all the code:

#include <vsg/all.h>
#include <vsgXchange/all.h>
#include <vsgImGui/imgui.h>
#include <vsgImGui/Texture.h>
#include <vsgImGui/implot.h>
#include <vsgImGui/RenderImGui.h>
#include <vsgImGui/SendEventsToImGui.h>

#include <iostream>

struct Params final : public vsg::Inherit<vsg::Object, Params>
{
	bool showGui = true; // you can toggle this with your own EventHandler and key
	bool showDemoWindow = false;
	bool showSecondWindow = false;
	bool showImPlotDemoWindow = false;
	bool showLogoWindow = true;
	bool showImagesWindow = false;
	float clearColor[3]{0.2f, 0.2f, 0.4f}; // Unfortunately, this doesn't change dynamically in vsg
	uint32_t counter = 0;
	float dist = 0.f;
};

class MyGui final : public vsg::Inherit<vsg::Command, MyGui>
{
public:
    vsg::ref_ptr<vsgImGui::Texture> texture;
    vsg::ref_ptr<Params> params;

    explicit MyGui(const vsg::ref_ptr<Params>& in_params, const vsg::ref_ptr<vsg::Options>& options = {}) : params(in_params)
    {
        auto texData = vsg::read_cast<vsg::Data>("textures/VSGlogo.png", options);
        texture = vsgImGui::Texture::create_if(texData, texData);
    }

    // we need to compile textures before we can use them for rendering
    void compile(vsg::Context& context) override
    {
        if (texture) texture->compile(context);
    }

    // Example here taken from the Dear imgui comments (mostly)
    void record(vsg::CommandBuffer& cb) const override
    {
        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
        if (params->showGui)
        {
            ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it.

            ImGui::Text("Some useful message here.");                // Display some text (you can use format strings too)
            ImGui::Checkbox("Demo Window", &params->showDemoWindow); // Edit bools storing our window open/close state
            ImGui::Checkbox("Another Window", &params->showSecondWindow);
            ImGui::Checkbox("ImPlot Demo Window", &params->showImPlotDemoWindow);
            if (texture)
            {
                ImGui::Checkbox("Images Window", &params->showImagesWindow);
            }

            ImGui::SliderFloat("float", &params->dist, 0.0f, 1.0f);        // Edit 1 float using a slider from 0.0f to 1.0f
            ImGui::ColorEdit3("clear color", reinterpret_cast<float *>(&params->clearColor)); // Edit 3 floats representing a color. Beware: the color space will match the rendering color space, typically linear, whereas colour pickers are typically sRGB.

            if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated)
                params->counter++;

            ImGui::SameLine();
            ImGui::Text("counter = %d", params->counter);

            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
            ImGui::End();
        }

        // 3. Show another simple window.
        if (params->showSecondWindow)
        {
            ImGui::Begin("Another Window", &params->showSecondWindow); // Pass a pointer to our bool variable (the window will have a close button that will clear the bool when clicked)
            ImGui::Text("Hello from another window!");
            if (ImGui::Button("Close Me"))
                params->showSecondWindow = false;
            ImGui::End();
        }

        if (params->showDemoWindow)
        {
            ImGui::ShowDemoWindow(&params->showDemoWindow);
        }

        if (params->showImPlotDemoWindow)
        {
            ImPlot::ShowDemoWindow(&params->showImPlotDemoWindow);
        }
    }
};

int main() {
    /* Configurer l'objet options pour transmettre les chemins de fichier */
    const auto options = vsg::Options::create( vsgXchange::all::create() );
    options->paths = vsg::getDirectoryContents( "./" );	// Tous les autres répertoires sont dans le répertoire racine du programme
    options->fileCache = "./.cache";						// le répertoire "cache" est dans le répertoire racine du programme

	/* Spécification des paramètres de la future fenêtre vulkan */
    const auto windowTraits = vsg::WindowTraits::create();
    windowTraits->windowTitle = "vsgHelloWorld";
	windowTraits->width = 1280;
	windowTraits->height = 720;

	/* Création de la fenêtre Vulkan avec les paramètres windowTraits */
    const auto window = vsg::Window::create(windowTraits);
    if ( !window ) {
        std::cout << "Impossible de créer la fenêtre." << std::endl;
        return 1;
    }
	window->clearColor().set( 0.0f, 0.0f, 0.0f, 1.0f );		// Couleur de fond par défaut de la fenêtre

	/* Création de la visionneuse */
    auto viewer = vsg::Viewer::create();
    viewer->addWindow(window);												// Attribution de la fenêtre à la visionneuse

	// initialize ImGui
	ImGui::CreateContext();


	/* Création du Graphe de scène */
	const auto sceneGraph = vsg::read_cast<vsg::Node>( "data/models/openstreetmap_flat_shaded.vsgt", options );		// Chargement du Graphe de scène
	if ( !sceneGraph ) {
		std::cout << "Impossible de charger la scène." << std::endl;
		return 1;
	}

	// const auto sceneGraph = vsg::TileDatabase::create();
	// sceneGraph->settings = createOpenStreetMapSettings(options);
	// sceneGraph->readDatabase(options);

	/* Création d'un point de vue */
	auto const ellipsoid = sceneGraph->getRefObject<vsg::EllipsoidModel>("EllipsoidModel");				// Récupération dans la scène de l'objet dont l'id = EllipsoidModel
	auto const cartesienCoord = ellipsoid->convertLatLongAltitudeToECEF( { 45.39256, 3.9396, 100000.0 } );	// Conversion des coordonnées géographiques en coordonnées Cartésiennes x, y, z (en m)
	auto const pointDeVue = vsg::LookAt::create(	cartesienCoord + normalize( cartesienCoord ),
																cartesienCoord,
																normalize( cross( normalize( cartesienCoord ),cross( vsg::dvec3( 0.0, 0.0, 1.0 ), normalize( cartesienCoord ) ) ) )
															);

	/* Création d'une perspective */
    auto const perspective = vsg::EllipsoidPerspective::create( pointDeVue, ellipsoid, 30.0, static_cast<double>(window->extent2D().width) / static_cast<double>(window->extent2D().height), 0.001, 0.0 );

	/* Création de la caméra */
    auto const camera = vsg::Camera::create( perspective, pointDeVue, vsg::ViewportState::create( window->extent2D() ) );

    /* Ajoute un gestionnaire de fermeture pour répondre au bouton de fermeture de la fenêtre et appuyer sur échapper */
    viewer->addEventHandler( vsg::CloseHandler::create(viewer) );

	// Add the ImGui event handler first to handle events early
	viewer->addEventHandler(vsgImGui::SendEventsToImGui::create());

	/* Ajoute un gestionnaire d'événement de la souris */
	const auto trackball = vsg::Trackball::create(camera, ellipsoid);
	trackball->panButtonMask = vsg::BUTTON_MASK_1;
	trackball->rotateButtonMask = vsg::BUTTON_MASK_2;
	trackball->zoomButtonMask = vsg::BUTTON_MASK_4;

	viewer->addEventHandler(trackball);

	auto commandGraph = createCommandGraphForView(window, camera, sceneGraph);
	const auto renderGraph = vsg::RenderGraph::create(window);
	commandGraph->addChild(renderGraph);

	// Create the ImGui node and add it to the renderGraph
	auto params = Params::create();
	const auto renderImGui = vsgImGui::RenderImGui::create(window, MyGui::create(params, options));
	renderGraph->addChild(renderImGui);

	viewer->assignRecordAndSubmitTaskAndPresentation({commandGraph});

    viewer->compile();				// Compile tous les objets Vulkan et transfère les données d'image, de sommet et de primitive vers le GPU

	/* Rendu de la boucle principale */
    while (viewer->advanceToNextFrame()) {
        viewer->handleEvents();		// Réaction à tous les événements de la visionneuse
        viewer->update();			// Mettre à jour le graphique de la scène
        viewer->recordAndSubmit();	// Enregistrer et soumettre les commandes
        viewer->present();			// Attendre la fin du rendu et présentez le tampon
    }

    return 0;						// Nettoyage effectué automatiquement grâce au pointeur intelligent ref_ptr<>
}

There must be something I'm missing.

[robertosfield]

Before folks start looking at your code can you tell us what happens when you ruin:

 vsgimgui_example models/openstreetmap.vsgt

Does it look the same as my screenshot? Once we know this we have an idea whether it's your code or your drivers/hardware.

[Conan42]

my file ".bashrc":

export PATH="$PATH:/home/mich/vsgExamples/build/bin"
export VSG_FILE_PATH="/home/mich/vsgExamples/data"
export VSG_FILE_CACHE="/home/mich/var"

I made a mistake on VSG_FILE_PATH, I forgot the "s" of vsgExamples.

then I get:

and I put it back in the main:

    const auto options = vsg::Options::create( vsgXchange::all::create() );
options->fileCache = vsg::getEnv("VSG_FILE_CACHE");
options->paths = vsg::getEnvPaths("VSG_FILE_PATH");

and it's always the same:

either I see that Imgui:

    auto commandGraph = createCommandGraphForView(window, camera, sceneGraph);
const auto renderGraph = vsg::RenderGraph::create(window);
commandGraph->addChild(renderGraph);

// Create the ImGui node and add it to the renderGraph
auto params = Params::create();
const auto renderImGui = vsgImGui::RenderImGui::create(window, MyGui::create(params, options));
renderGraph->addChild(renderImGui);

viewer->assignRecordAndSubmitTaskAndPresentation({commandGraph});

either I see that the card:

    auto commandGraph = createCommandGraphForView(window, camera, sceneGraph);
//const auto renderGraph = vsg::RenderGraph::create(window);
//commandGraph->addChild(renderGraph);

// Create the ImGui node and add it to the renderGraph
//auto params = Params::create();
//const auto renderImGui = vsgImGui::RenderImGui::create(window, MyGui::create(params, options));
//renderGraph->addChild(renderImGui);

viewer->assignRecordAndSubmitTaskAndPresentation({commandGraph});

Merci Robert.

[robertosfield]

Just to be clear. When you run vsgimgui_example as is it runs and generates a screen image as you posted, and as the same as my screenshot, so vsgImGui/example is working. This does seem to confirm that it's not a driver/Vulkan/VSG issue but an issue with changes to the scene graph/viewer setup.

When you begin modifying the example you get problems, but I'm not clear on what bits you expecting to see in response to your modifications.

One thing you could try is to enable the Vulkan validation layer via WindowTraits and see if there are errors being generated in the different combinations of setup you are using.

[Conan42]

I put :

  windowTraits->debugLayer = true;

and when running, I don't see anything in the console.

[Conan42]

It's okay, I found:

// The commandGraph will contain a 2 stage renderGraph: 1) 3D scene 2) ImGui (by default also includes clearing of depth buffers)
auto commandGraph = vsg::CommandGraph::create(window);
const auto renderGraph = vsg::RenderGraph::create(window);
commandGraph->addChild(renderGraph);

// create the normal 3D view of the scene
const auto view = vsg::View::create(camera);
view->addChild(vsg::createHeadlight());
view->addChild(sceneGraph);

// Create the ImGui node and add it to the renderGraph
auto params = Params::create();
const auto renderImGui = vsgImGui::RenderImGui::create(window, MyGui::create(params, options));

renderGraph->addChild(view);
renderGraph->addChild(renderImGui);

viewer->assignRecordAndSubmitTaskAndPresentation({commandGraph});

And it works, thank you Robert