class mrpt::imgui::CImGuiSceneView

Overview

Renders an mrpt::viz::Scene into an OpenGL FBO texture and displays it as a Dear ImGui image widget, with built-in orbit camera controls.

Usage:

// In your ImGui frame loop:
if (ImGui::Begin("3D View"))
{
    sceneView.render();
}
ImGui::End();

The class assumes an OpenGL 3.3+ context is already current (as provided by the Dear ImGui GLFW/SDL backend). No EGL context is created.

#include <mrpt/imgui/CImGuiSceneView.h>

class CImGuiSceneView
{
public:
    // fields

    mrpt::viz::COrbitCameraController cameraController;
    std::function<void()> onOverlayGui;
    std::function<void(float, float)> onLeftClick;

    // construction

    CImGuiSceneView();
    CImGuiSceneView(const CImGuiSceneView&);
    CImGuiSceneView(CImGuiSceneView&&);

    // methods

    void setScene(const mrpt::viz::Scene::Ptr& scene);
    mrpt::viz::Scene::Ptr scene() const;
    void render();
    void setBackgroundColor(float r, float g, float b, float a = 1.0f);
    CImGuiSceneView& operator = (const CImGuiSceneView&);
    CImGuiSceneView& operator = (CImGuiSceneView&&);
};

Fields

mrpt::viz::COrbitCameraController cameraController

The orbit camera controller.

Use this to read/write azimuth, elevation, zoom distance, pointing-at position, and interaction sensitivities.

Example:

view.cameraController.setZoomDistance(20.0f);
view.cameraController.setAzimuthDegrees(-135.0f);
view.cameraController.orbitSensitivity = 0.5f;

std::function<void()> onOverlayGui

Called after the MRPT scene is rendered but before ImGui::Image().

Useful for drawing overlay ImGui widgets on top.

std::function<void(float, float)> onLeftClick

Called when the user left-clicks on the 3D view without dragging.

Arguments: (pixel_x, pixel_y) in widget-local coordinates.

Methods

void setScene(const mrpt::viz::Scene::Ptr& scene)

Set the scene to render.

The caller retains ownership.

mrpt::viz::Scene::Ptr scene() const

Get the scene being rendered (may be nullptr).

void render()

Renders the scene into the FBO and displays it via ImGui::Image().

Call this inside an ImGui window (between Begin/End).

The widget fills the available content region. If the region size changed since the last call, the FBO is recreated automatically.

void setBackgroundColor(float r, float g, float b, float a = 1.0f)

Background color override.

If never called, the scene’s own viewport background (typically a vertical gradient set up by mrpt::viz::Scene) is preserved.