Ok,

et voici :

irr::scene::ITerrainSceneNode* terrain = smgr->addTerrainSceneNode(
                "./media/Map1_field.bmp",
                0,                                      // parent node
                -1,                                     // node id
                irr::core::vector3df(-900.f, -50.f, -900.f),         // position
                irr::core::vector3df(0.f, 0.f, 0.f),         // rotation
                irr::core::vector3df(2.f, 1.0f, 2.f),      // scale
                irr::video::SColor ( 255, 255, 255, 255 ),   // vertexColor
                5,                                      // maxLOD
                irr::scene::ETPS_17,                         // patchSize
                4                                       // smoothFactor
                );
        irr::core::vector3df center = terrain->getTerrainCenter();
        terrain->setMaterialFlag(video::EMF_LIGHTING, false);

        terrain->setMaterialTexture(0,
                                    driver->getTexture("./media/Maps/Ground_Global.jpg"));
                        //driver->getTexture("./media/terrain-texture.jpg"));
        terrain->setMaterialTexture(1,
                        driver->getTexture("./media/Maps/Grass_Global.jpg"));
                        //driver->getTexture("./media/detailmap3.jpg"));

        terrain->setMaterialType(video::EMT_DETAIL_MAP);

        terrain->scaleTexture(150.0f, 400.0f);
        // create triangle selector for the terrain
        scene::ITriangleSelector* selector = smgr->createTerrainTriangleSelector(terrain, 0);
        terrain->setTriangleSelector(selector);

Merci de ta réponse rapide !