History: Displaying 2D Backgrounds
Preview of version: 13
A frequently asked question is how to display a 2D background image in OGRE. Here is an example of how to achieve this using the Rectangle2D class. This also demonstrates e.g. how to easily scroll the background.
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// Create background material MaterialPtr material = MaterialManager::getSingleton().create("Background", "General"); material->getTechnique(0)->getPass(0)->createTextureUnitState("rockwall.tga"); material->getTechnique(0)->getPass(0)->setDepthCheckEnabled(false); material->getTechnique(0)->getPass(0)->setDepthWriteEnabled(false); material->getTechnique(0)->getPass(0)->setLightingEnabled(false); // Create background rectangle covering the whole screen Rectangle2D* rect = new Rectangle2D(true); rect->setCorners(-1.0, 1.0, 1.0, -1.0); rect->setMaterial("Background"); // Render the background before everything else rect->setRenderQueueGroup(RENDER_QUEUE_BACKGROUND); // Use infinite AAB to always stay visible AxisAlignedBox aabInf; aabInf.setInfinite(); rect->setBoundingBox(aabInf); // Attach background to the scene SceneNode* node = mSceneMgr->getRootSceneNode()->createChildSceneNode("Background"); node->attachObject(rect); // Example of background scrolling material->getTechnique(0)->getPass(0)->getTextureUnitState(0)->setScrollAnimation(-0.25, 0.0); // Don't forget to delete the Rectangle2D in the destructor of your application: delete rect;
Note: You cannot add the 2D Rectangle directly to the root scene node. It will not show up.
Here is the port to MOGRE:
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// Create background material MaterialPtr material = MaterialManager.Singleton.Create("Background", "General"); material.GetTechnique(0).GetPass(0).CreateTextureUnitState("rockwall.tga"); material.GetTechnique(0).GetPass(0).DepthCheckEnabled = false; material.GetTechnique(0).GetPass(0).DepthWriteEnabled = false; material.GetTechnique(0).GetPass(0).LightingEnabled = false; // Create background rectangle covering the whole screen Rectangle2D rect = new Rectangle2D(true); rect.SetCorners(-1.0f, 1.0f, 1.0f, -1.0f); rect.SetMaterial("Background"); // Render the background before everything else rect.RenderQueueGroup = (byte)RenderQueueGroupID.RENDER_QUEUE_BACKGROUND; // Use infinite AAB to always stay visible AxisAlignedBox aab = new AxisAlignedBox(); aab.SetInfinite(); rect.BoundingBox = aab; // Attach background to the scene SceneNode node = mSmgr.RootSceneNode.CreateChildSceneNode("Background"); node.AttachObject(rect); // Example of background scrolling material.GetTechnique(0).GetPass(0).GetTextureUnitState(0).SetScrollAnimation(-0.25f, 0.0f);
See also
- Rectangle in Ogre API
- {LEX()}Overlay{LEX}
- {LEX()}Material{LEX}
- {LEX()}AABB{LEX}
Alias: Displaying_2D_Backgrounds