BloodyMess Ogre::Terrain Heightfield

This page is related to a deprecated version of NxOgre, called BloodyMess. Some code from here may be adopted to newer versions with sufficient care and knowledge.

Help: For any problems you encounter while working with these code, please visit the thread in the NxOgre forum.

BloodyMess Ogre::Terrain heightfield

This code shows how to create a matching heightfield from the new Ogre::Terrain, a new feature in Ogre 1.7.

It does everything in realtime, so there is no need to use flour to create an .xhf or flip and rotate the heightmap.

Thanks to XpLoDWilD for solving an issue with vertex under the origin.

void loadTerrainGeometry(const Ogre::String& name, float* data, Ogre::uint16 size, Ogre::Real worldSize, Ogre::Real minHeight, Ogre::Real maxHeight, const Ogre::Vector3& position)
{
	// Create the manual heightfield
	NxOgre::ManualHeightField *mhf = OGRE_NEW_T(NxOgre::ManualHeightField, Ogre::MEMCATEGORY_GENERAL)();
	mhf->begin(size, size);
	Ogre::Real normMin = -32768.0f;
	Ogre::Real normMax = 32767.0f;
	// Sample the data to the manual heightfield
	for(int x = 0; x < size; ++x)
	{
		NxOgre::Enums::HeightFieldTesselation tess = NxOgre::Enums::HeightFieldTesselation_NW_SE;
		for(int z = size-1; z >= 0; --z)
		{
			Ogre::Real height = data[(size * z) + x];
			short sample = (short)(((height - minHeight) / (maxHeight - minHeight)) * (normMax - normMin) + normMin);
			mhf->sample(sample, 0, 0, tess);
			if(tess == NxOgre::Enums::HeightFieldTesselation_NE_SW)
				tess = NxOgre::Enums::HeightFieldTesselation_NW_SE;
			else
				tess = NxOgre::Enums::HeightFieldTesselation_NE_SW;
		}
	}
	// Create the actual heightfield
	NxOgre::HeightField *hf = mhf->end(name.c_str());
	Ogre::Real hf_size = worldSize + (worldSize / size);
	Ogre::Real hf_height = (maxHeight - minHeight) / 2.0f;
	Ogre::Real hf_pose_x = position.x - (worldSize / 2.0f);
	Ogre::Real hf_pose_y = position.y + ((maxHeight + minHeight) / 2.0f);
	Ogre::Real hf_pose_z = position.z - (worldSize / 2.0f);
#if NxOgreVersionMajor <= 1 && NxOgreVersionMinor <= 5
	NxOgre::HeightFieldGeometry* hfg = new NxOgre::HeightFieldGeometry(hf, NxOgre::Vec3(hf_size, hf_height, hf_size));
	hfg->setLocalPose(NxOgre::Matrix44(NxOgre::Vec3(hf_pose_x, hf_pose_y, hf_pose_z)));
	mScene->createSceneGeometry(hfg);
#else
	NxOgre::HeightFieldGeometryDescription desc(hf, NxOgre::Vec3(hf_size, hf_height, hf_size));
	mScene->createSceneGeometry(desc, NxOgre::Matrix44(NxOgre::Vec3(hf_pose_x, hf_pose_y, hf_pose_z)));
#endif
	// Free memory
	OGRE_DELETE_T(mhf, ManualHeightField, Ogre::MEMCATEGORY_GENERAL);
}

You can use it like that, with "terrain" being a pointer to your Ogre::Terrain.

loadTerrainGeometry(terrain->getMaterialName(), terrain->getHeightData(), terrain->getSize(),
	terrain->getWorldSize(), terrain->getMinHeight(), terrain->getMaxHeight(), terrain->getPosition());

Or you can supply the data yourself.