Strange lighting issue

[Abstergo]

Hey gang, I'm running into an issue with lighting an object.

I have a Model I'm using to produce a floor, which currently just places 10 by 10 1x1 Surfaces in a flat grid. I also have a light hanging overhead, a Spotlight angled straight down in the center.

As you can see the light cuts off right down the centerline Z axis of the object, leaving a semicircle illuminated. I initially thought this was tied to specific coordinates, however I get the problem wherever I place the object & light. I've tried a Pointlight, with the same results.

The floor is generated in the Attach method of the Model's actor class. Note it creates and attaches a child Model, because this way it can easily be removed and changed on the fly.

	Model* m_terrain;
	m_terrain = (Model*)this->entity->FindChild("terrain_model");
	if (m_terrain != nullptr) m_terrain->Release();

	Texture* t = Texture::Load("Materials/Terrain/terrain_theZone_x2plainmud.tex");
	t->SetClampMode(true, true);
	Shader* s = Shader::Load("Shaders/Model/diffuse.shader");
	Material* m = Material::Create();
	m->SetShader(s);
	m->SetTexture(t);
	m->SetBlendMode(Blend::Solid);
	m->SetShadowMode(true);

	m_terrain = Model::Create(this->entity);
	m_terrain->SetKeyValue("name", "terrain_model");
	float x, z;
	for (x = 0.0; x < 10.0; x++) {
		for (z = 0.0; z < 10.0; z++) {
			Surface* sur_face = m_terrain->AddSurface();
			sur_face->AddVertex(x, 0.0, z, 0, 0, -1);
			sur_face->AddVertex(x + 1.0, 0.0, z, 0, 0, -1);
			sur_face->AddVertex(x + 1.0, 0.0, z + 1.0, 0, 0, -1);
			sur_face->AddVertex(x, 0.0, z + 1.0, 0, 0, -1);
			sur_face->SetVertexTexCoords(0, 0, 0, 0);
			sur_face->SetVertexTexCoords(1, 1, 0, 0);
			sur_face->SetVertexTexCoords(2, 1, 1, 0);
			sur_face->SetVertexTexCoords(3, 0, 1, 0);
			sur_face->AddTriangle(2, 1, 0);
			sur_face->AddTriangle(0, 3, 2);
			sur_face->SetMaterial(m);
			sur_face->Update();
		}
	}
	m_terrain->SetPosition(Vec3(0.0),false);
	m_terrain->SetShadowMode(Light::Static);
	m_terrain->UpdateAABB(Entity::LocalAABB | Entity::GlobalAABB);

Anybody got ideas for what I'm doing wrong?

[Josh]

You are using (0,0,-1) for your normals. Try using (0,1,0).

[Abstergo]

Thanks Josh, that did the trick.