public Mat4[] CameraToCsmProjections(Camera camera, int count)
{
var camToLight = Mat.LookAt(-DirectionInCameraSpace(camera), new Vec3(0f, 1f, 0f));
return((from frustum in camera.SplitFrustumsForCascadedShadowMaps(count, 0.75f)
let corners = frustum.Corners.Map(p => camToLight.Transform(p))
let orthoBox = ViewingFrustum.FromBBox(Aabb <Vec3> .FromPositions(corners))
select orthoBox.CameraToScreen *camToLight)
.ToArray());
}
/// <summary>
/// Set the texture coordinates for all the vertices facing towards the viewer when
/// vertices are transformed according to a given projection matrix.
/// </summary>
/// <description>>
/// When applying textures to complex geometries it can be tricky to set the texture coordinates
/// for faces. The idea of texture projection is used to make this process easier. A texture is
/// applied to the geometry that is viewed from a specified angle and using typically an
/// orthographic projection. This way it is easier to select the faces you want to apply the
/// texture. It is also possible to devise more complex ways of setting the texture coordinates
/// by doing the projection multiple times from different angles. By that you can build for example
/// a cylindrical or spherical projection and apply a panoramic texture, i.e. a texture that exceeds
/// the given field of view.
/// </description>
/// <param name="geometry">Geometry to which the texture coordinates are applied.</param>
/// <param name="projection">The projection matrix used to orient and project the geometry for
/// applying the texture coordinates.</param>
/// <param name="minCosAngle">The cosine of the minimum angle between the inverse viewing vector
/// ([0, 0, 1] in the projected coordinate system) and the normal of the vertex for which the
/// texture positions are set. This parameter can be used to fine tune which faces are filtered
/// out from the process.</param>
/// <param name="minPos">The minimum texture position that is set. I.e. the lower left corner
/// of the applied texture viewport.</param>
/// <param name="maxPos">The maximum texture position that is set. Corresponds to the top right corner
/// of the applied texture viewport.</param>
/// <typeparam name="V">The vertex type. Must implement the IVertex and ITextured interfaces.</typeparam>
public static void ApplyTextureCoordinates<V> (this Geometry<V> geometry, Mat4 projection, float minCosAngle,
Vec2 minPos, Vec2 maxPos) where V : struct, IVertex3D, ITextured
{
var projected = geometry.Transform (projection);
var range = maxPos - minPos;
var invView = new Vec3 (0f, 0f, 1f);
var bbox = Aabb<Vec3>.FromPositions (projected.Vertices.Where (
v => v.normal.Dot (invView) >= minCosAngle).Select (v => v.position));
var scaleX = range.X / bbox.Size.X;
var scaleY = range.Y / bbox.Size.Y;
for (int i = 0; i < geometry.Vertices.Length; i++)
{
var pv = projected.Vertices[i];
if (pv.normal.Dot (invView) >= minCosAngle)
geometry.Vertices[i].texturePos = new Vec2 (
(pv.position.X - bbox.Left) * scaleX + minPos.X,
(pv.position.Y - bbox.Bottom) * scaleY + minPos.Y);
}
}