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author | KT <tran0563@umn.edu> | 2021-09-06 19:07:33 -0500 |
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committer | KT <tran0563@umn.edu> | 2021-09-06 19:07:33 -0500 |
commit | cccd3186305915d92b1751dc616979d64116a4aa (patch) | |
tree | 5dd4834daef547cd45fc0b643f44a10b581de0ad /dev/a6-harold/billboards.cc | |
parent | Added missing images for the A6 worksheet (diff) | |
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diff --git a/dev/a6-harold/billboards.cc b/dev/a6-harold/billboards.cc deleted file mode 100644 index 5ec508a..0000000 --- a/dev/a6-harold/billboards.cc +++ /dev/null @@ -1,206 +0,0 @@ -/** CSci-4611 Assignment 6: Harold - */ - -#include "billboards.h" - -Billboards::Billboards() { - -} - - -Billboards::~Billboards() { - -} - - -void Billboards::Init(ShaderProgram *stroke3d_shaderprog) { - stroke3d_shaderprog_ = stroke3d_shaderprog; -} - - -/// Projects a 2D normalized screen point (e.g., the mouse position in normalized -/// device coordinates) to a 3D point on a plane defined by an "origin", which can -/// really be any point coincident with the plane, and the plane normal. Returns -/// true if the screen point projects onto the plane and stores the result in -/// plane_point. Returns false if the screen point does not project onto the plane. -bool Billboards::ScreenPtHitsPlane(const Matrix4 &view_matrix, const Matrix4 &proj_matrix, - const Point3 &plane_origin, const Vector3 &plane_normal, - const Point2 &normalized_screen_pt, Point3 *plane_point) -{ - Matrix4 camera_matrix = view_matrix.Inverse(); - Point3 eye = camera_matrix.ColumnToPoint3(3); - - Point3 pt3d = GfxMath::ScreenToNearPlane(view_matrix, proj_matrix, normalized_screen_pt); - Ray ray(eye, (pt3d - eye).ToUnit()); - float t; - return ray.IntersectPlane(plane_origin, plane_normal, &t, plane_point); -} - - -/// Checks to see if a ray starting at the eye point and passing through 2D -/// normalized screen point projects onto any of the billboards in the scene. If -/// so, returns the id of the closest billboard intersected. If not, returns -1. -int Billboards::IntersectBillboard(const Matrix4 &view_matrix, const Matrix4 &proj_matrix, - const Point2 &normalized_screen_pt) -{ - Matrix4 camera_matrix = view_matrix.Inverse(); - Point3 eye = camera_matrix.ColumnToPoint3(3); - - int id = -1; - float best_i_time = -1.0; - - Point3 pt3d = GfxMath::ScreenToNearPlane(view_matrix, proj_matrix, normalized_screen_pt); - Ray ray(eye, (pt3d - eye).ToUnit()); - - Point3 i_point; - float i_time; - int i_tri_id; - for (int i=0; i<billboards_.size(); i++) { - Matrix4 to_billboard_space = billboards_[i].transform.Inverse(); - Ray ray_billboard_space = to_billboard_space * ray; - if ((ray_billboard_space.IntersectAABB(billboards_[i].bounding_box, &i_time)) && - (ray_billboard_space.IntersectMesh(billboards_[i].mesh, &i_time, &i_point, &i_tri_id)) && - ((best_i_time == -1.0) || (i_time < best_i_time))) { - id = i; - } - } - - return id; -} - - -/// Adds a new stroke as a billboard by projecting it onto a plane parallel -/// to the filmplane that intersects with the base point, which should lie -/// on the ground. -void Billboards::AddBillboardStroke(const Matrix4 &view_matrix, const Matrix4 &proj_matrix, - const std::vector<Point2> &stroke2d, const Mesh &stroke2d_mesh, - const Color &stroke_color, Ground *ground_ptr) -{ - Matrix4 camera_matrix = view_matrix.Inverse(); - Point3 eye = camera_matrix.ColumnToPoint3(3); - - // Create a new billboard - Billboard b; - b.color = stroke_color; - b.transform = Matrix4(); - b.mesh = stroke2d_mesh; - - // find the base point for the billboard - ground_ptr->ScreenPtHitsGround(view_matrix, proj_matrix, stroke2d[0], &b.anchor_pt); - Vector3 norm = (eye - b.anchor_pt); - norm[1] = 0.0; // with 0 change in Y so the billboard does not tilt - norm.Normalize(); // convert to a unit vector - - // project the stroke into 3D to lie on the projection plane - std::vector<Point3> verts; - for (int i=0; i<b.mesh.num_vertices(); i++) { - Point2 pscreen = Point2(b.mesh.read_vertex_data(i)[0], b.mesh.read_vertex_data(i)[1]); - Point3 pplane; - ScreenPtHitsPlane(view_matrix, proj_matrix, b.anchor_pt, norm, pscreen, &pplane); - verts.push_back(pplane); - } - - Matrix4 to_canonical_billboard = Matrix4::Align(b.anchor_pt, Vector3::UnitY(), norm, - Point3::Origin(), Vector3::UnitY(), Vector3::UnitZ()); - - for (int i=0; i<verts.size(); i++) { - verts[i] = to_canonical_billboard * verts[i]; - } - - b.mesh.SetVertices(verts); - - for (int i=0; i<b.mesh.num_vertices(); i++) { - b.bounding_box = b.bounding_box + AABB(b.mesh.read_vertex_data(i)); - } - b.bounding_box.set_user_data((int)billboards_.size()); - - billboards_.push_back(b); -} - - -/// Edits an existing billboard by adding an additional stroke to it. -void Billboards::AddToBillboard(const Matrix4 &view_matrix, const Matrix4 &proj_matrix, - int billboard_id, const Mesh &stroke2d_mesh, - const Color &stroke_color) -{ - Matrix4 camera_matrix = view_matrix.Inverse(); - Point3 eye = camera_matrix.ColumnToPoint3(3); - - // Really what this does is add a new billboard that lies in the same plane - // as the one we are "editing" and has the same anchor point so that they - // will both rotate the same way. - Billboard b; - b.color = stroke_color; - b.transform = Matrix4(); - b.mesh = stroke2d_mesh; - - b.anchor_pt = billboards_[billboard_id].anchor_pt; - - - Vector3 norm = (eye - b.anchor_pt); - norm[1] = 0.0; // with 0 change in Y so the billboard does not tilt - norm.Normalize(); // convert to a unit vector - - // project the stroke into 3D to lie on the projection plane - std::vector<Point3> verts; - for (int i=0; i<b.mesh.num_vertices(); i++) { - Point2 pscreen = Point2(b.mesh.read_vertex_data(i)[0], b.mesh.read_vertex_data(i)[1]); - Point3 pplane; - ScreenPtHitsPlane(view_matrix, proj_matrix, b.anchor_pt, norm, pscreen, &pplane); - verts.push_back(pplane); - } - - Matrix4 to_canonical_billboard = Matrix4::Align(b.anchor_pt, Vector3::UnitY(), norm, - Point3::Origin(), Vector3::UnitY(), Vector3::UnitZ()); - - for (int i=0; i<verts.size(); i++) { - verts[i] = to_canonical_billboard * verts[i]; - } - - b.mesh.SetVertices(verts); - - for (int i=0; i<b.mesh.num_vertices(); i++) { - b.bounding_box = b.bounding_box + AABB(b.mesh.read_vertex_data(i)); - } - b.bounding_box.set_user_data((int)billboards_.size()); - - billboards_.push_back(b); -} - - -void Billboards::UpdateBillboardRotations(const Point3 ¤t_eye_point) { - // Whenver the camera moves, we also need to rotate the billboards so - // that they always face the viewer. - for (int i=0; i<billboards_.size(); i++) { - // billboards are stored in a coordinate system where the base is - // at (0,0,0), rotation happens about the Y axis, and the billboard's - // normal is +Z. - Point3 a_p = Point3(0,0,0); // 'anchor point' in billboard coordinates - Vector3 a_v1 = Vector3::UnitY(); // 'up' in billboard coordinates - Vector3 a_v2 = Vector3::UnitZ(); // 'normal' in billboard coordinates - - Point3 b_p = billboards_[i].anchor_pt; // 'anchor point' in world coordinates - Vector3 b_v1 = Vector3::UnitY(); // 'up' in world coordinates - Vector3 b_v2 = (current_eye_point - b_p); // 'normal' in world coordinates - b_v2[1] = 0.0; // force 0 change in Y so the billboard does not tilt - b_v2.Normalize(); // convert to a unit vector - - billboards_[i].transform = Matrix4::Align(a_p,a_v1,a_v2, b_p,b_v1,b_v2); - } -} - - -void Billboards::Draw(const Matrix4 &view_matrix, const Matrix4 &proj_matrix) { - // Draw billboard meshes - stroke3d_shaderprog_->UseProgram(); - stroke3d_shaderprog_->SetUniform("projectionMatrix", proj_matrix); - for (int i=0; i<billboards_.size(); i++) { - Matrix4 model_matrix = billboards_[i].transform; - Matrix4 modelview_matrix = view_matrix * model_matrix; - stroke3d_shaderprog_->SetUniform("modelViewMatrix", modelview_matrix); - stroke3d_shaderprog_->SetUniform("strokeColor", billboards_[i].color); - billboards_[i].mesh.Draw(); - } - stroke3d_shaderprog_->StopProgram(); -} - |