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RM_tube

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This commit is contained in:
David Rose 2005-01-07 23:57:35 +00:00
parent 4d1615b740
commit bacd4ad811
3 changed files with 602 additions and 206 deletions
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114
panda/src/parametrics/ropeNode.I
View File

@ -29,8 +29,11 @@ CData() {
_uv_mode = RopeNode::UV_none;
_u_dominant = true;
_uv_scale = 1.0f;
_normal_mode = RopeNode::NM_none;
_tube_up = LVector3f::up();
_use_vertex_color = false;
_num_subdiv = 10;
_num_slices = 5;
_thickness = 1.0f;
}
@ -46,8 +49,11 @@ CData(const RopeNode::CData &copy) :
_uv_mode(copy._uv_mode),
_u_dominant(copy._u_dominant),
_uv_scale(copy._uv_scale),
_normal_mode(copy._normal_mode),
_tube_up(copy._tube_up),
_use_vertex_color(copy._use_vertex_color),
_num_subdiv(copy._num_subdiv),
_num_slices(copy._num_slices),
_thickness(copy._thickness)
{
}
@ -149,23 +155,6 @@ get_uv_direction() const {
return cdata->_u_dominant;
}
////////////////////////////////////////////////////////////////////
// Function: set_uv_scale
// Access: Published
// Description: Specifies an additional scaling factor to apply to
// generated UV's for the rope. This is a deprecated
// interface; use set_uv_scale() that accepts a single
// float, instead.
////////////////////////////////////////////////////////////////////
INLINE void RopeNode::
set_uv_scale(const LVecBase2f &uv_scale) {
if (get_uv_direction()) {
set_uv_scale(uv_scale[0]);
} else {
set_uv_scale(uv_scale[1]);
}
}
////////////////////////////////////////////////////////////////////
// Function: set_uv_scale
// Access: Published
@ -192,6 +181,64 @@ get_uv_scale() const {
return cdata->_uv_scale;
}
////////////////////////////////////////////////////////////////////
// Function: set_normal_mode
// Access: Published
// Description: Specifies the kind of normals to generate for the
// rope. This is only applicable when the RenderMode is
// set to RM_tube; in the other render modes, normals
// are never generated.
////////////////////////////////////////////////////////////////////
INLINE void RopeNode::
set_normal_mode(RopeNode::NormalMode normal_mode) {
CDWriter cdata(_cycler);
cdata->_normal_mode = normal_mode;
}
////////////////////////////////////////////////////////////////////
// Function: get_normal_mode
// Access: Published
// Description: Returns the kind of normals to generate for the rope.
// This is only applicable when the RenderMode is set to
// RM_tube.
////////////////////////////////////////////////////////////////////
INLINE RopeNode::NormalMode RopeNode::
get_normal_mode() const {
CDReader cdata(_cycler);
return cdata->_normal_mode;
}
////////////////////////////////////////////////////////////////////
// Function: set_tube_up
// Access: Published
// Description: Specifies a normal vector, generally perpendicular to
// the main axis of the starting point of the curve,
// that controls the "top" of the curve, when RenderMode
// is RM_tube. This is used to orient the vertices that
// make up the tube. If this vector is too nearly
// parallel with the starting direction of the curve,
// there may be a tendency for the whole tube to
// gimble-lock around its primary axis.
////////////////////////////////////////////////////////////////////
INLINE void RopeNode::
set_tube_up(const LVector3f &tube_up) {
CDWriter cdata(_cycler);
cdata->_tube_up = tube_up;
}
////////////////////////////////////////////////////////////////////
// Function: get_tube_up
// Access: Published
// Description: Returns the normal vector used to control the "top"
// of the curve, when RenderMode is RM_tube. See
// set_tube_up().
////////////////////////////////////////////////////////////////////
INLINE const LVector3f &RopeNode::
get_tube_up() const {
CDReader cdata(_cycler);
return cdata->_tube_up;
}
////////////////////////////////////////////////////////////////////
// Function: set_use_vertex_color
// Access: Published
@ -246,6 +293,39 @@ get_num_subdiv() const {
return cdata->_num_subdiv;
}
////////////////////////////////////////////////////////////////////
// Function: set_num_slices
// Access: Published
// Description: Specifies the number of radial subdivisions to make
// if RenderMode is RM_tube. It is ignored in the other
// render modes.
//
// Increasing this number increases the roundness of a
// cross-section of the tube. The minimum value for a
// dimensional tube is 3; setting it to 2 will get you a
// thin piece of tape (which is similar to RM_billboard,
// except it won't rotate to face the camera).
////////////////////////////////////////////////////////////////////
INLINE void RopeNode::
set_num_slices(int num_slices) {
nassertv(num_slices >= 0);
CDWriter cdata(_cycler);
cdata->_num_slices = num_slices;
}
////////////////////////////////////////////////////////////////////
// Function: get_num_slices
// Access: Published
// Description: Returns the number of radial subdivisions to make if
// RenderMode is RM_tube. It is ignored in the other
// render modes. See set_num_slices().
////////////////////////////////////////////////////////////////////
INLINE int RopeNode::
get_num_slices() const {
CDReader cdata(_cycler);
return cdata->_num_slices;
}
////////////////////////////////////////////////////////////////////
// Function: set_thickness
// Access: Published

629
panda/src/parametrics/ropeNode.cxx
View File

@ -165,6 +165,10 @@ cull_callback(CullTraverser *trav, CullTraverserData &data) {
case RM_billboard:
render_billboard(trav, data, result);
break;
case RM_tube:
render_tube(trav, data, result);
break;
}
}
}
@ -265,89 +269,45 @@ do_recompute_bound(const NodePath &rel_to) {
////////////////////////////////////////////////////////////////////
void RopeNode::
render_thread(CullTraverser *trav, CullTraverserData &data,
NurbsCurveResult *result) {
UVMode uv_mode = get_uv_mode();
float uv_scale = get_uv_scale();
bool u_dominant = get_uv_direction();
bool use_vertex_color = get_use_vertex_color();
NurbsCurveResult *result) const {
CurveSegments curve_segments;
get_connected_segments(curve_segments, result);
// Now we have stored one or more sequences of vertices down the
// center strips. Go back through and calculate the vertices on
// either side.
PTA_Vertexf verts;
PTA_TexCoordf uvs;
PTA_Colorf colors;
compute_thread_vertices(verts, uvs, colors, curve_segments);
// Finally, build the lengths array to make them into proper
// line strips.
PTA_int lengths;
int num_prims = 0;
int num_verts = get_num_subdiv() + 1;
int num_segments = result->get_num_segments();
float dist = 0.0f;
for (int segment = 0; segment < num_segments; segment++) {
LPoint3f last_point;
for (int i = 0; i < num_verts; i++) {
float t = (float)i / (float)(num_verts - 1);
LPoint3f point;
result->eval_segment_point(segment, t, point);
verts.push_back(point);
CurveSegments::const_iterator si;
for (si = curve_segments.begin(); si != curve_segments.end(); ++si) {
const CurveSegment &segment = (*si);
if (use_vertex_color) {
Colorf color;
result->eval_segment_extended_points(segment, t, 0, &color[0], 4),
colors.push_back(color);
}
t = result->get_segment_t(segment, t);
switch (uv_mode) {
case UV_none:
break;
case UV_parametric:
if (u_dominant) {
uvs.push_back(TexCoordf(t * uv_scale, 0.0f));
} else {
uvs.push_back(TexCoordf(0.0f, t * uv_scale));
}
break;
case UV_distance:
if (i != 0) {
LVector3f vec = point - last_point;
dist += vec.length();
}
if (u_dominant) {
uvs.push_back(TexCoordf(dist * uv_scale, 0.0f));
} else {
uvs.push_back(TexCoordf(0.0f, dist * uv_scale));
}
break;
case UV_distance2:
if (i != 0) {
LVector3f vec = point - last_point;
dist += vec.length_squared();
}
if (u_dominant) {
uvs.push_back(TexCoordf(dist * uv_scale, 0.0f));
} else {
uvs.push_back(TexCoordf(0.0f, dist * uv_scale));
}
break;
}
last_point = point;
}
lengths.push_back(num_verts);
lengths.push_back(segment.size());
num_prims++;
}
PT(GeomLinestrip) geom = new GeomLinestrip;
geom->set_width(get_thickness());
geom->set_num_prims(num_segments);
geom->set_num_prims(num_prims);
geom->set_coords(verts);
if (uv_mode != UV_none) {
if (get_uv_mode() != UV_none) {
geom->set_texcoords(uvs, G_PER_VERTEX);
}
if (use_vertex_color) {
if (get_use_vertex_color()) {
geom->set_colors(colors, G_PER_VERTEX);
} else {
colors.push_back(Colorf(1.0f, 1.0f, 1.0f, 1.0f));
geom->set_colors(colors, G_OVERALL);
}
geom->set_lengths(lengths);
@ -365,11 +325,11 @@ render_thread(CullTraverser *trav, CullTraverserData &data,
// perpendicular to the camera plane.
//
// In this mode, thickness is in spatial units, and
// determines the with of the triangle strips.
// determines the width of the triangle strips.
////////////////////////////////////////////////////////////////////
void RopeNode::
render_billboard(CullTraverser *trav, CullTraverserData &data,
NurbsCurveResult *result) {
NurbsCurveResult *result) const {
const TransformState *net_transform = data._net_transform;
const TransformState *camera_transform = trav->get_camera_transform();
@ -377,142 +337,48 @@ render_billboard(CullTraverser *trav, CullTraverserData &data,
net_transform->invert_compose(camera_transform);
LVector3f camera_vec = LVector3f::forward() * rel_transform->get_mat();
float thickness = get_thickness();
float radius = thickness * 0.5f;
UVMode uv_mode = get_uv_mode();
bool u_dominant = get_uv_direction();
float uv_scale = get_uv_scale();
// We can't just build one tristrip per segment. Instead, we should
// build one continuous tristrip for all connected segments, so we
// can stitch them together properly at the seams.
int num_verts = get_num_subdiv() + 1;
int num_segments = result->get_num_segments();
vector_Vertexf center_verts;
vector_int center_lengths;
vector_float center_t;
LPoint3f point;
int cur_length = 0;
for (int segment = 0; segment < num_segments; segment++) {
LPoint3f first_point;
result->eval_segment_point(segment, 0.0f, first_point);
if (cur_length == 0 || point != first_point) {
// If the first point of this segment is different from the last
// point of the previous segment, end the tristrip and store the
// point.
if (cur_length != 0) {
center_lengths.push_back(cur_length);
}
center_verts.push_back(first_point);
center_t.push_back(result->get_segment_t(segment, 0.0f));
cur_length = 1;
}
// Store all the remaining points in this segment.
for (int i = 1; i < num_verts; i++) {
float t = (float)i / (float)(num_verts - 1);
result->eval_segment_point(segment, t, point);
center_verts.push_back(point);
center_t.push_back(result->get_segment_t(segment, t));
cur_length++;
}
}
if (cur_length != 0) {
center_lengths.push_back(cur_length);
}
CurveSegments curve_segments;
get_connected_segments(curve_segments, result);
// Now we have stored one or more sequences of vertices down the
// center strips. Go back and convert them into actual tristrips.
// center strips. Go back through and calculate the vertices on
// either side.
PTA_Vertexf verts;
PTA_TexCoordf uvs;
PTA_Colorf colors;
compute_billboard_vertices(verts, uvs, colors, camera_vec,
curve_segments, result);
// Finally, build the lengths array to make them into proper
// triangle strips. We don't need a vindex array here, since the
// vertices just happened to end up in tristrip order.
PTA_int lengths;
int vi = 0;
int num_prims = 0;
float dist = 0.0f;
for (int i = 0; i < (int)center_lengths.size(); i++) {
int length = center_lengths[i];
for (int j = 0; j < length; j++) {
const Vertexf &point = center_verts[vi + j];
float t = center_t[vi + j];
LVector3f tangent;
// Rather than evaluating the curve for the tangent, we derive
// it from the neighboring points. This gives us better
// behavior at the endpoints, where the tangent might go to
// zero.
if (j == 0) {
tangent = center_verts[vi + j + 1] - point;
} else if (j == length - 1) {
tangent = point - center_verts[vi + j - 1];
} else {
tangent = center_verts[vi + j + 1] - center_verts[vi + j - 1];
}
LVector3f cross = normalize(tangent.cross(camera_vec));
cross *= radius;
verts.push_back(point + cross);
verts.push_back(point - cross);
switch (uv_mode) {
case UV_none:
break;
case UV_parametric:
if (u_dominant) {
uvs.push_back(TexCoordf(t * uv_scale, 1.0f));
uvs.push_back(TexCoordf(t * uv_scale, 0.0f));
} else {
uvs.push_back(TexCoordf(1.0f, t * uv_scale));
uvs.push_back(TexCoordf(0.0f, t * uv_scale));
}
break;
CurveSegments::const_iterator si;
for (si = curve_segments.begin(); si != curve_segments.end(); ++si) {
const CurveSegment &segment = (*si);
case UV_distance:
if (j != 0) {
LVector3f vec = point - center_verts[vi + j - 1];
dist += vec.length();
}
if (u_dominant) {
uvs.push_back(TexCoordf(dist * uv_scale, 1.0f));
uvs.push_back(TexCoordf(dist * uv_scale, 0.0f));
} else {
uvs.push_back(TexCoordf(1.0f, dist * uv_scale));
uvs.push_back(TexCoordf(0.0f, dist * uv_scale));
}
break;
case UV_distance2:
if (j != 0) {
LVector3f vec = point - center_verts[vi + j - 1];
dist += vec.length_squared();
}
if (u_dominant) {
uvs.push_back(TexCoordf(dist * uv_scale, 1.0f));
uvs.push_back(TexCoordf(dist * uv_scale, 0.0f));
} else {
uvs.push_back(TexCoordf(1.0f, dist * uv_scale));
uvs.push_back(TexCoordf(0.0f, dist * uv_scale));
}
break;
}
}
vi += length;
lengths.push_back(length * 2);
lengths.push_back(segment.size() * 2);
num_prims++;
}
colors.push_back(Colorf(1.0f, 1.0f, 1.0f, 1.0f));
// And create a Geom for the rendering.
PT(Geom) geom = new GeomTristrip;
geom->set_num_prims(num_prims);
geom->set_coords(verts);
if (uv_mode != UV_none) {
if (get_uv_mode() != UV_none) {
geom->set_texcoords(uvs, G_PER_VERTEX);
}
geom->set_colors(colors, G_OVERALL);
if (get_use_vertex_color()) {
geom->set_colors(colors, G_PER_VERTEX);
} else {
geom->set_colors(colors, G_OVERALL);
}
geom->set_lengths(lengths);
CullableObject *object = new CullableObject(geom, data._state,
@ -520,6 +386,399 @@ render_billboard(CullTraverser *trav, CullTraverserData &data,
trav->get_cull_handler()->record_object(object);
}
////////////////////////////////////////////////////////////////////
// Function: RopeNode::render_tube
// Access: Private
// Description: Draws the rope in RM_tube mode. This draws a hollow
// tube centered around the string.
//
// In this mode, thickness is in spatial units, and
// determines the diameter of the tube.
////////////////////////////////////////////////////////////////////
void RopeNode::
render_tube(CullTraverser *trav, CullTraverserData &data,
NurbsCurveResult *result) const {
CurveSegments curve_segments;
get_connected_segments(curve_segments, result);
// Now, we build up a table of vertices, in a series of rings
// around the circumference of the tube.
int num_slices = get_num_slices();
int num_verts_per_slice;
PTA_Vertexf verts;
PTA_Normalf normals;
PTA_TexCoordf uvs;
PTA_Colorf colors;
compute_tube_vertices(verts, normals, uvs, colors,
num_verts_per_slice, curve_segments, result);
// Finally, go back one more time and build up the vindex array, to
// tie all the triangle strips together.
PTA_ushort vindex;
PTA_int lengths;
int num_prims = 0;
int vi = 0;
CurveSegments::const_iterator si;
for (si = curve_segments.begin(); si != curve_segments.end(); ++si) {
const CurveSegment &segment = (*si);
for (int s = 0; s < num_slices; ++s) {
int s1 = (s + 1) % num_verts_per_slice;
for (size_t j = 0; j < segment.size(); ++j) {
vindex.push_back((vi + j) * num_verts_per_slice + s);
vindex.push_back((vi + j) * num_verts_per_slice + s1);
}
lengths.push_back(segment.size() * 2);
num_prims++;
}
vi += (int)segment.size();
}
// And create a Geom for the rendering.
PT(Geom) geom = new GeomTristrip;
geom->set_num_prims(num_prims);
geom->set_coords(verts, vindex);
if (get_uv_mode() != UV_none) {
geom->set_texcoords(uvs, G_PER_VERTEX, vindex);
}
if (get_normal_mode() == NM_vertex) {
geom->set_normals(normals, G_PER_VERTEX, vindex);
}
if (get_use_vertex_color()) {
geom->set_colors(colors, G_PER_VERTEX, vindex);
} else {
geom->set_colors(colors, G_OVERALL);
}
geom->set_lengths(lengths);
CullableObject *object = new CullableObject(geom, data._state,
data._render_transform);
trav->get_cull_handler()->record_object(object);
}
////////////////////////////////////////////////////////////////////
// Function: RopeNode::get_connected_segments
// Access: Private
// Description: Evaluates the string of vertices along the curve, and
// also breaks them up into connected segments.
//
// Since the NurbsCurveEvaluator describes the curve as
// a sequence of possibly-connected piecewise continuous
// segments, this means joining together some adjacent
// segments from the NurbsCurveEvaluator into a single
// CurveSegment, if they happen to be connected (as most
// will be).
////////////////////////////////////////////////////////////////////
void RopeNode::
get_connected_segments(RopeNode::CurveSegments &curve_segments,
const NurbsCurveResult *result) const {
int num_verts = get_num_subdiv() + 1;
int num_segments = result->get_num_segments();
bool use_vertex_color = get_use_vertex_color();
CurveSegment *curve_segment = NULL;
LPoint3f last_point;
for (int segment = 0; segment < num_segments; ++segment) {
LPoint3f point;
result->eval_segment_point(segment, 0.0f, point);
if (curve_segment == (CurveSegment *)NULL ||
!point.almost_equal(last_point)) {
// If the first point of this segment is different from the last
// point of the previous segment, end the previous segment and
// begin a new one.
curve_segments.push_back(CurveSegment());
curve_segment = &curve_segments.back();
CurveVertex vtx;
vtx._p = point;
vtx._t = result->get_segment_t(segment, 0.0f);
if (use_vertex_color) {
result->eval_segment_extended_points(segment, 0.0f, 0, &vtx._c[0], 4);
}
curve_segment->push_back(vtx);
}
// Store all the remaining points in this segment.
for (int i = 1; i < num_verts; ++i) {
float t = (float)i / (float)(num_verts - 1);
CurveVertex vtx;
result->eval_segment_point(segment, t, vtx._p);
vtx._t = result->get_segment_t(segment, t);
if (use_vertex_color) {
result->eval_segment_extended_points(segment, t, 0, &vtx._c[0], 4);
}
curve_segment->push_back(vtx);
last_point = vtx._p;
}
}
}
////////////////////////////////////////////////////////////////////
// Function: RopeNode::compute_thread_vertices
// Access: Private
// Description: Calculates the vertices for a RM_thread render. This
// just copies the vertices more-or-less directly into
// the array.
////////////////////////////////////////////////////////////////////
void RopeNode::
compute_thread_vertices(PTA_Vertexf &verts, PTA_TexCoordf &uvs,
PTA_Colorf &colors,
const RopeNode::CurveSegments &curve_segments) const {
UVMode uv_mode = get_uv_mode();
float uv_scale = get_uv_scale();
bool u_dominant = get_uv_direction();
bool use_vertex_color = get_use_vertex_color();
float dist = 0.0f;
CurveSegments::const_iterator si;
for (si = curve_segments.begin(); si != curve_segments.end(); ++si) {
const CurveSegment &segment = (*si);
for (size_t j = 0; j < segment.size(); ++j) {
verts.push_back(segment[j]._p);
if (use_vertex_color) {
colors.push_back(segment[j]._c);
}
float uv_t = compute_uv_t(dist, uv_mode, uv_scale, segment, j);
if (uv_mode != UV_none) {
if (u_dominant) {
uvs.push_back(TexCoordf(uv_t, 0.0f));
} else {
uvs.push_back(TexCoordf(0.0f, uv_t));
}
}
}
}
if (!use_vertex_color) {
colors.push_back(Colorf(1.0f, 1.0f, 1.0f, 1.0f));
}
}
////////////////////////////////////////////////////////////////////
// Function: RopeNode::compute_billboard_vertices
// Access: Private
// Description: Calculates the vertices for a RM_billboard render. This
// puts a pair of vertices on either side of each
// computed point in curve_segments.
////////////////////////////////////////////////////////////////////
void RopeNode::
compute_billboard_vertices(PTA_Vertexf &verts, PTA_TexCoordf &uvs,
PTA_Colorf &colors, const LVector3f &camera_vec,
const RopeNode::CurveSegments &curve_segments,
NurbsCurveResult *result) const {
float thickness = get_thickness();
float radius = thickness * 0.5f;
UVMode uv_mode = get_uv_mode();
float uv_scale = get_uv_scale();
bool u_dominant = get_uv_direction();
bool use_vertex_color = get_use_vertex_color();
float dist = 0.0f;
CurveSegments::const_iterator si;
for (si = curve_segments.begin(); si != curve_segments.end(); ++si) {
const CurveSegment &segment = (*si);
for (size_t j = 0; j < segment.size(); ++j) {
LVector3f tangent;
compute_tangent(tangent, segment, j, result);
LVector3f normal = cross(tangent, camera_vec);
normal.normalize();
verts.push_back(segment[j]._p + normal * radius);
verts.push_back(segment[j]._p - normal * radius);
if (use_vertex_color) {
colors.push_back(segment[j]._c);
colors.push_back(segment[j]._c);
}
float uv_t = compute_uv_t(dist, uv_mode, uv_scale, segment, j);
if (uv_mode != UV_none) {
if (u_dominant) {
uvs.push_back(TexCoordf(uv_t, 1.0f));
uvs.push_back(TexCoordf(uv_t, 0.0f));
} else {
uvs.push_back(TexCoordf(1.0f, uv_t));
uvs.push_back(TexCoordf(0.0f, uv_t));
}
}
}
}
if (!use_vertex_color) {
colors.push_back(Colorf(1.0f, 1.0f, 1.0f, 1.0f));
}
}
////////////////////////////////////////////////////////////////////
// Function: RopeNode::compute_tube_vertices
// Access: Private
// Description: Calculates the vertices for a RM_tube render. This
// puts a ring of vertices around each computed point in
// curve_segments.
////////////////////////////////////////////////////////////////////
void RopeNode::
compute_tube_vertices(PTA_Vertexf &verts, PTA_Normalf &normals,
PTA_TexCoordf &uvs, PTA_Colorf &colors,
int &num_verts_per_slice,
const RopeNode::CurveSegments &curve_segments,
NurbsCurveResult *result) const {
int num_slices = get_num_slices();
num_verts_per_slice = num_slices;
float thickness = get_thickness();
float radius = thickness * 0.5f;
UVMode uv_mode = get_uv_mode();
float uv_scale = get_uv_scale();
bool u_dominant = get_uv_direction();
NormalMode normal_mode = get_normal_mode();
bool use_vertex_color = get_use_vertex_color();
// If we are generating UV's, we will need to duplicate the vertices
// along the seam so that the UV's go through the whole range of
// 0..1 instead of reflecting in the last polygon before the seam.
if (uv_mode != UV_none) {
++num_verts_per_slice;
}
LVector3f up = get_tube_up();
float dist = 0.0f;
CurveSegments::const_iterator si;
for (si = curve_segments.begin(); si != curve_segments.end(); ++si) {
const CurveSegment &segment = (*si);
for (size_t j = 0; j < segment.size(); ++j) {
LVector3f tangent;
compute_tangent(tangent, segment, j, result);
LVector3f normal = cross(tangent, up);
normal.normalize();
up = cross(normal, tangent);
LMatrix3f rotate = LMatrix3f::rotate_mat(360.0f / (float)num_slices,
tangent);
float uv_t = compute_uv_t(dist, uv_mode, uv_scale, segment, j);
for (int s = 0; s < num_verts_per_slice; ++s) {
verts.push_back(segment[j]._p + normal * radius);
if (normal_mode == NM_vertex) {
normals.push_back(normal);
}
if (use_vertex_color) {
colors.push_back(segment[j]._c);
}
normal = normal * rotate;
if (uv_mode != UV_none) {
float uv_s = (float)s / (float)num_slices;
if (u_dominant) {
uvs.push_back(TexCoordf(uv_t, uv_s));
} else {
uvs.push_back(TexCoordf(uv_s, uv_t));
}
}
}
}
}
if (!use_vertex_color) {
colors.push_back(Colorf(1.0f, 1.0f, 1.0f, 1.0f));
}
}
////////////////////////////////////////////////////////////////////
// Function: RopeNode::compute_tangent
// Access: Private, Static
// Description: Computes the tangent to the curve at the indicated
// point in the segment.
////////////////////////////////////////////////////////////////////
void RopeNode::
compute_tangent(LVector3f &tangent, const RopeNode::CurveSegment &segment,
size_t j, NurbsCurveResult *result) {
// First, try to evaluate the tangent at the curve. This gives
// better results at the ends at the endpoints where the tangent
// does not go to zero.
/*
Actually, on second thought this looks terrible.
if (result->eval_tangent(segment[j]._t, tangent)) {
if (!tangent.almost_equal(LVector3f::zero())) {
return;
}
}
*/
// If that failed (or produced a zero tangent), then derive the
// tangent from the neighboring points instead.
if (j == 0) {
tangent = segment[j + 1]._p - segment[j]._p;
} else if (j == segment.size() - 1) {
tangent = segment[j]._p - segment[j - 1]._p;
} else {
tangent = segment[j + 1]._p - segment[j - 1]._p;
}
}
////////////////////////////////////////////////////////////////////
// Function: RopeNode::compute_uv_t
// Access: Private, Static
// Description: Computes the texture coordinate along the curve for
// the indicated point in the segment.
////////////////////////////////////////////////////////////////////
float RopeNode::
compute_uv_t(float &dist, const RopeNode::UVMode &uv_mode,
float uv_scale, const RopeNode::CurveSegment &segment,
size_t j) {
switch (uv_mode) {
case UV_none:
return 0.0f;
case UV_parametric:
return segment[j]._t * uv_scale;
case UV_distance:
if (j != 0) {
LVector3f vec = segment[j]._p - segment[j - 1]._p;
dist += vec.length();
}
return dist * uv_scale;
case UV_distance2:
if (j != 0) {
LVector3f vec = segment[j]._p - segment[j - 1]._p;
dist += vec.length_squared();
}
return dist * uv_scale;
}
return 0.0f;
}
////////////////////////////////////////////////////////////////////
// Function: RopeNode::register_with_read_factory
// Access: Public, Static

65
panda/src/parametrics/ropeNode.h
View File

@ -59,7 +59,10 @@ PUBLISHED:
// Render the rope as a continuous triangle strip oriented to be
// perpendicular to the view vector.
RM_billboard
RM_billboard,
// Render the rope as a hollow tube extruded along its length.
RM_tube
};
enum UVMode {
@ -83,6 +86,14 @@ PUBLISHED:
UV_distance2,
};
enum NormalMode {
// Don't generate normals.
NM_none,
// Generate vertex (smooth-shaded) normals.
NM_vertex
};
INLINE void set_curve(NurbsCurveEvaluator *curve);
INLINE NurbsCurveEvaluator *get_curve() const;
@ -95,16 +106,24 @@ PUBLISHED:
INLINE void set_uv_direction(bool u_dominant);
INLINE bool get_uv_direction() const;
INLINE void set_uv_scale(const LVecBase2f &uv_scale);
INLINE void set_uv_scale(float scale);
INLINE float get_uv_scale() const;
INLINE void set_normal_mode(NormalMode normal_mode);
INLINE NormalMode get_normal_mode() const;
INLINE void set_tube_up(const LVector3f &tube_up);
INLINE const LVector3f &get_tube_up() const;
INLINE void set_use_vertex_color(bool flag);
INLINE bool get_use_vertex_color() const;
INLINE void set_num_subdiv(int num_subdiv);
INLINE int get_num_subdiv() const;
INLINE void set_num_slices(int num_slices);
INLINE int get_num_slices() const;
INLINE void set_thickness(float thickness);
INLINE float get_thickness() const;
@ -116,9 +135,44 @@ protected:
private:
BoundingVolume *do_recompute_bound(const NodePath &rel_to);
void render_thread(CullTraverser *trav, CullTraverserData &data,
NurbsCurveResult *result);
NurbsCurveResult *result) const;
void render_billboard(CullTraverser *trav, CullTraverserData &data,
NurbsCurveResult *result);
NurbsCurveResult *result) const;
void render_tube(CullTraverser *trav, CullTraverserData &data,
NurbsCurveResult *result) const;
class CurveVertex {
public:
LPoint3f _p;
Colorf _c;
float _t;
};
typedef pvector<CurveVertex> CurveSegment;
typedef pvector<CurveSegment> CurveSegments;
void get_connected_segments(CurveSegments &curve_segments,
const NurbsCurveResult *result) const;
void compute_thread_vertices(PTA_Vertexf &verts, PTA_TexCoordf &uvs,
PTA_Colorf &colors,
const CurveSegments &curve_segments) const;
void compute_billboard_vertices(PTA_Vertexf &verts, PTA_TexCoordf &uvs,
PTA_Colorf &colors,
const LVector3f &camera_vec,
const CurveSegments &curve_segments,
NurbsCurveResult *result) const;
void compute_tube_vertices(PTA_Vertexf &verts, PTA_Normalf &normals,
PTA_TexCoordf &uvs, PTA_Colorf &colors,
int &num_verts_per_slice,
const CurveSegments &curve_segments,
NurbsCurveResult *result) const;
static void compute_tangent(LVector3f &tangent, const CurveSegment &segment,
size_t j, NurbsCurveResult *result);
static float compute_uv_t(float &dist, const UVMode &uv_mode,
float uv_scale, const CurveSegment &segment,
size_t j);
private:
// This is the data that must be cycled between pipeline stages.
@ -135,8 +189,11 @@ private:
UVMode _uv_mode;
bool _u_dominant;
float _uv_scale;
NormalMode _normal_mode;
LVector3f _tube_up;
bool _use_vertex_color;
int _num_subdiv;
int _num_slices;
float _thickness;
};