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Fix #32904: strange pattern on subdivided cube with anistropic shader. Now

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tangents from generated coordinates are computed per pixel on the fly, avoids
bad interpolation of singularities.
This commit is contained in:
Brecht Van Lommel
2012-10-17 23:09:12 +00:00
parent b2142d6533
commit 9d260eedeb
4 changed files with 37 additions and 77 deletions
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73
intern/cycles/blender/blender_mesh.cpp
View File

@@ -33,22 +33,6 @@ CCL_NAMESPACE_BEGIN
/* Find/Add */
static float3 tangent_uv_from_generated(float3 P)
{
float length = len(P);
if(length == 0.0f)
return make_float3(0.0f, 0.0f, 0.0f);
float u = 0.0f;
if(!(P.x == 0.0f && P.y == 0.0f))
u = (1.0f - atan2f(P.x, P.y))/(2.0f*M_PI_F);
float v = 1.0f - acosf(clamp(P.z/length, -1.0f, 1.0f))/M_PI_F;
return make_float3(u, v, 0.0f);
}
static float3 tangent_from_triangle(float3 v0, float3 v1, float3 v2, float3 tx0, float3 tx1, float3 tx2)
{
float3 duv1 = tx2 - tx0;
@@ -176,9 +160,7 @@ static void create_mesh(Scene *scene, Mesh *mesh, BL::Mesh b_mesh, const vector<
}
/* create texcoord-based tangent attributes */
bool need_tangent = mesh->need_attribute(scene, ATTR_STD_TANGENT);
if(need_tangent) {
if(mesh->need_attribute(scene, ATTR_STD_TANGENT)) {
BL::Mesh::tessface_uv_textures_iterator l;
for(b_mesh.tessface_uv_textures.begin(l); l != b_mesh.tessface_uv_textures.end(); ++l) {
@@ -233,15 +215,13 @@ static void create_mesh(Scene *scene, Mesh *mesh, BL::Mesh b_mesh, const vector<
/* normalize tangent vectors */
for(int i = 0; i < mesh->verts.size(); i++)
tangents[i] = normalize(tangents[i]);
need_tangent = false;
}
}
/* create generated coordinates. todo: we should actually get the orco
* coordinates from modifiers, for now we use texspace loc/size which
* is available in the api. */
if(mesh->need_attribute(scene, ATTR_STD_GENERATED) || need_tangent) {
if(mesh->need_attribute(scene, ATTR_STD_GENERATED)) {
Attribute *attr = mesh->attributes.add(ATTR_STD_GENERATED);
float3 loc = get_float3(b_mesh.texspace_location());
float3 size = get_float3(b_mesh.texspace_size());
@@ -257,55 +237,6 @@ static void create_mesh(Scene *scene, Mesh *mesh, BL::Mesh b_mesh, const vector<
for(b_mesh.vertices.begin(v); v != b_mesh.vertices.end(); ++v)
generated[i++] = get_float3(v->co())*size - loc;
/* if there is no UV map, we generated tangents from generated coordinates */
if(need_tangent) {
Attribute *attr = mesh->attributes.add(ATTR_STD_TANGENT, ustring("Tangent"));
/* compute average tangents per vertex */
float3 *tangents = attr->data_float3();
memset(tangents, 0, sizeof(float3)*mesh->verts.size());
size_t fi = 0; /* face index */
for(b_mesh.tessfaces.begin(f); f != b_mesh.tessfaces.end(); ++fi, ++f) {
int4 vi = get_int4(f->vertices_raw());
float3 tx0 = tangent_uv_from_generated(generated[vi[0]]);
float3 tx1 = tangent_uv_from_generated(generated[vi[1]]);
float3 tx2 = tangent_uv_from_generated(generated[vi[2]]);
float3 v0 = mesh->verts[vi[0]];
float3 v1 = mesh->verts[vi[1]];
float3 v2 = mesh->verts[vi[2]];
/* calculate tangent for the triangle;
* get vertex positions, and find change in position with respect
* to the texture coords in the first texture coord dimension */
float3 tangent0 = tangent_from_triangle(v0, v1, v2, tx0, tx1, tx2);
if(nverts[fi] == 4) {
/* quad tangent */
float3 tx3 = tangent_uv_from_generated(generated[vi[3]]);
float3 v3 = mesh->verts[vi[3]];
float3 tangent1 = tangent_from_triangle(v0, v2, v3, tx0, tx2, tx3);
tangents[vi[0]] += 0.5f*(tangent0 + tangent1);
tangents[vi[1]] += tangent0;
tangents[vi[2]] += 0.5f*(tangent0 + tangent1);
tangents[vi[3]] += tangent1;
}
else {
/* triangle tangent */
tangents[vi[0]] += tangent0;
tangents[vi[1]] += tangent0;
tangents[vi[2]] += tangent0;
}
}
/* normalize tangent vectors */
for(int i = 0; i < mesh->verts.size(); i++)
tangents[i] = normalize(tangents[i]);
}
}
}

4
intern/cycles/kernel/svm/bsdf_ward.h
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@@ -39,8 +39,8 @@ CCL_NAMESPACE_BEGIN
__device void bsdf_ward_setup(ShaderData *sd, ShaderClosure *sc, float ax, float ay)
{
float m_ax = clamp(ax, 1e-5f, 1.0f);
float m_ay = clamp(ay, 1e-5f, 1.0f);
float m_ax = clamp(ax, 1e-4f, 1.0f);
float m_ay = clamp(ay, 1e-4f, 1.0f);
sc->data0 = m_ax;
sc->data1 = m_ay;

29
intern/cycles/kernel/svm/svm_geometry.h
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@@ -20,6 +20,22 @@ CCL_NAMESPACE_BEGIN
/* Geometry Node */
__device_inline float3 svm_tangent_from_generated(float3 P)
{
float length = len(P);
if(length == 0.0f)
return make_float3(0.0f, 0.0f, 0.0f);
float u = 0.0f;
if(!(P.x == 0.0f && P.y == 0.0f))
u = (1.0f - atan2f(P.x, P.y))/(2.0f*M_PI_F);
float v = 1.0f - acosf(clamp(P.z/length, -1.0f, 1.0f))/M_PI_F;
return make_float3(u, v, 0.0f);
}
__device void svm_node_geometry(KernelGlobals *kg, ShaderData *sd, float *stack, uint type, uint out_offset)
{
float3 data;
@@ -36,8 +52,17 @@ __device void svm_node_geometry(KernelGlobals *kg, ShaderData *sd, float *stack,
data = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_VERTEX, attr_offset, NULL, NULL);
object_normal_transform(kg, sd, &data);
}
else
data = normalize(sd->dPdu);
else {
attr_offset = find_attribute(kg, sd, ATTR_STD_GENERATED);
if(attr_offset != ATTR_STD_NOT_FOUND) {
data = triangle_attribute_float3(kg, sd, ATTR_ELEMENT_VERTEX, attr_offset, NULL, NULL);
svm_tangent_from_generated(data);
object_normal_transform(kg, sd, &data);
}
else
data = normalize(sd->dPdu);
}
}
else
data = normalize(sd->dPdu);

8
intern/cycles/render/nodes.cpp
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@@ -1246,8 +1246,10 @@ void WardBsdfNode::attributes(AttributeRequestSet *attributes)
{
ShaderInput *tangent_in = input("Tangent");
if(!tangent_in->link)
if(!tangent_in->link) {
attributes->add(ATTR_STD_TANGENT);
attributes->add(ATTR_STD_GENERATED);
}
ShaderNode::attributes(attributes);
}
@@ -1595,8 +1597,10 @@ GeometryNode::GeometryNode()
void GeometryNode::attributes(AttributeRequestSet *attributes)
{
if(!output("Tangent")->links.empty())
if(!output("Tangent")->links.empty()) {
attributes->add(ATTR_STD_TANGENT);
attributes->add(ATTR_STD_GENERATED);
}
ShaderNode::attributes(attributes);
}