mesh.cpp

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/*
 * Copyright 2011, Blender Foundation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "bvh.h"
#include "bvh_build.h"

#include "device.h"
#include "shader.h"
#include "light.h"
#include "mesh.h"
#include "object.h"
#include "scene.h"

#include "osl_globals.h"

#include "util_cache.h"
#include "util_foreach.h"
#include "util_progress.h"
#include "util_set.h"

CCL_NAMESPACE_BEGIN

/* Mesh */

Mesh::Mesh()
: attributes(this)
{
    need_update = true;
    transform_applied = false;
    transform_negative_scaled = false;
    displacement_method = DISPLACE_BUMP;

    bvh = NULL;

    tri_offset = 0;
    vert_offset = 0;
}

Mesh::~Mesh()
{
    delete bvh;
}

void Mesh::reserve(int numverts, int numtris)
{
    /* reserve space to add verts and triangles later */
    verts.resize(numverts);
    triangles.resize(numtris);
    shader.resize(numtris);
    smooth.resize(numtris);
    attributes.reserve(numverts, numtris);
}

void Mesh::clear()
{
    /* clear all verts and triangles */
    verts.clear();
    triangles.clear();
    shader.clear();
    smooth.clear();

    attributes.clear();
    used_shaders.clear();

    transform_applied = false;
    transform_negative_scaled = false;
}

void Mesh::add_triangle(int v0, int v1, int v2, int shader_, bool smooth_)
{
    Triangle t;
    t.v[0] = v0;
    t.v[1] = v1;
    t.v[2] = v2;

    triangles.push_back(t);
    shader.push_back(shader_);
    smooth.push_back(smooth_);
}

void Mesh::compute_bounds()
{
    BoundBox bnds;
    size_t verts_size = verts.size();

    for(size_t i = 0; i < verts_size; i++)
        bnds.grow(verts[i]);

    /* happens mostly on empty meshes */
    if(!bnds.valid())
        bnds.grow(make_float3(0.0f, 0.0f, 0.0f));

    bounds = bnds;
}

void Mesh::add_face_normals()
{
    /* don't compute if already there */
    if(attributes.find(Attribute::STD_FACE_NORMAL))
        return;

    /* get attributes */
    Attribute *attr_fN = attributes.add(Attribute::STD_FACE_NORMAL);
    float3 *fN = attr_fN->data_float3();

    /* compute face normals */
    size_t triangles_size = triangles.size();
    bool flip = transform_negative_scaled;

    if(triangles_size) {
        float3 *verts_ptr = &verts[0];
        Triangle *triangles_ptr = &triangles[0];

        for(size_t i = 0; i < triangles_size; i++) {
            Triangle t = triangles_ptr[i];
            float3 v0 = verts_ptr[t.v[0]];
            float3 v1 = verts_ptr[t.v[1]];
            float3 v2 = verts_ptr[t.v[2]];

            fN[i] = normalize(cross(v1 - v0, v2 - v0));

            if(flip)
                fN[i] = -fN[i];
        }
    }
}

void Mesh::add_vertex_normals()
{
    /* don't compute if already there */
    if(attributes.find(Attribute::STD_VERTEX_NORMAL))
        return;

    /* get attributes */
    Attribute *attr_fN = attributes.find(Attribute::STD_FACE_NORMAL);
    Attribute *attr_vN = attributes.add(Attribute::STD_VERTEX_NORMAL);

    float3 *fN = attr_fN->data_float3();
    float3 *vN = attr_vN->data_float3();

    /* compute vertex normals */
    memset(vN, 0, verts.size()*sizeof(float3));

    size_t verts_size = verts.size();
    size_t triangles_size = triangles.size();
    bool flip = transform_negative_scaled;

    if(triangles_size) {
        Triangle *triangles_ptr = &triangles[0];

        for(size_t i = 0; i < triangles_size; i++)
            for(size_t j = 0; j < 3; j++)
                vN[triangles_ptr[i].v[j]] += fN[i];
    }

    for(size_t i = 0; i < verts_size; i++) {
        vN[i] = normalize(vN[i]);
        if(flip)
            vN[i] = -vN[i];
    }
}

void Mesh::pack_normals(Scene *scene, float4 *normal, float4 *vnormal)
{
    Attribute *attr_fN = attributes.find(Attribute::STD_FACE_NORMAL);
    Attribute *attr_vN = attributes.find(Attribute::STD_VERTEX_NORMAL);

    float3 *fN = attr_fN->data_float3();
    float3 *vN = attr_vN->data_float3();
    int shader_id = 0;
    uint last_shader = -1;
    bool last_smooth = false;

    size_t triangles_size = triangles.size();
    uint *shader_ptr = (shader.size())? &shader[0]: NULL;

    for(size_t i = 0; i < triangles_size; i++) {
        normal[i].x = fN[i].x;
        normal[i].y = fN[i].y;
        normal[i].z = fN[i].z;

        /* stuff shader id in here too */
        if(shader_ptr[i] != last_shader || last_smooth != smooth[i]) {
            last_shader = shader_ptr[i];
            last_smooth = smooth[i];
            shader_id = scene->shader_manager->get_shader_id(last_shader, this, last_smooth);
        }

        normal[i].w = __int_as_float(shader_id);
    }

    size_t verts_size = verts.size();

    for(size_t i = 0; i < verts_size; i++)
        vnormal[i] = make_float4(vN[i].x, vN[i].y, vN[i].z, 0.0f);
}

void Mesh::pack_verts(float4 *tri_verts, float4 *tri_vindex, size_t vert_offset)
{
    size_t verts_size = verts.size();

    if(verts_size) {
        float3 *verts_ptr = &verts[0];

        for(size_t i = 0; i < verts_size; i++) {
            float3 p = verts_ptr[i];
            tri_verts[i] = make_float4(p.x, p.y, p.z, 0.0f);
        }
    }

    size_t triangles_size = triangles.size();

    if(triangles_size) {
        Triangle *triangles_ptr = &triangles[0];

        for(size_t i = 0; i < triangles_size; i++) {
            Triangle t = triangles_ptr[i];

            tri_vindex[i] = make_float4(
                __int_as_float(t.v[0] + vert_offset),
                __int_as_float(t.v[1] + vert_offset),
                __int_as_float(t.v[2] + vert_offset),
                0);
        }
    }
}

void Mesh::compute_bvh(SceneParams *params, Progress& progress)
{
    Object object;
    object.mesh = this;

    vector<Object*> objects;
    objects.push_back(&object);

    if(bvh && !need_update_rebuild) {
        progress.set_substatus("Refitting BVH");
        bvh->objects = objects;
        bvh->refit(progress);
    }
    else {
        progress.set_substatus("Building BVH");

        BVHParams bparams;
        bparams.use_cache = params->use_bvh_cache;
        bparams.use_spatial_split = params->use_bvh_spatial_split;
        bparams.use_qbvh = params->use_qbvh;

        delete bvh;
        bvh = BVH::create(bparams, objects);
        bvh->build(progress);
    }
}

void Mesh::tag_update(Scene *scene, bool rebuild)
{
    need_update = true;

    if(rebuild) {
        need_update_rebuild = true;
        scene->light_manager->need_update = true;
    }
    else {
        foreach(uint sindex, used_shaders)
            if(scene->shaders[sindex]->has_surface_emission)
                scene->light_manager->need_update = true;
    }

    scene->mesh_manager->need_update = true;
    scene->object_manager->need_update = true;
}

/* Mesh Manager */

MeshManager::MeshManager()
{
    bvh = NULL;
    need_update = true;
}

MeshManager::~MeshManager()
{
    delete bvh;
}

void MeshManager::update_osl_attributes(Device *device, Scene *scene, vector<AttributeRequestSet>& mesh_attributes)
{
#ifdef WITH_OSL
    /* for OSL, a hash map is used to lookup the attribute by name. */
    OSLGlobals *og = (OSLGlobals*)device->osl_memory();

    og->object_name_map.clear();
    og->attribute_map.clear();

    og->attribute_map.resize(scene->objects.size());

    for(size_t i = 0; i < scene->objects.size(); i++) {
        /* set object name to object index map */
        Object *object = scene->objects[i];
        og->object_name_map[object->name] = i;

        /* set object attributes */
        foreach(ParamValue& attr, object->attributes) {
            OSLGlobals::Attribute osl_attr;

            osl_attr.type = attr.type();
            osl_attr.elem = ATTR_ELEMENT_VALUE;
            osl_attr.value = attr;

            og->attribute_map[i][attr.name()] = osl_attr;
        }

        /* find mesh attributes */
        size_t j;

        for(j = 0; j < scene->meshes.size(); j++)
            if(scene->meshes[j] == object->mesh)
                break;

        AttributeRequestSet& attributes = mesh_attributes[j];

        /* set object attributes */
        foreach(AttributeRequest& req, attributes.requests) {
            OSLGlobals::Attribute osl_attr;

            osl_attr.elem = req.element;
            osl_attr.offset = req.offset;

            if(req.type == TypeDesc::TypeFloat)
                osl_attr.type = TypeDesc::TypeFloat;
            else
                osl_attr.type = TypeDesc::TypeColor;

            if(req.std != Attribute::STD_NONE) {
                /* if standard attribute, add lookup by std:: name convention */
                ustring stdname = ustring(string("std::") + Attribute::standard_name(req.std).c_str());
                og->attribute_map[i][stdname] = osl_attr;
            }
            else if(req.name != ustring()) {
                /* add lookup by mesh attribute name */
                og->attribute_map[i][req.name] = osl_attr;
            }
        }
    }
#endif
}

void MeshManager::update_svm_attributes(Device *device, DeviceScene *dscene, Scene *scene, vector<AttributeRequestSet>& mesh_attributes)
{
    /* for SVM, the attributes_map table is used to lookup the offset of an
     * attribute, based on a unique shader attribute id. */

    /* compute array stride */
    int attr_map_stride = 0;

    for(size_t i = 0; i < scene->meshes.size(); i++)
        attr_map_stride = max(attr_map_stride, mesh_attributes[i].size());

    if(attr_map_stride == 0)
        return;
    
    /* create attribute map */
    uint4 *attr_map = dscene->attributes_map.resize(attr_map_stride*scene->objects.size());
    memset(attr_map, 0, dscene->attributes_map.size()*sizeof(uint));

    for(size_t i = 0; i < scene->objects.size(); i++) {
        Object *object = scene->objects[i];

        /* find mesh attributes */
        size_t j;

        for(j = 0; j < scene->meshes.size(); j++)
            if(scene->meshes[j] == object->mesh)
                break;

        AttributeRequestSet& attributes = mesh_attributes[j];

        /* set object attributes */
        j = 0;

        foreach(AttributeRequest& req, attributes.requests) {
            int index = i*attr_map_stride + j;
            uint id;

            if(req.std == Attribute::STD_NONE)
                id = scene->shader_manager->get_attribute_id(req.name);
            else
                id = scene->shader_manager->get_attribute_id(req.std);

            attr_map[index].x = id;
            attr_map[index].y = req.element;
            attr_map[index].z = req.offset;

            if(req.type == TypeDesc::TypeFloat)
                attr_map[index].w = NODE_ATTR_FLOAT;
            else
                attr_map[index].w = NODE_ATTR_FLOAT3;

            j++;
        }
    }

    /* copy to device */
    dscene->data.bvh.attributes_map_stride = attr_map_stride;
    device->tex_alloc("__attributes_map", dscene->attributes_map);
}

void MeshManager::device_update_attributes(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
    progress.set_status("Updating Mesh", "Computing attributes");

    /* gather per mesh requested attributes. as meshes may have multiple
     * shaders assigned, this merges the requested attributes that have
     * been set per shader by the shader manager */
    vector<AttributeRequestSet> mesh_attributes(scene->meshes.size());

    for(size_t i = 0; i < scene->meshes.size(); i++) {
        Mesh *mesh = scene->meshes[i];

        foreach(uint sindex, mesh->used_shaders) {
            Shader *shader = scene->shaders[sindex];
            mesh_attributes[i].add(shader->attributes);
        }
    }

    /* mesh attribute are stored in a single array per data type. here we fill
     * those arrays, and set the offset and element type to create attribute
     * maps next */
    vector<float> attr_float;
    vector<float4> attr_float3;

    for(size_t i = 0; i < scene->meshes.size(); i++) {
        Mesh *mesh = scene->meshes[i];
        AttributeRequestSet& attributes = mesh_attributes[i];

        /* todo: we now store std and name attributes from requests even if
           they actually refer to the same mesh attributes, optimize */
        foreach(AttributeRequest& req, attributes.requests) {
            Attribute *mattr = mesh->attributes.find(req);

            /* todo: get rid of this exception */
            if(!mattr && req.std == Attribute::STD_GENERATED) {
                mattr = mesh->attributes.add(Attribute::STD_GENERATED);
                if(mesh->verts.size())
                    memcpy(mattr->data_float3(), &mesh->verts[0], sizeof(float3)*mesh->verts.size());
            }

            /* attribute not found */
            if(!mattr) {
                req.element = ATTR_ELEMENT_NONE;
                req.offset = 0;
                continue;
            }

            /* we abuse AttributeRequest to pass on info like element and
               offset, it doesn't really make sense but is convenient */

            /* store element and type */
            if(mattr->element == Attribute::VERTEX)
                req.element = ATTR_ELEMENT_VERTEX;
            else if(mattr->element == Attribute::FACE)
                req.element = ATTR_ELEMENT_FACE;
            else if(mattr->element == Attribute::CORNER)
                req.element = ATTR_ELEMENT_CORNER;

            req.type = mattr->type;

            /* store attribute data in arrays */
            size_t size = mattr->element_size(mesh->verts.size(), mesh->triangles.size());

            if(mattr->type == TypeDesc::TypeFloat) {
                float *data = mattr->data_float();
                req.offset = attr_float.size();

                for(size_t k = 0; k < size; k++)
                    attr_float.push_back(data[k]);
            }
            else {
                float3 *data = mattr->data_float3();
                req.offset = attr_float3.size();

                for(size_t k = 0; k < size; k++) {
                    float3 f3 = data[k];
                    float4 f4 = make_float4(f3.x, f3.y, f3.z, 0.0f);

                    attr_float3.push_back(f4);
                }
            }

            /* mesh vertex/triangle index is global, not per object, so we sneak
               a correction for that in here */
            if(req.element == ATTR_ELEMENT_VERTEX)
                req.offset -= mesh->vert_offset;
            else if(mattr->element == Attribute::FACE)
                req.offset -= mesh->tri_offset;
            else if(mattr->element == Attribute::CORNER)
                req.offset -= 3*mesh->tri_offset;

            if(progress.get_cancel()) return;
        }
    }

    /* create attribute lookup maps */
    if(scene->params.shadingsystem == SceneParams::OSL)
        update_osl_attributes(device, scene, mesh_attributes);
    else
        update_svm_attributes(device, dscene, scene, mesh_attributes);

    if(progress.get_cancel()) return;

    /* copy to device */
    progress.set_status("Updating Mesh", "Copying Attributes to device");

    if(attr_float.size()) {
        dscene->attributes_float.copy(&attr_float[0], attr_float.size());
        device->tex_alloc("__attributes_float", dscene->attributes_float);
    }
    if(attr_float3.size()) {
        dscene->attributes_float3.copy(&attr_float3[0], attr_float3.size());
        device->tex_alloc("__attributes_float3", dscene->attributes_float3);
    }
}

void MeshManager::device_update_mesh(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
    /* count and update offsets */
    size_t vert_size = 0;
    size_t tri_size = 0;

    foreach(Mesh *mesh, scene->meshes) {
        mesh->vert_offset = vert_size;
        mesh->tri_offset = tri_size;

        vert_size += mesh->verts.size();
        tri_size += mesh->triangles.size();
    }

    if(tri_size == 0)
        return;

    /* normals */
    progress.set_status("Updating Mesh", "Computing normals");

    float4 *normal = dscene->tri_normal.resize(tri_size);
    float4 *vnormal = dscene->tri_vnormal.resize(vert_size);
    float4 *tri_verts = dscene->tri_verts.resize(vert_size);
    float4 *tri_vindex = dscene->tri_vindex.resize(tri_size);

    foreach(Mesh *mesh, scene->meshes) {
        mesh->pack_normals(scene, &normal[mesh->tri_offset], &vnormal[mesh->vert_offset]);
        mesh->pack_verts(&tri_verts[mesh->vert_offset], &tri_vindex[mesh->tri_offset], mesh->vert_offset);

        if(progress.get_cancel()) return;
    }

    /* vertex coordinates */
    progress.set_status("Updating Mesh", "Copying Mesh to device");

    device->tex_alloc("__tri_normal", dscene->tri_normal);
    device->tex_alloc("__tri_vnormal", dscene->tri_vnormal);
    device->tex_alloc("__tri_verts", dscene->tri_verts);
    device->tex_alloc("__tri_vindex", dscene->tri_vindex);
}

void MeshManager::device_update_bvh(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
    /* bvh build */
    progress.set_status("Updating Scene BVH", "Building");

    BVHParams bparams;
    bparams.top_level = true;
    bparams.use_qbvh = scene->params.use_qbvh;
    bparams.use_spatial_split = scene->params.use_bvh_spatial_split;
    bparams.use_cache = scene->params.use_bvh_cache;

    delete bvh;
    bvh = BVH::create(bparams, scene->objects);
    bvh->build(progress);

    if(progress.get_cancel()) return;

    /* copy to device */
    progress.set_status("Updating Scene BVH", "Copying BVH to device");

    PackedBVH& pack = bvh->pack;

    if(pack.nodes.size()) {
        dscene->bvh_nodes.reference((float4*)&pack.nodes[0], pack.nodes.size());
        device->tex_alloc("__bvh_nodes", dscene->bvh_nodes);
    }
    if(pack.object_node.size()) {
        dscene->object_node.reference((uint*)&pack.object_node[0], pack.object_node.size());
        device->tex_alloc("__object_node", dscene->object_node);
    }
    if(pack.tri_woop.size()) {
        dscene->tri_woop.reference(&pack.tri_woop[0], pack.tri_woop.size());
        device->tex_alloc("__tri_woop", dscene->tri_woop);
    }
    if(pack.prim_visibility.size()) {
        dscene->prim_visibility.reference((uint*)&pack.prim_visibility[0], pack.prim_visibility.size());
        device->tex_alloc("__prim_visibility", dscene->prim_visibility);
    }
    if(pack.prim_index.size()) {
        dscene->prim_index.reference((uint*)&pack.prim_index[0], pack.prim_index.size());
        device->tex_alloc("__prim_index", dscene->prim_index);
    }
    if(pack.prim_object.size()) {
        dscene->prim_object.reference((uint*)&pack.prim_object[0], pack.prim_object.size());
        device->tex_alloc("__prim_object", dscene->prim_object);
    }

    dscene->data.bvh.root = pack.root_index;
}

void MeshManager::device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
    if(!need_update)
        return;

    /* update normals */
    foreach(Mesh *mesh, scene->meshes) {
        foreach(uint shader, mesh->used_shaders)
            if(scene->shaders[shader]->need_update_attributes)
                mesh->need_update = true;

        if(mesh->need_update) {
            mesh->add_face_normals();
            mesh->add_vertex_normals();

            if(progress.get_cancel()) return;
        }
    }

    /* device update */
    device_free(device, dscene);

    device_update_mesh(device, dscene, scene, progress);
    if(progress.get_cancel()) return;

    device_update_attributes(device, dscene, scene, progress);
    if(progress.get_cancel()) return;

    /* update displacement */
    bool displacement_done = false;

    foreach(Mesh *mesh, scene->meshes)
        if(mesh->need_update && displace(device, scene, mesh, progress))
            displacement_done = true;

    /* todo: properly handle cancel halfway displacement */
    if(progress.get_cancel()) return;

    /* device re-update after displacement */
    if(displacement_done) {
        device_free(device, dscene);

        device_update_mesh(device, dscene, scene, progress);
        if(progress.get_cancel()) return;

        device_update_attributes(device, dscene, scene, progress);
        if(progress.get_cancel()) return;
    }

    /* update bvh */
    size_t i = 0, num_instance_bvh = 0;

    foreach(Mesh *mesh, scene->meshes)
        if(mesh->need_update && !mesh->transform_applied)
            num_instance_bvh++;

    foreach(Mesh *mesh, scene->meshes) {
        if(mesh->need_update) {
            mesh->compute_bounds();

            if(!mesh->transform_applied) {
                string msg = "Updating Mesh BVH ";
                if(mesh->name == "")
                    msg += string_printf("%u/%u", (uint)(i+1), (uint)num_instance_bvh);
                else
                    msg += string_printf("%s %u/%u", mesh->name.c_str(), (uint)(i+1), (uint)num_instance_bvh);
                progress.set_status(msg, "Building BVH");

                mesh->compute_bvh(&scene->params, progress);
            }

            if(progress.get_cancel()) return;

            mesh->need_update = false;
            mesh->need_update_rebuild = false;
        }

        i++;
    }
    
    foreach(Shader *shader, scene->shaders)
        shader->need_update_attributes = false;

    foreach(Object *object, scene->objects)
        object->compute_bounds();

    if(progress.get_cancel()) return;

    device_update_bvh(device, dscene, scene, progress);

    need_update = false;
}

void MeshManager::device_free(Device *device, DeviceScene *dscene)
{
    device->tex_free(dscene->bvh_nodes);
    device->tex_free(dscene->object_node);
    device->tex_free(dscene->tri_woop);
    device->tex_free(dscene->prim_visibility);
    device->tex_free(dscene->prim_index);
    device->tex_free(dscene->prim_object);
    device->tex_free(dscene->tri_normal);
    device->tex_free(dscene->tri_vnormal);
    device->tex_free(dscene->tri_vindex);
    device->tex_free(dscene->tri_verts);
    device->tex_free(dscene->attributes_map);
    device->tex_free(dscene->attributes_float);
    device->tex_free(dscene->attributes_float3);

    dscene->bvh_nodes.clear();
    dscene->object_node.clear();
    dscene->tri_woop.clear();
    dscene->prim_visibility.clear();
    dscene->prim_index.clear();
    dscene->prim_object.clear();
    dscene->tri_normal.clear();
    dscene->tri_vnormal.clear();
    dscene->tri_vindex.clear();
    dscene->tri_verts.clear();
    dscene->attributes_map.clear();
    dscene->attributes_float.clear();
    dscene->attributes_float3.clear();
}

void MeshManager::tag_update(Scene *scene)
{
    need_update = true;
    scene->object_manager->need_update = true;
}

CCL_NAMESPACE_END