blender_camera.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 "camera.h"
#include "scene.h"

#include "blender_sync.h"
#include "blender_util.h"

CCL_NAMESPACE_BEGIN

/* Blender Camera Intermediate: we first convert both the offline and 3d view
 * render camera to this, and from there convert to our native camera format. */

struct BlenderCamera {
    float nearclip;
    float farclip;

    bool ortho;
    float ortho_scale;

    float lens;

    float aperturesize;
    uint apertureblades;
    float aperturerotation;
    float focaldistance;

    float2 shift;
    float2 offset;
    float zoom;

    float2 pixelaspect;

    enum { AUTO, HORIZONTAL, VERTICAL } sensor_fit;
    float sensor_width;
    float sensor_height;

    Transform matrix;
};

static void blender_camera_init(BlenderCamera *bcam)
{
    memset(bcam, 0, sizeof(BlenderCamera));

    bcam->zoom = 1.0f;
    bcam->pixelaspect = make_float2(1.0f, 1.0f);
    bcam->sensor_width = 32.0f;
    bcam->sensor_height = 18.0f;
    bcam->sensor_fit = BlenderCamera::AUTO;
}

static float blender_camera_focal_distance(BL::Object b_ob, BL::Camera b_camera)
{
    BL::Object b_dof_object = b_camera.dof_object();

    if(!b_dof_object)
        return b_camera.dof_distance();
    
    /* for dof object, return distance along camera Z direction */
    Transform obmat = transform_clear_scale(get_transform(b_ob.matrix_world()));
    Transform dofmat = get_transform(b_dof_object.matrix_world());
    Transform mat = transform_inverse(obmat) * dofmat;

    return fabsf(transform_get_column(&mat, 3).z);
}

static void blender_camera_from_object(BlenderCamera *bcam, BL::Object b_ob)
{
    BL::ID b_ob_data = b_ob.data();

    if(b_ob_data.is_a(&RNA_Camera)) {
        BL::Camera b_camera(b_ob_data);
        PointerRNA ccamera = RNA_pointer_get(&b_camera.ptr, "cycles");

        bcam->nearclip = b_camera.clip_start();
        bcam->farclip = b_camera.clip_end();

        bcam->ortho = (b_camera.type() == BL::Camera::type_ORTHO);
        bcam->ortho_scale = b_camera.ortho_scale();

        bcam->lens = b_camera.lens();
        bcam->aperturesize = RNA_float_get(&ccamera, "aperture_size");
        bcam->apertureblades = RNA_int_get(&ccamera, "aperture_blades");
        bcam->aperturerotation = RNA_float_get(&ccamera, "aperture_rotation");
        bcam->focaldistance = blender_camera_focal_distance(b_ob, b_camera);

        bcam->shift.x = b_camera.shift_x();
        bcam->shift.y = b_camera.shift_y();

        bcam->sensor_width = b_camera.sensor_width();
        bcam->sensor_height = b_camera.sensor_height();

        if(b_camera.sensor_fit() == BL::Camera::sensor_fit_AUTO)
            bcam->sensor_fit = BlenderCamera::AUTO;
        else if(b_camera.sensor_fit() == BL::Camera::sensor_fit_HORIZONTAL)
            bcam->sensor_fit = BlenderCamera::HORIZONTAL;
        else
            bcam->sensor_fit = BlenderCamera::VERTICAL;
    }
    else {
        /* from lamp not implemented yet */
    }
}

static void blender_camera_sync(Camera *cam, BlenderCamera *bcam, int width, int height)
{
    /* copy camera to compare later */
    Camera prevcam = *cam;

    /* dimensions */
    float xratio = width*bcam->pixelaspect.x;
    float yratio = height*bcam->pixelaspect.y;

    /* compute x/y aspect and ratio */
    float aspectratio, xaspect, yaspect;

    /* sensor fitting */
    bool horizontal_fit;
    float sensor_size;

    if(bcam->sensor_fit == BlenderCamera::AUTO) {
        horizontal_fit = (xratio > yratio);
        sensor_size = bcam->sensor_width;
    }
    else if(bcam->sensor_fit == BlenderCamera::HORIZONTAL) {
        horizontal_fit = true;
        sensor_size = bcam->sensor_width;
    }
    else {
        horizontal_fit = false;
        sensor_size = bcam->sensor_height;
    }

    if(horizontal_fit) {
        aspectratio= xratio/yratio;
        xaspect= aspectratio;
        yaspect= 1.0f;
    }
    else {
        aspectratio= yratio/xratio;
        xaspect= 1.0f;
        yaspect= aspectratio;
    }

    /* modify aspect for orthographic scale */
    if(bcam->ortho) {
        xaspect = xaspect*bcam->ortho_scale/(aspectratio*2.0f);
        yaspect = yaspect*bcam->ortho_scale/(aspectratio*2.0f);
        aspectratio = bcam->ortho_scale/2.0f;
    }

    /* set viewplane */
    cam->left = -xaspect;
    cam->right = xaspect;
    cam->bottom = -yaspect;
    cam->top = yaspect;

    /* zoom for 3d camera view */
    cam->left *= bcam->zoom;
    cam->right *= bcam->zoom;
    cam->bottom *= bcam->zoom;
    cam->top *= bcam->zoom;

    /* modify viewplane with camera shift and 3d camera view offset */
    float dx = 2.0f*(aspectratio*bcam->shift.x + bcam->offset.x*xaspect*2.0f);
    float dy = 2.0f*(aspectratio*bcam->shift.y + bcam->offset.y*yaspect*2.0f);

    cam->left += dx;
    cam->right += dx;
    cam->bottom += dy;
    cam->top += dy;

    /* clipping distances */
    cam->nearclip = bcam->nearclip;
    cam->farclip = bcam->farclip;

    /* orthographic */
    cam->ortho = bcam->ortho;

    /* perspective */
    cam->fov = 2.0f*atan((0.5f*sensor_size)/bcam->lens/aspectratio);
    cam->focaldistance = bcam->focaldistance;
    cam->aperturesize = bcam->aperturesize;
    cam->blades = bcam->apertureblades;
    cam->bladesrotation = bcam->aperturerotation;

    /* transform, note the blender camera points along the negative z-axis */
    cam->matrix = bcam->matrix * transform_scale(1.0f, 1.0f, -1.0f);
    cam->matrix = transform_clear_scale(cam->matrix);

    /* set update flag */
    if(cam->modified(prevcam))
        cam->tag_update();
}

/* Sync Render Camera */

void BlenderSync::sync_camera(int width, int height)
{
    BlenderCamera bcam;
    blender_camera_init(&bcam);

    /* pixel aspect */
    BL::RenderSettings r = b_scene.render();

    bcam.pixelaspect.x = r.pixel_aspect_x();
    bcam.pixelaspect.y = r.pixel_aspect_y();

    /* camera object */
    BL::Object b_ob = b_scene.camera();

    if(b_ob) {
        blender_camera_from_object(&bcam, b_ob);
        bcam.matrix = get_transform(b_ob.matrix_world());
    }

    /* sync */
    Camera *cam = scene->camera;
    blender_camera_sync(cam, &bcam, width, height);
}

/* Sync 3D View Camera */

void BlenderSync::sync_view(BL::SpaceView3D b_v3d, BL::RegionView3D b_rv3d, int width, int height)
{
    BlenderCamera bcam;
    blender_camera_init(&bcam);

    /* 3d view parameters */
    bcam.nearclip = b_v3d.clip_start();
    bcam.farclip = b_v3d.clip_end();
    bcam.lens = b_v3d.lens();

    if(b_rv3d.view_perspective() == BL::RegionView3D::view_perspective_CAMERA) {
        /* camera view */
        BL::Object b_ob = b_scene.camera();

        if(b_ob) {
            blender_camera_from_object(&bcam, b_ob);

            /* magic zoom formula */
            bcam.zoom = (float)b_rv3d.view_camera_zoom();
            bcam.zoom = (1.41421f + bcam.zoom/50.0f);
            bcam.zoom *= bcam.zoom;
            bcam.zoom = 2.0f/bcam.zoom;

            /* offset */
            bcam.offset = get_float2(b_rv3d.view_camera_offset());
        }
    }
    else if(b_rv3d.view_perspective() == BL::RegionView3D::view_perspective_ORTHO) {
        /* orthographic view */
        bcam.farclip *= 0.5;
        bcam.nearclip = -bcam.farclip;

        bcam.ortho = true;
        bcam.ortho_scale = b_rv3d.view_distance();
    }

    bcam.zoom *= 2.0f;

    /* 3d view transform */
    bcam.matrix = transform_inverse(get_transform(b_rv3d.view_matrix()));

    /* sync */
    blender_camera_sync(scene->camera, &bcam, width, height);
}

BufferParams BlenderSync::get_buffer_params(BL::Scene b_scene, BL::RegionView3D b_rv3d, int width, int height)
{
    BufferParams params;

    params.full_width = width;
    params.full_height = height;

    /* border render */
    BL::RenderSettings r = b_scene.render();

    if(!b_rv3d && r.use_border()) {
        params.full_x = r.border_min_x()*width;
        params.full_y = r.border_min_y()*height;
        params.width = (int)(r.border_max_x()*width) - params.full_x;
        params.height = (int)(r.border_max_y()*height) - params.full_y;
    }
    else {
        params.width = width;
        params.height = height;
    }

    return params;
}

CCL_NAMESPACE_END