From b49290be14d985d4cc60b0d110b8b8ad4d543ba0 Mon Sep 17 00:00:00 2001 From: Germano Date: Mon, 2 Apr 2018 12:21:09 -0300 Subject: Partial fix for T54491: Use a more accurate solution to calculate the frustum boundbox --- source/blender/draw/intern/draw_manager_exec.c | 106 +++++++++++++++++++++++-- 1 file changed, 98 insertions(+), 8 deletions(-) (limited to 'source/blender/draw') diff --git a/source/blender/draw/intern/draw_manager_exec.c b/source/blender/draw/intern/draw_manager_exec.c index 03db49bb4a7..07df8c28aeb 100644 --- a/source/blender/draw/intern/draw_manager_exec.c +++ b/source/blender/draw/intern/draw_manager_exec.c @@ -384,6 +384,103 @@ void DRW_state_clip_planes_reset(void) /** \name Clipping (DRW_clipping) * \{ */ +/* Extract the 8 corners (world space). + * Although less accurate, this solution can be simplified as follows: + * + * BKE_boundbox_init_from_minmax(&bbox, (const float[3]){-1.0f, -1.0f, -1.0f}, (const float[3]){1.0f, 1.0f, 1.0f}); + * for (int i = 0; i < 8; i++) {mul_project_m4_v3(viewprojinv, bbox.vec[i]);} + */ +static void draw_frustum_boundbox_calc(const float (*projmat)[4], const float (*viewinv)[4], BoundBox *r_bbox) +{ + float screenvecs[3][3], loc[3], near, far, w_half, h_half; + bool is_persp = projmat[3][3] == 0.0f; + copy_m3_m4(screenvecs, viewinv); + copy_v3_v3(loc, viewinv[3]); + + /* get the values of the minimum and maximum + * clipping planes distances and the height and + *width of the near plane divided by half. */ + if (is_persp) { + near = projmat[3][2] / (projmat[2][2] - 1.0f); + far = projmat[3][2] / (projmat[2][2] + 1.0f); + w_half = near / projmat[0][0]; + h_half = near / projmat[1][1]; + } + else { + near = (projmat[3][2] + 1.0f) / projmat[2][2]; + far = (projmat[3][2] - 1.0f) / projmat[2][2]; + w_half = 1.0f / projmat[0][0]; + h_half = 1.0f / projmat[1][1]; + } + + /* With vectors aligned to the screen, reconstruct + * the near plane from the dimensions obtained earlier. */ + float mid[3], hor[3], ver[3]; + mul_v3_v3fl(hor, screenvecs[0], w_half); + mul_v3_v3fl(ver, screenvecs[1], h_half); + madd_v3_v3v3fl(mid, loc, screenvecs[2], -near); + + /* The case below is for non-symmetric frustum. */ + if (is_persp) { + madd_v3_v3fl(mid, hor, projmat[2][0]); + madd_v3_v3fl(mid, ver, projmat[2][1]); + } + else { + madd_v3_v3fl(mid, hor, projmat[3][0]); + madd_v3_v3fl(mid, ver, projmat[3][1]); + } + + r_bbox->vec[0][0] = mid[0] - ver[0] - hor[0]; + r_bbox->vec[0][1] = mid[1] - ver[1] - hor[1]; + r_bbox->vec[0][2] = mid[2] - ver[2] - hor[2]; + + r_bbox->vec[3][0] = mid[0] + ver[0] - hor[0]; + r_bbox->vec[3][1] = mid[1] + ver[1] - hor[1]; + r_bbox->vec[3][2] = mid[2] + ver[2] - hor[2]; + + r_bbox->vec[7][0] = mid[0] + ver[0] + hor[0]; + r_bbox->vec[7][1] = mid[1] + ver[1] + hor[1]; + r_bbox->vec[7][2] = mid[2] + ver[2] + hor[2]; + + r_bbox->vec[4][0] = mid[0] - ver[0] + hor[0]; + r_bbox->vec[4][1] = mid[1] - ver[1] + hor[1]; + r_bbox->vec[4][2] = mid[2] - ver[2] + hor[2]; + + /* Get the coordinates of the far plane. */ + if (is_persp) { + float sca_far = far / near; + mid[0] = mid[0] + (mid[0] - loc[0]) * sca_far; + mid[1] = mid[1] + (mid[1] - loc[1]) * sca_far; + mid[2] = mid[2] + (mid[2] - loc[2]) * sca_far; + + mul_v3_fl(hor, sca_far); + mul_v3_fl(ver, sca_far); + } + else { + madd_v3_v3v3fl(mid, loc, screenvecs[2], -far); + + /* Non-symmetric frustum. */ + madd_v3_v3fl(mid, hor, projmat[3][0]); + madd_v3_v3fl(mid, ver, projmat[3][1]); + } + + r_bbox->vec[1][0] = mid[0] - ver[0] - hor[0]; + r_bbox->vec[1][1] = mid[1] - ver[1] - hor[1]; + r_bbox->vec[1][2] = mid[2] - ver[2] - hor[2]; + + r_bbox->vec[2][0] = mid[0] + ver[0] - hor[0]; + r_bbox->vec[2][1] = mid[1] + ver[1] - hor[1]; + r_bbox->vec[2][2] = mid[2] + ver[2] - hor[2]; + + r_bbox->vec[6][0] = mid[0] + ver[0] + hor[0]; + r_bbox->vec[6][1] = mid[1] + ver[1] + hor[1]; + r_bbox->vec[6][2] = mid[2] + ver[2] + hor[2]; + + r_bbox->vec[5][0] = mid[0] - ver[0] + hor[0]; + r_bbox->vec[5][1] = mid[1] - ver[1] + hor[1]; + r_bbox->vec[5][2] = mid[2] - ver[2] + hor[2]; +} + static void draw_clipping_setup_from_view(void) { if (DST.clipping.updated) @@ -396,14 +493,7 @@ static void draw_clipping_setup_from_view(void) /* Extract Clipping Planes */ BoundBox bbox; - BKE_boundbox_init_from_minmax(&bbox, (const float[3]){-1.0f, -1.0f, -1.0f}, (const float[3]){1.0f, 1.0f, 1.0f}); - - /* Extract the 8 corners (world space). */ - for (int i = 0; i < 8; i++) { - /* Use separate matrix mul for more precision. */ - mul_project_m4_v3(projinv, bbox.vec[i]); - mul_m4_v3(viewinv, bbox.vec[i]); - } + draw_frustum_boundbox_calc(projmat, viewinv, &bbox); /* Compute clip planes using the world space frustum corners. */ for (int p = 0; p < 6; p++) { -- cgit v1.2.3