Merge pull request #5175 from sfjohnston/sfjohnston_mods

Bug fix and improvement to FBX camera field-of-view during import.
pull/5195/head
Kim Kulling 2023-07-23 21:31:39 +02:00 committed by GitHub
commit 60989a598e
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2 changed files with 26 additions and 5 deletions

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@ -93,6 +93,8 @@ FBXConverter::FBXConverter(aiScene *out, const Document &doc, bool removeEmptyBo
mSceneOut(out),
doc(doc),
mRemoveEmptyBones(removeEmptyBones) {
// animations need to be converted first since this will
// populate the node_anim_chain_bits map, which is needed
// to determine which nodes need to be generated.
@ -427,12 +429,26 @@ void FBXConverter::ConvertCamera(const Camera &cam, const std::string &orig_name
out_camera->mLookAt = aiVector3D(1.0f, 0.0f, 0.0f);
out_camera->mUp = aiVector3D(0.0f, 1.0f, 0.0f);
out_camera->mHorizontalFOV = AI_DEG_TO_RAD(cam.FieldOfView());
// NOTE: Some software (maya) does not put FieldOfView in FBX, so we compute
// mHorizontalFOV from FocalLength and FilmWidth with unit conversion.
out_camera->mClipPlaneNear = cam.NearPlane();
out_camera->mClipPlaneFar = cam.FarPlane();
// TODO: This is not a complete solution for how FBX cameras can be stored.
// TODO: Incorporate non-square pixel aspect ratio.
// TODO: FBX aperture mode might be storing vertical FOV in need of conversion with aspect ratio.
float fov_deg = cam.FieldOfView();
// If FOV not specified in file, compute using FilmWidth and FocalLength.
if (fov_deg == kFovUnknown) {
float film_width_inches = cam.FilmWidth();
float focal_length_mm = cam.FocalLength();
ASSIMP_LOG_VERBOSE_DEBUG("FBX FOV unspecified. Computing from FilmWidth (", film_width_inches, "inches) and FocalLength (", focal_length_mm, "mm).");
double half_fov_rad = std::atan2(film_width_inches * 25.4 * 0.5, focal_length_mm);
out_camera->mHorizontalFOV = half_fov_rad;
} else {
// FBX fov is full-view degrees. We want half-view radians.
out_camera->mHorizontalFOV = AI_DEG_TO_RAD(fov_deg) * 0.5;
}
out_camera->mHorizontalFOV = AI_DEG_TO_RAD(cam.FieldOfView());
out_camera->mClipPlaneNear = cam.NearPlane();
out_camera->mClipPlaneFar = cam.FarPlane();
}

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@ -55,9 +55,14 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#define _AI_CONCAT(a,b) a ## b
#define AI_CONCAT(a,b) _AI_CONCAT(a,b)
namespace Assimp {
namespace FBX {
// Use an 'illegal' default FOV value to detect if the FBX camera has set the FOV.
static const float kFovUnknown = -1.0f;
class Parser;
class Object;
struct ImportSettings;
@ -247,7 +252,7 @@ public:
fbx_simple_property(FilmAspectRatio, float, 1.0f)
fbx_simple_property(ApertureMode, int, 0)
fbx_simple_property(FieldOfView, float, 1.0f)
fbx_simple_property(FieldOfView, float, kFovUnknown)
fbx_simple_property(FocalLength, float, 1.0f)
};