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Replaced SQUAD quat interpolation with cubic hermite to align with gltf 2.0 spec (#3920)

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Benji 2024-04-17 02:10:48 -04:00 • committed by GitHub
parent e42f9263b8
commit 4491ff0426
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2 changed files with 42 additions and 16 deletions
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30
src/raymath.h
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@ -956,7 +956,7 @@ RMAPI Vector3 Vector3Lerp(Vector3 v1, Vector3 v2, float amount)
}
// Calculate cubic hermite interpolation between two vectors and their tangents
// taken directly from: https://en.wikipedia.org/wiki/Cubic_Hermite_spline
// as described in the GLTF 2.0 specification: https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#interpolation-cubic
RMAPI Vector3 Vector3CubicHermite(Vector3 v1, Vector3 tangent1, Vector3 v2, Vector3 tangent2, float amount)
{
Vector3 result = { 0 };
@ -2213,15 +2213,29 @@ RMAPI Quaternion QuaternionSlerp(Quaternion q1, Quaternion q2, float amount)
return result;
}
// Calculate quaternion cubic spline interpolation using the SQUAD algorithm
// roughly adapted from the SQUAD algorithm presented here: https://roboop.sourceforge.io/htmldoc/robotse9.html
RMAPI Quaternion QuaternionCubicSpline(Quaternion q1, Quaternion tangent1, Quaternion q2, Quaternion tangent2, float amount)
// Calculate quaternion cubic spline interpolation using Cubic Hermite Spline algorithm
// as described in the GLTF 2.0 specification: https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#interpolation-cubic
RMAPI Quaternion QuaternionCubicHermiteSpline(Quaternion q1, Quaternion outTangent1, Quaternion q2, Quaternion inTangent2, float t)
{
Quaternion slerp1 = QuaternionSlerp(q1, q2, amount);
Quaternion slerp2 = QuaternionSlerp(tangent1, tangent2, amount);
float t = 2 * amount * (1 - amount);
float t2 = t * t;
float t3 = t2 * t;
float h00 = 2 * t3 - 3 * t2 + 1;
float h10 = t3 - 2 * t2 + t;
float h01 = -2 * t3 + 3 * t2;
float h11 = t3 - t2;
Quaternion p0 = QuaternionScale(q1, h00);
Quaternion m0 = QuaternionScale(outTangent1, h10);
Quaternion p1 = QuaternionScale(q2, h01);
Quaternion m1 = QuaternionScale(inTangent2, h11);
Quaternion result = { 0 };
result = QuaternionAdd(p0, m0);
result = QuaternionAdd(result, p1);
result = QuaternionAdd(result, m1);
result = QuaternionNormalize(result);
Quaternion result = QuaternionSlerp(slerp1, slerp2, t);
return result;
}

28
src/rmodels.c
View file

@ -5380,7 +5380,8 @@ static bool GetPoseAtTimeGLTF(cgltf_interpolation_type interpolationType, cgltf_
}
}
float t = (time - tstart)/fmax((tend - tstart), EPSILON);
float duration = fmax((tend - tstart), EPSILON);
float t = (time - tstart)/duration;
t = (t < 0.0f)? 0.0f : t;
t = (t > 1.0f)? 1.0f : t;
@ -5419,9 +5420,9 @@ static bool GetPoseAtTimeGLTF(cgltf_interpolation_type interpolationType, cgltf_
Vector3 v1 = {tmp[0], tmp[1], tmp[2]};
cgltf_accessor_read_float(output, 3*keyframe+2, tmp, 3);
Vector3 tangent1 = {tmp[0], tmp[1], tmp[2]};
cgltf_accessor_read_float(output, 3*(keyframe+1), tmp, 3);
Vector3 v2 = {tmp[0], tmp[1], tmp[2]};
cgltf_accessor_read_float(output, 3*(keyframe+1)+1, tmp, 3);
Vector3 v2 = {tmp[0], tmp[1], tmp[2]};
cgltf_accessor_read_float(output, 3*(keyframe+1), tmp, 3);
Vector3 tangent2 = {tmp[0], tmp[1], tmp[2]};
Vector3 *r = data;
@ -5462,14 +5463,25 @@ static bool GetPoseAtTimeGLTF(cgltf_interpolation_type interpolationType, cgltf_
cgltf_accessor_read_float(output, 3*keyframe+1, tmp, 4);
Vector4 v1 = {tmp[0], tmp[1], tmp[2], tmp[3]};
cgltf_accessor_read_float(output, 3*keyframe+2, tmp, 4);
Vector4 tangent1 = {tmp[0], tmp[1], tmp[2]};
cgltf_accessor_read_float(output, 3*(keyframe+1), tmp, 4);
Vector4 v2 = {tmp[0], tmp[1], tmp[2], tmp[3]};
Vector4 outTangent1 = {tmp[0], tmp[1], tmp[2]};
cgltf_accessor_read_float(output, 3*(keyframe+1)+1, tmp, 4);
Vector4 tangent2 = {tmp[0], tmp[1], tmp[2]};
Vector4 v2 = {tmp[0], tmp[1], tmp[2], tmp[3]};
cgltf_accessor_read_float(output, 3*(keyframe+1), tmp, 4);
Vector4 inTangent2 = {tmp[0], tmp[1], tmp[2]};
Vector4 *r = data;
*r = QuaternionCubicSpline(v1, tangent1, v2, tangent2, t);
v1 = QuaternionNormalize(v1);
v2 = QuaternionNormalize(v2);
if (Vector4DotProduct(v1, v2) < 0.0f)
{
v2 = Vector4Negate(v2);
}
outTangent1 = Vector4Scale(outTangent1, duration);
inTangent2 = Vector4Scale(inTangent2, duration);
*r = QuaternionCubicHermiteSpline(v1, outTangent1, v2, inTangent2, t);
} break;
}
}