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authorMorris Tabor <80684659+mortarroad@users.noreply.github.com>2021-03-25 17:33:33 +0100
committerMorris Tabor <80684659+mortarroad@users.noreply.github.com>2021-03-25 17:33:44 +0100
commit0fc8318f1a4c5fdfcfe9f40932397f3d38ffc2e8 (patch)
tree5a83b2a434bae2dcfd1ed084c041a3786ed740b7 /scene
parent8d11b6374ee5488d9c327e86e196427740cfe312 (diff)
Fix ParticlesMaterial spread
Diffstat (limited to 'scene')
-rw-r--r--scene/resources/particles_material.cpp17
1 files changed, 12 insertions, 5 deletions
diff --git a/scene/resources/particles_material.cpp b/scene/resources/particles_material.cpp
index a0f4bf9409..195ce070a7 100644
--- a/scene/resources/particles_material.cpp
+++ b/scene/resources/particles_material.cpp
@@ -340,14 +340,21 @@ void ParticlesMaterial::_update_shader() {
//initiate velocity spread in 3D
code += " float angle1_rad = rand_from_seed_m1_p1(alt_seed) * spread_rad;\n";
code += " float angle2_rad = rand_from_seed_m1_p1(alt_seed) * spread_rad * (1.0 - flatness);\n";
- code += " angle1_rad += direction.z != 0.0 ? atan(direction.x, direction.z) : sign(direction.x) * (pi / 2.0);\n";
- code += " angle2_rad += direction.z != 0.0 ? atan(direction.y, abs(direction.z)) : (direction.x != 0.0 ? atan(direction.y, abs(direction.x)) : sign(direction.y) * (pi / 2.0));\n";
code += " vec3 direction_xz = vec3(sin(angle1_rad), 0.0, cos(angle1_rad));\n";
code += " vec3 direction_yz = vec3(0.0, sin(angle2_rad), cos(angle2_rad));\n";
code += " direction_yz.z = direction_yz.z / max(0.0001,sqrt(abs(direction_yz.z))); // better uniform distribution\n";
- code += " vec3 vec_direction = vec3(direction_xz.x * direction_yz.z, direction_yz.y, direction_xz.z * direction_yz.z);\n";
- code += " vec_direction = normalize(vec_direction);\n";
- code += " VELOCITY = vec_direction * initial_linear_velocity * mix(1.0, rand_from_seed(alt_seed), initial_linear_velocity_random);\n";
+ code += " vec3 spread_direction = vec3(direction_xz.x * direction_yz.z, direction_yz.y, direction_xz.z * direction_yz.z);\n";
+ code += " vec3 direction_nrm = normalize(direction);\n";
+ code += " // rotate spread to direction\n";
+ code += " vec3 binormal = cross(vec3(0.0, 1.0, 0.0), direction_nrm);\n";
+ code += " if (length(binormal) < 0.0001) {\n";
+ code += " // direction is parallel to Y. Choose Z as the binormal.\n";
+ code += " binormal = vec3(0.0, 0.0, 1.0);\n";
+ code += " }\n";
+ code += " binormal = normalize(binormal);\n";
+ code += " vec3 normal = cross(binormal, direction_nrm);\n";
+ code += " spread_direction = binormal * spread_direction.x + normal * spread_direction.y + direction_nrm * spread_direction.z;\n";
+ code += " VELOCITY = spread_direction * initial_linear_velocity * mix(1.0, rand_from_seed(alt_seed), initial_linear_velocity_random);\n";
}
code += " }\n";