diff --git a/scene/resources/particle_process_material.cpp b/scene/resources/particle_process_material.cpp index ed87468db6b5..9ceddbc7b1b9 100644 --- a/scene/resources/particle_process_material.cpp +++ b/scene/resources/particle_process_material.cpp @@ -850,6 +850,27 @@ void ParticleProcessMaterial::_update_shader() { code += " }\n"; code += " if (RESTART_VELOCITY) {\n"; code += " VELOCITY = get_random_direction_from_spread(alt_seed, spread) * dynamic_params.initial_velocity_multiplier;\n"; + if (emission_shape == EMISSION_SHAPE_DIRECTED_POINTS) { + code += " int point = min(emission_texture_point_count - 1, int(rand_from_seed(alt_seed) * float(emission_texture_point_count)));\n"; + code += " ivec2 emission_tex_size = textureSize(emission_texture_points, 0);\n"; + code += " ivec2 emission_tex_ofs = ivec2(point % emission_tex_size.x, point / emission_tex_size.x);\n"; + if (particle_flags[PARTICLE_FLAG_DISABLE_Z]) { + code += " {\n"; + code += " mat2 rotm;"; + code += " rotm[0] = texelFetch(emission_texture_normal, emission_tex_ofs, 0).xy;\n"; + code += " rotm[1] = rotm[0].yx * vec2(1.0, -1.0);\n"; + code += " VELOCITY.xy = rotm * VELOCITY.xy;\n"; + code += " }\n"; + } else { + code += " {\n"; + code += " vec3 normal = texelFetch(emission_texture_normal, emission_tex_ofs, 0).xyz;\n"; + code += " vec3 v0 = abs(normal.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 1.0, 0.0);\n"; + code += " vec3 tangent = normalize(cross(v0, normal));\n"; + code += " vec3 bitangent = normalize(cross(tangent, normal));\n"; + code += " VELOCITY = mat3(tangent, bitangent, normal) * VELOCITY;\n"; + code += " }\n"; + } + } code += " }\n"; code += " process_display_param(params, 0.);\n"; code += "// process_dynamic_parameters(dynamic_params, 0., alt_seed, TRANSFORM, EMISSION_TRANSFORM, DELTA);\n"; @@ -939,7 +960,9 @@ void ParticleProcessMaterial::_update_shader() { code += " if (physics_params.damping > 0.0) {\n"; if (!particle_flags[PARTICLE_FLAG_DAMPING_AS_FRICTION]) { code += " float v = length(VELOCITY);\n"; - code += " v -= physics_params.damping * DELTA;\n"; + code += " // Realistic friction formula. We assume the mass of a particle to be 0.05kg.\n"; + code += " float damp = v * v * physics_params.damping * 0.05 * DELTA;\n"; + code += " v -= damp;\n"; code += " if (v < 0.0) {\n"; code += " VELOCITY = vec3(0.0);\n"; code += " } else {\n";