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cgltf_node transform attributes are now store in double
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Some GLTF contain huge value in translation and reading these as float cause lost in precision. Google store big translation in their 'Photorealistic 3D Tiles' data
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@bcomb
bcomb committed Nov 23, 2023
1 parent fd3a618 commit c97fc13
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Showing 2 changed files with 102 additions and 49 deletions.
116 changes: 72 additions & 44 deletions cgltf.h
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Original file line number Diff line number Diff line change
Expand Up @@ -99,6 +99,7 @@ extern "C" {
typedef size_t cgltf_size;
typedef long long int cgltf_ssize;
typedef float cgltf_float;
typedef double cgltf_double;
typedef int cgltf_int;
typedef unsigned int cgltf_uint;
typedef int cgltf_bool;
Expand Down Expand Up @@ -659,10 +660,10 @@ struct cgltf_node {
cgltf_bool has_rotation;
cgltf_bool has_scale;
cgltf_bool has_matrix;
cgltf_float translation[3];
cgltf_float rotation[4];
cgltf_float scale[3];
cgltf_float matrix[16];
cgltf_double translation[3];
cgltf_double rotation[4];
cgltf_double scale[3];
cgltf_double matrix[16];
cgltf_extras extras;
cgltf_bool has_mesh_gpu_instancing;
cgltf_mesh_gpu_instancing mesh_gpu_instancing;
Expand Down Expand Up @@ -824,8 +825,8 @@ cgltf_result cgltf_validate(cgltf_data* data);

void cgltf_free(cgltf_data* data);

void cgltf_node_transform_local(const cgltf_node* node, cgltf_float* out_matrix);
void cgltf_node_transform_world(const cgltf_node* node, cgltf_float* out_matrix);
void cgltf_node_transform_local(const cgltf_node* node, cgltf_double* out_matrix);
void cgltf_node_transform_world(const cgltf_node* node, cgltf_double* out_matrix);

const uint8_t* cgltf_buffer_view_data(const cgltf_buffer_view* view);

Expand Down Expand Up @@ -2060,72 +2061,72 @@ void cgltf_free(cgltf_data* data)
data->memory.free_func(data->memory.user_data, data);
}

void cgltf_node_transform_local(const cgltf_node* node, cgltf_float* out_matrix)
void cgltf_node_transform_local(const cgltf_node* node, cgltf_double* out_matrix)
{
cgltf_float* lm = out_matrix;
cgltf_double* lm = out_matrix;

if (node->has_matrix)
{
memcpy(lm, node->matrix, sizeof(float) * 16);
memcpy(lm, node->matrix, sizeof(double) * 16);
}
else
{
float tx = node->translation[0];
float ty = node->translation[1];
float tz = node->translation[2];
double tx = node->translation[0];
double ty = node->translation[1];
double tz = node->translation[2];

float qx = node->rotation[0];
float qy = node->rotation[1];
float qz = node->rotation[2];
float qw = node->rotation[3];
double qx = node->rotation[0];
double qy = node->rotation[1];
double qz = node->rotation[2];
double qw = node->rotation[3];

float sx = node->scale[0];
float sy = node->scale[1];
float sz = node->scale[2];
double sx = node->scale[0];
double sy = node->scale[1];
double sz = node->scale[2];

lm[0] = (1 - 2 * qy*qy - 2 * qz*qz) * sx;
lm[1] = (2 * qx*qy + 2 * qz*qw) * sx;
lm[2] = (2 * qx*qz - 2 * qy*qw) * sx;
lm[3] = 0.f;
lm[3] = 0.;

lm[4] = (2 * qx*qy - 2 * qz*qw) * sy;
lm[5] = (1 - 2 * qx*qx - 2 * qz*qz) * sy;
lm[6] = (2 * qy*qz + 2 * qx*qw) * sy;
lm[7] = 0.f;
lm[7] = 0.;

lm[8] = (2 * qx*qz + 2 * qy*qw) * sz;
lm[9] = (2 * qy*qz - 2 * qx*qw) * sz;
lm[10] = (1 - 2 * qx*qx - 2 * qy*qy) * sz;
lm[11] = 0.f;
lm[11] = 0.;

lm[12] = tx;
lm[13] = ty;
lm[14] = tz;
lm[15] = 1.f;
lm[15] = 1.;
}
}

void cgltf_node_transform_world(const cgltf_node* node, cgltf_float* out_matrix)
void cgltf_node_transform_world(const cgltf_node* node, cgltf_double* out_matrix)
{
cgltf_float* lm = out_matrix;
cgltf_double* lm = out_matrix;
cgltf_node_transform_local(node, lm);

const cgltf_node* parent = node->parent;

while (parent)
{
float pm[16];
double pm[16];
cgltf_node_transform_local(parent, pm);

for (int i = 0; i < 4; ++i)
{
float l0 = lm[i * 4 + 0];
float l1 = lm[i * 4 + 1];
float l2 = lm[i * 4 + 2];
double l0 = lm[i * 4 + 0];
double l1 = lm[i * 4 + 1];
double l2 = lm[i * 4 + 2];

float r0 = l0 * pm[0] + l1 * pm[4] + l2 * pm[8];
float r1 = l0 * pm[1] + l1 * pm[5] + l2 * pm[9];
float r2 = l0 * pm[2] + l1 * pm[6] + l2 * pm[10];
double r0 = l0 * pm[0] + l1 * pm[4] + l2 * pm[8];
double r1 = l0 * pm[1] + l1 * pm[5] + l2 * pm[9];
double r2 = l0 * pm[2] + l1 * pm[6] + l2 * pm[10];

lm[i * 4 + 0] = r0;
lm[i * 4 + 1] = r1;
Expand Down Expand Up @@ -2641,6 +2642,16 @@ static cgltf_float cgltf_json_to_float(jsmntok_t const* tok, const uint8_t* json
return (cgltf_float)CGLTF_ATOF(tmp);
}

static cgltf_double cgltf_json_to_double(jsmntok_t const* tok, const uint8_t* json_chunk)
{
CGLTF_CHECK_TOKTYPE(*tok, JSMN_PRIMITIVE);
char tmp[128];
int size = (size_t)(tok->end - tok->start) < sizeof(tmp) ? (int)(tok->end - tok->start) : (int)(sizeof(tmp) - 1);
strncpy(tmp, (const char*)json_chunk + tok->start, size);
tmp[size] = 0;
return (cgltf_double)CGLTF_ATOF(tmp);
}

static cgltf_bool cgltf_json_to_bool(jsmntok_t const* tok, const uint8_t* json_chunk)
{
int size = (int)(tok->end - tok->start);
Expand Down Expand Up @@ -2702,6 +2713,23 @@ static int cgltf_parse_json_float_array(jsmntok_t const* tokens, int i, const ui
return i;
}

static int cgltf_parse_json_double_array(jsmntok_t const* tokens, int i, const uint8_t* json_chunk, double* out_array, int size)
{
CGLTF_CHECK_TOKTYPE(tokens[i], JSMN_ARRAY);
if (tokens[i].size != size)
{
return CGLTF_ERROR_JSON;
}
++i;
for (int j = 0; j < size; ++j)
{
CGLTF_CHECK_TOKTYPE(tokens[i], JSMN_PRIMITIVE);
out_array[j] = cgltf_json_to_double(tokens + i, json_chunk);
++i;
}
return i;
}

static int cgltf_parse_json_string(cgltf_options* options, jsmntok_t const* tokens, int i, const uint8_t* json_chunk, char** out_string)
{
CGLTF_CHECK_TOKTYPE(tokens[i], JSMN_STRING);
Expand Down Expand Up @@ -5439,14 +5467,14 @@ static int cgltf_parse_json_node(cgltf_options* options, jsmntok_t const* tokens
{
CGLTF_CHECK_TOKTYPE(tokens[i], JSMN_OBJECT);

out_node->rotation[3] = 1.0f;
out_node->scale[0] = 1.0f;
out_node->scale[1] = 1.0f;
out_node->scale[2] = 1.0f;
out_node->matrix[0] = 1.0f;
out_node->matrix[5] = 1.0f;
out_node->matrix[10] = 1.0f;
out_node->matrix[15] = 1.0f;
out_node->rotation[3] = 1.0;
out_node->scale[0] = 1.0;
out_node->scale[1] = 1.0;
out_node->scale[2] = 1.0;
out_node->matrix[0] = 1.0;
out_node->matrix[5] = 1.0;
out_node->matrix[10] = 1.0;
out_node->matrix[15] = 1.0;

int size = tokens[i].size;
++i;
Expand Down Expand Up @@ -5497,22 +5525,22 @@ static int cgltf_parse_json_node(cgltf_options* options, jsmntok_t const* tokens
else if (cgltf_json_strcmp(tokens+i, json_chunk, "translation") == 0)
{
out_node->has_translation = 1;
i = cgltf_parse_json_float_array(tokens, i + 1, json_chunk, out_node->translation, 3);
i = cgltf_parse_json_double_array(tokens, i + 1, json_chunk, out_node->translation, 3);
}
else if (cgltf_json_strcmp(tokens+i, json_chunk, "rotation") == 0)
{
out_node->has_rotation = 1;
i = cgltf_parse_json_float_array(tokens, i + 1, json_chunk, out_node->rotation, 4);
i = cgltf_parse_json_double_array(tokens, i + 1, json_chunk, out_node->rotation, 4);
}
else if (cgltf_json_strcmp(tokens+i, json_chunk, "scale") == 0)
{
out_node->has_scale = 1;
i = cgltf_parse_json_float_array(tokens, i + 1, json_chunk, out_node->scale, 3);
i = cgltf_parse_json_double_array(tokens, i + 1, json_chunk, out_node->scale, 3);
}
else if (cgltf_json_strcmp(tokens+i, json_chunk, "matrix") == 0)
{
out_node->has_matrix = 1;
i = cgltf_parse_json_float_array(tokens, i + 1, json_chunk, out_node->matrix, 16);
i = cgltf_parse_json_double_array(tokens, i + 1, json_chunk, out_node->matrix, 16);
}
else if (cgltf_json_strcmp(tokens + i, json_chunk, "weights") == 0)
{
Expand Down
35 changes: 30 additions & 5 deletions cgltf_write.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,6 +111,12 @@ typedef struct {
#define CGLTF_DECIMAL_DIG 9
#endif

#ifdef DBL_DECIMAL_DIG
#define CGLTF_DBL_DECIMAL_DIG (DBL_DECIMAL_DIG)
#else
#define CGLTF_DBL_DECIMAL_DIG 17
#endif

#define CGLTF_SPRINTF(...) { \
assert(context->cursor || (!context->cursor && context->remaining == 0)); \
context->tmp = snprintf ( context->cursor, context->remaining, __VA_ARGS__ ); \
Expand Down Expand Up @@ -333,6 +339,25 @@ static void cgltf_write_floatarrayprop(cgltf_write_context* context, const char*
context->needs_comma = 1;
}

static void cgltf_write_doublearrayprop(cgltf_write_context* context, const char* label, const cgltf_double* vals, cgltf_size dim)
{
cgltf_write_indent(context);
CGLTF_SPRINTF("\"%s\": [", label);
for (cgltf_size i = 0; i < dim; ++i)
{
if (i != 0)
{
CGLTF_SPRINTF(", %.*g", CGLTF_DBL_DECIMAL_DIG, vals[i]);
}
else
{
CGLTF_SPRINTF("%.*g", CGLTF_DBL_DECIMAL_DIG, vals[i]);
}
}
CGLTF_SPRINTF("]");
context->needs_comma = 1;
}

static bool cgltf_check_floatarray(const float* vals, int dim, float val) {
while (dim--)
{
Expand Down Expand Up @@ -950,20 +975,20 @@ static void cgltf_write_node(cgltf_write_context* context, const cgltf_node* nod
CGLTF_WRITE_IDXPROP("mesh", node->mesh, context->data->meshes);
cgltf_write_strprop(context, "name", node->name);
if (node->has_matrix)
{
cgltf_write_floatarrayprop(context, "matrix", node->matrix, 16);
{
cgltf_write_doublearrayprop(context, "matrix", node->matrix, 16);
}
if (node->has_translation)
{
cgltf_write_floatarrayprop(context, "translation", node->translation, 3);
cgltf_write_doublearrayprop(context, "translation", node->translation, 3);
}
if (node->has_rotation)
{
cgltf_write_floatarrayprop(context, "rotation", node->rotation, 4);
cgltf_write_doublearrayprop(context, "rotation", node->rotation, 4);
}
if (node->has_scale)
{
cgltf_write_floatarrayprop(context, "scale", node->scale, 3);
cgltf_write_doublearrayprop(context, "scale", node->scale, 3);
}
if (node->skin)
{
Expand Down

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