Add maxhullvert.

PiperOrigin-RevId: 641092710
Change-Id: Ib4fa828a9c82531614f0a67de9990340dbb25406

src/user/user_api.h

@@ -446,6 +446,7 @@ typedef struct mjsMesh_ {          // mesh specification
   double refquat[4];               // reference orientation
   double scale[3];                 // rescale mesh
   mjtByte smoothnormal;            // do not exclude large-angle faces from normals
+  int maxhullvert;                 // maximum vertex count for the convex hull
   mjFloatVec* uservert;            // user vertex data
   mjFloatVec* usernormal;          // user normal data
   mjFloatVec* usertexcoord;        // user texcoord data

src/user/user_init.c

@@ -243,6 +243,7 @@ void mjs_defaultMesh(mjsMesh* mesh) {
   memset(mesh, 0, sizeof(mjsMesh));
   mesh->refquat[0] = 1;
   mesh->scale[0] = mesh->scale[1] = mesh->scale[2] = 1;
+  mesh->maxhullvert = -1;
 }
 
 

src/user/user_mesh.cc

@@ -50,8 +50,8 @@
 
 #include <mujoco/mjmacro.h>
 #include <mujoco/mjmodel.h>
-#include <mujoco/mjtnum.h>
 #include <mujoco/mjplugin.h>
+#include <mujoco/mjtnum.h>
 #include "engine/engine_crossplatform.h"
 #include "engine/engine_io.h"
 #include "engine/engine_plugin.h"
@@ -135,6 +135,7 @@ mjCMesh::mjCMesh(mjCModel* _model, mjCDef* _def) {
   center_ = NULL;
   graph_ = NULL;
   needhull_ = false;
+  maxhullvert_ = -1;
   invalidorientation_.first = -1;
   invalidorientation_.second = -1;
   validarea_ = true;
@@ -223,6 +224,7 @@ void mjCMesh::CopyFromSpec() {
   facetexcoord_ = spec_facetexcoord_;
   file = &file_;
   content_type = &content_type_;
+  maxhullvert_ = spec.maxhullvert;
   uservert = &vert_;
   usernormal = &normal_;
   userface = &face_;
@@ -1548,12 +1550,17 @@ double& mjCMesh::GetVolumeRef(mjtGeomInertia type) {
 
 
 // make graph describing convex hull
-void mjCMesh::MakeGraph(void) {
+void mjCMesh::MakeGraph() {
   int adr, ok, curlong, totlong, exitcode;
   double* data;
   facetT* facet, **facetp;
   vertexT* vertex, *vertex1, **vertex1p;
-  char qhopt[10] = "qhull Qt";
+
+  std::string qhopt = "qhull Qt";
+  if (maxhullvert_ > -1) {
+    // qhull "TA" actually means "number of vertices added after the initial simplex"
+    qhopt += " TA" + std::to_string(maxhullvert_ - 4);
+  }
 
   // graph not needed for small meshes
   if (nvert() < 4) {
@@ -1585,7 +1592,7 @@ void mjCMesh::MakeGraph(void) {
   qh->NOerrexit = false;
   if (!exitcode) {
     // actual init
-    qh_initflags(qh, qhopt);
+    qh_initflags(qh, const_cast<char*>(qhopt.c_str()));
     qh_init_B(qh, data, nvert(), 3, False);
 
     // construct convex hull
@@ -1742,8 +1749,6 @@ void mjCMesh::MakeGraph(void) {
   }
 }
 
-
-
 // copy graph into face data
 void mjCMesh::CopyGraph(void) {
   // only if face data is missing

src/user/user_objects.h

@@ -778,6 +778,7 @@ class mjCMesh_ : public mjCBase {
   // size of mesh data to be copied into mjModel
   int szgraph_;                       // size of graph data in ints
   bool needhull_;                     // needs convex hull for collisions
+  int maxhullvert_;                   // max vertex count of convex hull
 
   mjCBoundingVolumeHierarchy tree_;   // bounding volume hierarchy
   std::vector<double> face_aabb_;     // bounding boxes of all faces

src/xml/xml_native_reader.cc

@@ -145,7 +145,7 @@ const char* MJCF[nMJCF][mjXATTRNUM] = {
 
     {"default", "R", "1", "class"},
     {"<"},
-        {"mesh", "?", "1", "scale"},
+        {"mesh", "?", "2", "scale", "maxhullvert"},
         {"material", "?", "10", "texture", "emission", "specular", "shininess",
             "reflectance", "metallic", "roughness", "rgba", "texrepeat", "texuniform"},
         {"joint", "?", "22", "type", "group", "pos", "axis", "springdamper",
@@ -221,8 +221,9 @@ const char* MJCF[nMJCF][mjXATTRNUM] = {
 
     {"asset", "*", "0"},
     {"<"},
-        {"mesh", "*", "12", "name", "class", "content_type", "file", "vertex", "normal",
-            "texcoord", "face", "refpos", "refquat", "scale", "smoothnormal"},
+        {"mesh", "*", "13", "name", "class", "content_type", "file", "vertex", "normal",
+            "texcoord", "face", "refpos", "refquat", "scale", "smoothnormal",
+            "maxhullvert"},
         {"<"},
           {"plugin", "*", "2", "plugin", "instance"},
           {"<"},
@@ -1391,6 +1392,11 @@ void mjXReader::OneMesh(XMLElement* elem, mjsMesh* pmesh) {
     pmesh->smoothnormal = (n==1);
   }
 
+  if (ReadAttrInt(elem, "maxhullvert", &n)) {
+    if (n != 0 && n < 4) throw mjXError(elem, "maxhullvert must be larger than 3");
+    pmesh->maxhullvert = n;
+  }
+
   // read user vertex data
   if (ReadAttrTxt(elem, "vertex", text)) {
     auto uservert = ReadAttrVec<float>(elem, "vertex");