Improve polygon creation logic in compiler.

PiperOrigin-RevId: 875070301
Change-Id: I06e851f3450035fff68b99997406d6ea471ce3b8

test/engine/engine_collision_gjk_test.cc

@@ -1373,7 +1373,7 @@ TEST_F(MjGjkTest, BoxMesh) {
   std::vector<mjtNum> dir, pos;
   mjtNum dist;
   int ncons = Penetration(status, dist, dir, pos, model, data, g2, g1, 0, 1000);
-
+  EXPECT_EQ(model->nmeshpoly, 7);
   EXPECT_EQ(ncons, 4);
   mj_deleteData(data);
   mj_deleteModel(model);

test/fixture.cc

@@ -238,16 +238,12 @@ mjtNum CompareModel(const mjModel* m1, const mjModel* m2,
   MJMODEL_POINTERS_PREAMBLE(m1);
 
 // compare ints, exclude nbuffer because it hides the actual difference
-// TODO(kylebayes): re-enable poly comparisons.
-#define X(name)                                               \
-  if constexpr (std::string_view(#name) != "nbuffer" &&       \
-                std::string_view(#name) != "nmeshpolymap" &&  \
-                std::string_view(#name) != "nmeshpolyvert" && \
-                std::string_view(#name) != "nmeshpoly") {     \
-    if (m1->name != m2->name) {                               \
-      maxdif = std::abs((long)m1->name - (long)m2->name);     \
-      field = #name;                                          \
-    }                                                         \
+#define X(name)                                           \
+  if constexpr (std::string_view(#name) != "nbuffer") {   \
+    if (m1->name != m2->name) {                           \
+      maxdif = std::abs((long)m1->name - (long)m2->name); \
+      field = #name;                                      \
+    }                                                     \
   }
   MJMODEL_SIZES
 #undef X