Add flag for depth rendering.

PiperOrigin-RevId: 846203691
Change-Id: I5ec494446bcfc1f7c81536a87dd24f9967973563

doc/changelog.rst

@@ -12,6 +12,7 @@ General
   - The type of the ``sig`` (signature) argument of :ref:`mj_stateSize` and related functions has been changed from
     ``unsigned int`` to ``int``. Before this change, invalid negative arguments passed to this function would result in
     a silent implicit cast, now negativity will trigger an error.
+  - Added a :ref:`depth<mjtRndFlag>` rendering flag
 
 MJX
 ^^^

doc/includes/references.h

@@ -2829,6 +2829,7 @@ typedef enum mjtRndFlag_ {        // flags enabling rendering effects
   mjRND_SKYBOX,                   // skybox
   mjRND_FOG,                      // fog
   mjRND_HAZE,                     // haze
+  mjRND_DEPTH,                    // depth
   mjRND_SEGMENT,                  // segmentation with random color
   mjRND_IDCOLOR,                  // segmentation with segid+1 color
   mjRND_CULL_FACE,                // cull backward faces

include/mujoco/mjvisualize.h

@@ -146,6 +146,7 @@ typedef enum mjtRndFlag_ {        // flags enabling rendering effects
   mjRND_SKYBOX,                   // skybox
   mjRND_FOG,                      // fog
   mjRND_HAZE,                     // haze
+  mjRND_DEPTH,                    // depth
   mjRND_SEGMENT,                  // segmentation with random color
   mjRND_IDCOLOR,                  // segmentation with segid+1 color
   mjRND_CULL_FACE,                // cull backward faces

python/mujoco/introspect/enums.py

@@ -814,10 +814,11 @@ ENUMS: Mapping[str, EnumDecl] = dict([
              ('mjRND_SKYBOX', 4),
              ('mjRND_FOG', 5),
              ('mjRND_HAZE', 6),
-             ('mjRND_SEGMENT', 7),
-             ('mjRND_IDCOLOR', 8),
-             ('mjRND_CULL_FACE', 9),
-             ('mjNRNDFLAG', 10),
+             ('mjRND_DEPTH', 7),
+             ('mjRND_SEGMENT', 8),
+             ('mjRND_IDCOLOR', 9),
+             ('mjRND_CULL_FACE', 10),
+             ('mjNRNDFLAG', 11),
          ]),
      )),
     ('mjtStereo',

python/mujoco/introspect/structs.py

@@ -10169,7 +10169,7 @@ STRUCTS: Mapping[str, StructDecl] = dict([
                  name='flags',
                  type=ArrayType(
                      inner_type=ValueType(name='mjtByte'),
-                     extents=(10,),
+                     extents=(11,),
                  ),
                  doc='rendering flags (indexed by mjtRndFlag)',
              ),

src/engine/engine_vis_init.c

@@ -111,6 +111,7 @@ const char* mjRNDSTRING[mjNRNDFLAG][3] = {
   {"Skybox",      "1", "K"},
   {"Fog",         "0", "G"},
   {"Haze",        "1", "/"},
+  {"Depth",       "0", ""},
   {"Segment",     "0", ","},
   {"Id Color",    "0", ""},
   {"Cull Face",   "1", ""}

src/experimental/filament/filament/filament_context.cc

@@ -154,9 +154,13 @@ void FilamentContext::Render(const mjrRect& viewport, const mjvScene* scene,
     render_gui_ = gui_view_->PrepareRenderable();
   }
 
-  last_render_mode_ = scene->flags[mjRND_SEGMENT]
-                                 ? SceneView::DrawMode::kSegmentation
-                                 : SceneView::DrawMode::kNormal;
+  last_render_mode_ = SceneView::DrawMode::kNormal;
+  if (scene->flags[mjRND_SEGMENT]) {
+    last_render_mode_ = SceneView::DrawMode::kSegmentation;
+  } else if (scene->flags[mjRND_DEPTH]) {
+    last_render_mode_ = SceneView::DrawMode::kDepth;
+  }
+
   // Render the frame if we're not rendering to a texture.
   if (!render_to_texture_) {
     filament::View* view = scene_view_->PrepareRenderView(last_render_mode_);

src/render/render_gl3.c

@@ -1019,7 +1019,7 @@ void mjr_render(mjrRect viewport, mjvScene* scn, const mjrContext* con) {
     //---------------------------------- reflection rendering
 
     // plane and box reflection rendering
-    if (scn->flags[mjRND_REFLECTION]) {
+    if (scn->flags[mjRND_REFLECTION] && !scn->flags[mjRND_DEPTH]) {
       for (int i=0; i < ngeom; i++) {
         // get geom pointer
         thisgeom = scn->geoms + i;
@@ -1481,6 +1481,54 @@ void mjr_render(mjrRect viewport, mjvScene* scn, const mjrContext* con) {
     glDisable(GL_SCISSOR_TEST);
   }
 
+  if (scn->flags[mjRND_DEPTH]) {
+    glPushAttrib(GL_ENABLE_BIT | GL_TRANSFORM_BIT | GL_TEXTURE_BIT |
+                 GL_LIGHTING_BIT | GL_POLYGON_BIT);
+
+    glMatrixMode(GL_PROJECTION);
+    glPushMatrix();
+    glLoadIdentity();
+    glOrtho(0, 1, 0, 1, -1, 1);
+    glMatrixMode(GL_MODELVIEW);
+    glPushMatrix();
+    glLoadIdentity();
+
+    glDisable(GL_LIGHTING);
+    glDisable(GL_DEPTH_TEST);
+    glDisable(GL_CULL_FACE);
+    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+
+    void* depth_buf = mju_malloc(sizeof(float) * viewport.width * viewport.height);
+    glReadPixels(0, 0, viewport.width, viewport.height, GL_DEPTH_COMPONENT, GL_FLOAT, depth_buf);
+
+    GLuint depth_tex;
+    glEnable(GL_TEXTURE_2D);
+    glGenTextures(1, &depth_tex);
+    glBindTexture(GL_TEXTURE_2D, depth_tex);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, viewport.width, viewport.height,
+                 0, GL_LUMINANCE, GL_FLOAT, depth_buf);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+
+    glColor4f(1, 1, 1, 1);
+    glBegin(GL_QUADS);
+    glTexCoord2f(0, 0); glVertex2f(0, 0);
+    glTexCoord2f(1, 0); glVertex2f(1, 0);
+    glTexCoord2f(1, 1); glVertex2f(1, 1);
+    glTexCoord2f(0, 1); glVertex2f(0, 1);
+    glEnd();
+
+    glDeleteTextures(1, &depth_tex);
+    mju_free(depth_buf);
+
+    glMatrixMode(GL_PROJECTION);
+    glPopMatrix();
+    glMatrixMode(GL_MODELVIEW);
+    glPopMatrix();
+    glPopAttrib();
+  }
+
   // restore currentBuffer
   mjr_restoreBuffer(con);
 }

unity/Runtime/Bindings/MjBindings.cs

@@ -678,10 +678,11 @@ public enum mjtRndFlag : int{
   mjRND_SKYBOX = 4,
   mjRND_FOG = 5,
   mjRND_HAZE = 6,
-  mjRND_SEGMENT = 7,
-  mjRND_IDCOLOR = 8,
-  mjRND_CULL_FACE = 9,
-  mjNRNDFLAG = 10,
+  mjRND_DEPTH = 7,
+  mjRND_SEGMENT = 8,
+  mjRND_IDCOLOR = 9,
+  mjRND_CULL_FACE = 10,
+  mjNRNDFLAG = 11,
 }
 public enum mjtStereo : int{
   mjSTEREO_NONE = 0,
@@ -6315,7 +6316,7 @@ public unsafe struct mjvScene_ {
   public fixed float rotate[4];
   public float scale;
   public int stereo;
-  public fixed byte flags[10];
+  public fixed byte flags[11];
   public int framewidth;
   public fixed float framergb[3];
   public int status;

wasm/codegen/generated/bindings.cc

@@ -7523,7 +7523,7 @@ struct MjvScene {
   // skinvertadr field is handled manually in template file struct declaration
   // skinvertnum field is handled manually in template file struct declaration
   emscripten::val flags() const {
-    return emscripten::val(emscripten::typed_memory_view(10, ptr_->flags));
+    return emscripten::val(emscripten::typed_memory_view(11, ptr_->flags));
   }
   emscripten::val framergb() const {
     return emscripten::val(emscripten::typed_memory_view(3, ptr_->framergb));
@@ -10511,6 +10511,7 @@ EMSCRIPTEN_BINDINGS(mujoco_bindings) {
     .value("mjRND_SKYBOX", mjRND_SKYBOX)
     .value("mjRND_FOG", mjRND_FOG)
     .value("mjRND_HAZE", mjRND_HAZE)
+    .value("mjRND_DEPTH", mjRND_DEPTH)
     .value("mjRND_SEGMENT", mjRND_SEGMENT)
     .value("mjRND_IDCOLOR", mjRND_IDCOLOR)
     .value("mjRND_CULL_FACE", mjRND_CULL_FACE)

wasm/tests/bindings_test.ts

@@ -692,8 +692,8 @@ describe('MuJoCo WASM Bindings', () => {
     expect(mujoco.get_mjRNDSTRING()).toEqual([
       ['Shadow', '1', 'S'], ['Wireframe', '0', 'W'], ['Reflection', '1', 'R'],
       ['Additive', '0', 'L'], ['Skybox', '1', 'K'], ['Fog', '0', 'G'],
-      ['Haze', '1', '/'], ['Segment', '0', ','], ['Id Color', '0', ''],
-      ['Cull Face', '1', '']
+      ['Haze', '1', '/'], ['Depth', '0', ''], ['Segment', '0', ','],
+      ['Id Color', '0', ''], ['Cull Face', '1', '']
     ]);
     expect(mujoco.get_mjFRAMESTRING().length)
         .toEqual(mujoco.mjtFrame.mjNFRAME.value);