Fix depth/stencil state for is3D drawables in layer groups without stencil tiles

platform/android/CHANGELOG.md

@@ -8,6 +8,7 @@
 
 ### 🐞 Bug fixes
 
+- Fix missing depth/stencil render-group state for 3D drawables in layer groups without stencil tiles (previously: Metal rendered without depth, OpenGL discarded all fragments).
 - fix(core): Update image descriptor sets when removing textures ([#4351](https://github.com/maplibre/maplibre-native/pull/4351)).
 - Fix surface snapshot timing ([#4339](https://github.com/maplibre/maplibre-native/pull/4339)).
 - core: Fix dynamic texture resource management ([#4337](https://github.com/maplibre/maplibre-native/pull/4337)).

platform/ios/CHANGELOG.md

@@ -5,6 +5,7 @@ MapLibre welcomes participation and contributions from everyone. Please read [`M
 ## 6.27.0
 
 - Implement ambient cache for PMTiles sources ([#4290](https://github.com/maplibre/maplibre-native/pull/4290)).
+- Fix missing depth/stencil render-group state for 3D drawables in layer groups without stencil tiles (previously: Metal rendered without depth, OpenGL discarded all fragments).
 
 ## 6.26.1
 

src/mbgl/gl/layer_group_gl.cpp

@@ -71,17 +71,19 @@ void TileLayerGroupGL::render(RenderOrchestrator&, PaintParameters& parameters)
         const auto debugGroupClip = parameters.encoder->createDebugGroup(label_clip.c_str());
 #endif
 
-        // If we're using stencil clipping, we need to handle 3D features separately
-        if (stencilTiles && !stencilTiles->empty()) {
-            visitDrawables([&](const gfx::Drawable& drawable) {
-                if (drawable.getEnabled() && drawable.getIs3D() && drawable.hasRenderPass(parameters.pass)) {
-                    features3d = true;
-                    if (drawable.getEnableStencil()) {
-                        stencil3d = true;
-                    }
+        // 3D features need the group-level stencil state: `DrawableGL::draw`
+        // intentionally skips stencil setup for is3D drawables. Detect them
+        // even without stencil tiles, otherwise is3D drawables (e.g. custom
+        // drawable geometry) inherit whatever stencil state the previous layer
+        // left bound and their fragments get discarded.
+        visitDrawables([&](const gfx::Drawable& drawable) {
+            if (drawable.getEnabled() && drawable.getIs3D() && drawable.hasRenderPass(parameters.pass)) {
+                features3d = true;
+                if (stencilTiles && !stencilTiles->empty() && drawable.getEnableStencil()) {
+                    stencil3d = true;
                 }
-            });
-        }
+            }
+        });
 
         // If we're doing 3D stenciling and have any features
         // to draw, set up the single-value stencil mask.

src/mbgl/mtl/tile_layer_group.cpp

@@ -54,17 +54,18 @@ void TileLayerGroup::render(RenderOrchestrator&, PaintParameters& parameters) {
     bool stencil3d = false;
     gfx::StencilMode stencilMode3d;
 
-    // If we're using stencil clipping, we need to handle 3D features separately
-    if (stencilTiles && !stencilTiles->empty()) {
-        visitDrawables([&](const gfx::Drawable& drawable) {
-            if (drawable.getEnabled() && drawable.getIs3D() && drawable.hasRenderPass(parameters.pass)) {
-                features3d = true;
-                if (drawable.getEnableStencil()) {
-                    stencil3d = true;
-                }
+    // 3D features need the group-level depth/stencil state: `Drawable::draw`
+    // intentionally skips depth-stencil setup for is3D drawables. Detect them
+    // even without stencil tiles, otherwise is3D drawables (e.g. custom
+    // drawable geometry) render with whatever state happens to be bound.
+    visitDrawables([&](const gfx::Drawable& drawable) {
+        if (drawable.getEnabled() && drawable.getIs3D() && drawable.hasRenderPass(parameters.pass)) {
+            features3d = true;
+            if (stencilTiles && !stencilTiles->empty() && drawable.getEnableStencil()) {
+                stencil3d = true;
             }
-        });
-    }
+        }
+    });
 
 #if !defined(NDEBUG)
     const auto debugGroupRender = parameters.encoder->createDebugGroup(getName() + "-render");