unbreak ground shadows

Author: nmwsharp

include/polyscope/view.h

@@ -77,6 +77,11 @@ extern const float defaultNearClipRatio;
 extern const float defaultFarClipRatio;
 extern const float defaultFov;
 
+// Internal details
+extern bool overrideClipPlanes; // used for temporary state changes in render passes, internal use only!
+extern float overrideNearClipRelative;
+extern float overrideFarClipRelative;
+
 // === View methods
 
 // == Get/Set the current camera view in the user's window

src/render/ground_plane.cpp

@@ -364,6 +364,9 @@ void GroundPlane::draw(bool isRedraw) {
     projMat[iP][iP] = 0.;
     projMat[3][iP] = groundHeight;
     view::viewMat = view::viewMat * projMat;
+    view::overrideClipPlanes = true; // set the clip planes manually
+    view::overrideNearClipRelative = view::defaultNearClipRatio;
+    view::overrideFarClipRelative = view::defaultFarClipRatio;
 
     // Draw everything
     render::engine->setDepthMode(DepthMode::Less);
@@ -396,6 +399,7 @@ void GroundPlane::draw(bool isRedraw) {
 
     // Restore original view matrix
     view::viewMat = origViewMat;
+    view::overrideClipPlanes = false;
   }
 
   render::engine->bindSceneBuffer();

src/view.cpp

@@ -54,6 +54,12 @@ const float defaultFov = 45.;
 const float minFov = 5.;   // for UI
 const float maxFov = 160.; // for UI
 
+// Internal details
+bool overrideClipPlanes =
+    false; // used only for temporary state changes in render passes, so we do not track in context
+float overrideNearClipRelative = defaultNearClipRatio;
+float overrideFarClipRelative = defaultFarClipRatio;
+
 // Small helpers
 
 namespace { // anonymous helpers
@@ -740,7 +746,12 @@ glm::mat4 getCameraPerspectiveMatrix() {
 
   // Set the clip plane
   float absNearClip, absFarClip;
-  std::tie(absNearClip, absFarClip) = computeClipPlanes();
+  if (overrideClipPlanes) {
+    absNearClip = overrideNearClipRelative * state::lengthScale;
+    absFarClip = overrideFarClipRelative * state::lengthScale;
+  } else {
+    std::tie(absNearClip, absFarClip) = computeClipPlanes();
+  }
 
   float fovRad = glm::radians(fov);
   float aspectRatio = (float)bufferWidth / bufferHeight;