From 100b1a06fd8f6a184a3e495adff3ff044b1ff4f2 Mon Sep 17 00:00:00 2001
From: Alessio Quaglino <quaglino@google.com>
Date: Sun, 3 Aug 2025 08:34:55 -0700
Subject: [PATCH] Decrease opacity of taxels with zero value.

This prevents the taxels from being occluded by the convex hull for meshes that do not provide face connectivity.

PiperOrigin-RevId: 790420616
Change-Id: I543fd7b52e4625d921b6b5b5b77b4720020df42a
---
 src/engine/engine_vis_visualize.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/engine/engine_vis_visualize.c b/src/engine/engine_vis_visualize.c
index 02491e44..b8a479f2 100644
--- a/src/engine/engine_vis_visualize.c
+++ b/src/engine/engine_vis_visualize.c
@@ -910,6 +910,10 @@ void mjv_addGeoms(const mjModel* m, mjData* d, const mjvOption* vopt,
               }
             }
 
+            if (rgba[0]==0 && rgba[1]==0 && rgba[2]==0) {
+              rgba[3] = .1;
+            }
+
             // draw triangles, one per side
             START
             makeTriangle(thisgeom, pos[0], pos[1], pos[2], rgba);