From 735b31fc890de220c4c07d9b69a57186a0a214ef Mon Sep 17 00:00:00 2001
From: Yuval Tassa <tassa@google.com>
Date: Mon, 8 Dec 2025 09:26:02 -0800
Subject: [PATCH] Fix triangle lighting in native renderer.

PiperOrigin-RevId: 841796563
Change-Id: I778e0e02aa8b4033531d4fadc091610418ab909e
---
 src/render/render_gl3.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/render/render_gl3.c b/src/render/render_gl3.c
index 133e5d6a..4c931cc7 100644
--- a/src/render/render_gl3.c
+++ b/src/render/render_gl3.c
@@ -448,6 +448,7 @@ static void renderGeom(const mjvGeom* geom, int mode, const float* headpos,
   case mjGEOM_TRIANGLE:                       // triangle
     glDisable(GL_CULL_FACE);
     glBegin(GL_TRIANGLES);
+    glNormal3f(0, 0, 1);
     glVertex3f(0, 0, 0);
     glVertex3f(size[0], 0, 0);
     glVertex3f(0, size[1], 0);