diff --git a/doc/classes/BaseMaterial3D.xml b/doc/classes/BaseMaterial3D.xml
index d2425313f78..bf680aa88ce 100644
--- a/doc/classes/BaseMaterial3D.xml
+++ b/doc/classes/BaseMaterial3D.xml
@@ -398,6 +398,7 @@
 		</member>
 		<member name="uv1_triplanar_sharpness" type="float" setter="set_uv1_triplanar_blend_sharpness" getter="get_uv1_triplanar_blend_sharpness" default="1.0">
 			A lower number blends the texture more softly while a higher number blends the texture more sharply.
+			[b]Note:[/b] [member uv1_triplanar_sharpness] is clamped between [code]0.0[/code] and [code]150.0[/code] (inclusive) as values outside that range can look broken depending on the mesh.
 		</member>
 		<member name="uv1_world_triplanar" type="bool" setter="set_flag" getter="get_flag" default="false">
 			If [code]true[/code], triplanar mapping for [code]UV[/code] is calculated in world space rather than object local space. See also [member uv1_triplanar].
@@ -413,6 +414,7 @@
 		</member>
 		<member name="uv2_triplanar_sharpness" type="float" setter="set_uv2_triplanar_blend_sharpness" getter="get_uv2_triplanar_blend_sharpness" default="1.0">
 			A lower number blends the texture more softly while a higher number blends the texture more sharply.
+			[b]Note:[/b] [member uv2_triplanar_sharpness] is clamped between [code]0.0[/code] and [code]150.0[/code] (inclusive) as values outside that range can look broken depending on the mesh.
 		</member>
 		<member name="uv2_world_triplanar" type="bool" setter="set_flag" getter="get_flag" default="false">
 			If [code]true[/code], triplanar mapping for [code]UV2[/code] is calculated in world space rather than object local space. See also [member uv2_triplanar].
diff --git a/scene/resources/material.cpp b/scene/resources/material.cpp
index 78b6fd7945c..bd0e4701121 100644
--- a/scene/resources/material.cpp
+++ b/scene/resources/material.cpp
@@ -2052,8 +2052,9 @@ Vector3 BaseMaterial3D::get_uv1_offset() const {
 }
 
 void BaseMaterial3D::set_uv1_triplanar_blend_sharpness(float p_sharpness) {
-	uv1_triplanar_sharpness = p_sharpness;
-	RS::get_singleton()->material_set_param(_get_material(), shader_names->uv1_blend_sharpness, p_sharpness);
+	// Negative values or values higher than 150 can result in NaNs, leading to broken rendering.
+	uv1_triplanar_sharpness = CLAMP(p_sharpness, 0.0, 150.0);
+	RS::get_singleton()->material_set_param(_get_material(), shader_names->uv1_blend_sharpness, uv1_triplanar_sharpness);
 }
 
 float BaseMaterial3D::get_uv1_triplanar_blend_sharpness() const {
@@ -2079,8 +2080,9 @@ Vector3 BaseMaterial3D::get_uv2_offset() const {
 }
 
 void BaseMaterial3D::set_uv2_triplanar_blend_sharpness(float p_sharpness) {
-	uv2_triplanar_sharpness = p_sharpness;
-	RS::get_singleton()->material_set_param(_get_material(), shader_names->uv2_blend_sharpness, p_sharpness);
+	// Negative values or values higher than 150 can result in NaNs, leading to broken rendering.
+	uv2_triplanar_sharpness = CLAMP(p_sharpness, 0.0, 150.0);
+	RS::get_singleton()->material_set_param(_get_material(), shader_names->uv2_blend_sharpness, uv2_triplanar_sharpness);
 }
 
 float BaseMaterial3D::get_uv2_triplanar_blend_sharpness() const {