Morph target shaders shouldn't clamp influences to positive. (#23264)

src/renderers/shaders/ShaderChunk/morphnormal_vertex.glsl.js

@@ -10,7 +10,7 @@ export default /* glsl */`
 
 		for ( int i = 0; i < MORPHTARGETS_COUNT; i ++ ) {
 
-			if ( morphTargetInfluences[ i ] > 0.0 ) objectNormal += getMorph( gl_VertexID, i, 1, 2 ) * morphTargetInfluences[ i ];
+			if ( morphTargetInfluences[ i ] != 0.0 ) objectNormal += getMorph( gl_VertexID, i, 1, 2 ) * morphTargetInfluences[ i ];
 
 		}
 

src/renderers/shaders/ShaderChunk/morphtarget_vertex.glsl.js

@@ -12,11 +12,11 @@ export default /* glsl */`
 
 			#ifndef USE_MORPHNORMALS
 
-				if ( morphTargetInfluences[ i ] > 0.0 ) transformed += getMorph( gl_VertexID, i, 0, 1 ) * morphTargetInfluences[ i ];
+				if ( morphTargetInfluences[ i ] != 0.0 ) transformed += getMorph( gl_VertexID, i, 0, 1 ) * morphTargetInfluences[ i ];
 
 			#else
 
-				if ( morphTargetInfluences[ i ] > 0.0 ) transformed += getMorph( gl_VertexID, i, 0, 2 ) * morphTargetInfluences[ i ];
+				if ( morphTargetInfluences[ i ] != 0.0 ) transformed += getMorph( gl_VertexID, i, 0, 2 ) * morphTargetInfluences[ i ];
 
 			#endif