Fix sidedness check in material. Also remove SIDE built-in.

drivers/gles3/shader_compiler_gles3.cpp

@@ -806,7 +806,6 @@ ShaderCompilerGLES3::ShaderCompilerGLES3() {
 	actions[VS::SHADER_SPATIAL].renames["SCREEN_UV"] = "screen_uv";
 	actions[VS::SHADER_SPATIAL].renames["SCREEN_TEXTURE"] = "screen_texture";
 	actions[VS::SHADER_SPATIAL].renames["DEPTH_TEXTURE"] = "depth_buffer";
-	actions[VS::SHADER_SPATIAL].renames["SIDE"] = "side";
 	actions[VS::SHADER_SPATIAL].renames["ALPHA_SCISSOR"] = "alpha_scissor";
 
 	//for light
@@ -847,6 +846,8 @@ ShaderCompilerGLES3::ShaderCompilerGLES3() {
 
 	actions[VS::SHADER_SPATIAL].render_mode_defines["skip_vertex_transform"] = "#define SKIP_TRANSFORM_USED\n";
 	actions[VS::SHADER_SPATIAL].render_mode_defines["world_vertex_coords"] = "#define VERTEX_WORLD_COORDS_USED\n";
+	actions[VS::SHADER_SPATIAL].render_mode_defines["cull_front"] = "#define DO_SIDE_CHECK\n";
+	actions[VS::SHADER_SPATIAL].render_mode_defines["cull_disabled"] = "#define DO_SIDE_CHECK\n";
 
 	actions[VS::SHADER_SPATIAL].render_mode_defines["diffuse_burley"] = "#define DIFFUSE_BURLEY\n";
 	actions[VS::SHADER_SPATIAL].render_mode_defines["diffuse_oren_nayar"] = "#define DIFFUSE_OREN_NAYAR\n";

drivers/gles3/shaders/scene.glsl

@@ -1615,7 +1615,7 @@ void main() {
 
 	float alpha = 1.0;
 
-#ifdef METERIAL_DOUBLESIDED
+#if defined(DO_SIDE_CHECK)
 	float side=float(gl_FrontFacing)*2.0-1.0;
 #else
 	float side=1.0;

scene/resources/material.cpp

@@ -753,7 +753,7 @@ void SpatialMaterial::_update_shader() {
 	if (features[FEATURE_REFRACTION] && !flags[FLAG_UV1_USE_TRIPLANAR]) { //refraction not supported with triplanar
 
 		if (features[FEATURE_NORMAL_MAPPING]) {
-			code += "\tvec3 ref_normal = normalize( mix(NORMAL,TANGENT * NORMALMAP.x + BINORMAL * NORMALMAP.y + NORMAL * NORMALMAP.z,NORMALMAP_DEPTH) ) * SIDE;\n";
+			code += "\tvec3 ref_normal = normalize( mix(NORMAL,TANGENT * NORMALMAP.x + BINORMAL * NORMALMAP.y + NORMAL * NORMALMAP.z,NORMALMAP_DEPTH) );\n";
 		} else {
 			code += "\tvec3 ref_normal = NORMAL;\n";
 		}

servers/visual/shader_types.cpp

@@ -109,7 +109,6 @@ ShaderTypes::ShaderTypes() {
 	shader_modes[VS::SHADER_SPATIAL].functions["fragment"].built_ins["DEPTH_TEXTURE"] = ShaderLanguage::TYPE_SAMPLER2D;
 	shader_modes[VS::SHADER_SPATIAL].functions["fragment"].built_ins["SCREEN_UV"] = ShaderLanguage::TYPE_VEC2;
 	shader_modes[VS::SHADER_SPATIAL].functions["fragment"].built_ins["POINT_COORD"] = constt(ShaderLanguage::TYPE_VEC2);
-	shader_modes[VS::SHADER_SPATIAL].functions["fragment"].built_ins["SIDE"] = constt(ShaderLanguage::TYPE_FLOAT);
 	shader_modes[VS::SHADER_SPATIAL].functions["fragment"].built_ins["ALPHA_SCISSOR"] = ShaderLanguage::TYPE_FLOAT;
 
 	shader_modes[VS::SHADER_SPATIAL].functions["fragment"].built_ins["WORLD_MATRIX"] = constt(ShaderLanguage::TYPE_MAT4);