resize() {
        // resize render target only if its a child of a shader pass
        if(this._shaderPass) {
            this._setSize();

            this.textures[0].resize();

            // cancel clear on resize
            this.renderer.bindFrameBuffer(this, true);

            if(this._depth) {
                this._bindDepthBuffer();
            }

            this.renderer.bindFrameBuffer(null);
        }
    }
Resizes our RenderTarget (only resize it if it's a ShaderPass scene pass FBO)
*