Representation　and　rendering　techniques　of　point　models　are　important　in　computer　graphics.　The　main　drawbacks　of　current　ray　tracing　methods　for　point　models　are　coarse　rendering　effects　in　the　parts　of　silhouettes　and　sharp　features　and　high　computation　cost.　We　propose　a　ray　tracing　method　for　point　models,　based　on　the　height　difference　function　defined　by　blending　projective　distances　between　the　point　of　ray　and　the　corresponding　splats.　Our　method　performs　high　rendering　qualities　in　particular　in　the　parts　of　silhouettes　and　sharp　features,　because　the　height　difference　function　precisely　approximates　geometric　features　in　the　joint　part　of　splats.　Moreover,　the　computation　of　intersection　of　our　method　is　viewpoint-independent.　The　experiments　show　that　our　method　performs　good　rendering　quality　and　has　high　convergence　rate.　©　2011　ACM.