OGRE版本1.7.1的Sample裡包含了地形的示例，且用到了PSSM+LiSPSM。

今天嘗試把Character的Sinbad模型擺到地形上，不過模型的材質本身不支援PSSM。

看了下地形示例的實現，發現它在給Shader傳PSSM分界點資料時，用了把模板材質clone一份，再設定diffusemap和pssm分界點的方法，相當讓人無語....

MaterialPtr ret = MaterialManager::getSingleton().getByName(matName); MaterialPtr baseMat = MaterialManager::getSingleton().getByName("Ogre/shadow/depth/integrated/pssm"); ret = baseMat->clone(matName); Pass* p = ret->getTechnique(0)->getPass(0); p->getTextureUnitState("diffuse")->setTextureName(textureName); Vector4 splitPoints; const PSSMShadowCameraSetup::SplitPointList& splitPointList = static_cast<PSSMShadowCameraSetup*>(mPSSMSetup.get())->getSplitPoints(); for (int i = 0; i < 3; ++i) { splitPoints[i] = splitPointList[i]; } p->getFragmentProgramParameters()->setNamedConstant("pssmSplitPoints", splitPoints);

如果有幾百種不同貼圖的物件，就得在程式碼裡手動為每一個物件設定diffusemap和pssm分界點，前者其實在材質指令碼中可以用繼承來覆蓋，後者其實整個場景用到的資料都是一樣的。好在OGRE增加了shared_params，可以多個shader共享相同的引數，在程式碼裡只設置一遍就可以了。

修改後的fp:

shared_params pssm_params { shared_param_named pssmSplitPoints float4 } fragment_program Ogre/shadow/receiver/depth/pssm3/fp cg { source depthshadowobject.cg profiles ps_2_x arbfp1 entry_point main_fp compile_arguments -DSHADOWCASTER=0 -DDEPTH_SHADOWCASTER=0 -DDEPTH_SHADOWRECEIVER=1 default_params { param_named_auto materialAmbient derived_ambient_light_colour // shadow samplers are indexes 1/2/3 param_named_auto inverseShadowmapSize0 inverse_texture_size 1 param_named_auto inverseShadowmapSize1 inverse_texture_size 2 param_named_auto inverseShadowmapSize2 inverse_texture_size 3 //SET THIS MANUALLY! //param_named pssmSplitPoints 0 0 0 0 shared_params_ref pssm_params } }

c++:

Vector4 splitPoints; const PSSMShadowCameraSetup::SplitPointList& splitPointList = static_cast<PSSMShadowCameraSetup*>(mPSSMSetup.get())->getSplitPoints(); for (int i = 0; i < 3; ++i) { splitPoints[i] = splitPointList[i]; } GpuSharedParametersPtr p = GpuProgramManager::getSingleton().getSharedParameters("pssm_params"); p->setNamedConstant("pssmSplitPoints", splitPoints);