学步园

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

今天尝试把Character的Sinbad模型摆到地形上，不过模型的材质本身不支持PSSM。

看了下地形示例的实现，发现它在给Shader传PSSM分界点数据时，用了把模板材质clone一份，再设置diffusemap和pssm分界点的方法，相当让人无语....

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

如果有几百种不同贴图的物件，就得在代码里手动为每一个物件设置diffusemap和pssm分界点，前者其实在材质脚本中可以用继承来覆盖，后者其实整个场景用到的数据都是一样的。好在OGRE增加了shared_params，可以多个shader共享相同的参数，在代码里只设置一遍就可以了。

修改后的fp:

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

c++:

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