Ogre 创建角色对象的边缘线效果

http://www.ogre3d.org/tikiwiki/Create+outline+around+a+character

Here is a script of user Telchar, which shows how to create an outline around a character, which works without shaders.

Screenshot of this effect, used in the game Torchlight:

 

material some/random/material/with/rim/effect
{
   technique
   {
      pass
      {
         texture_unit
         {
            texture yourtexturehere.png
         }
 
         //rim lighting
         texture_unit
         {
            cubic_texture rim.dds combinedUVW
            tex_address_mode clamp
            colour_op_ex add src_texture src_current
            colour_op_multipass_fallback one one
            env_map cubic_normal
         }
      }
   }
}

 
Here is the c++ code to do the same:

/*
    rim lighting
    see: http://www.ogre3d.org/tikiwiki/Create+outline+around+a+character
 
*/
#pragma once
 
#include <Ogre/OgreEntity.h>
#include <Ogre/OgreSubEntity.h>
#include <Ogre/OgreSubMesh.h>
#include <Ogre/OgreString.h>
#include <Ogre/OgreMaterial.h>
 
 
/*
    add the rim lighting effect to an entity.
*/
void highlight (Ogre::Entity* entity)
{
    unsigned short count = entity->getNumSubEntities();
 
    const Ogre::String file_name = "rim.dds";
    const Ogre::String rim_material_name = "_rim";
 
    for (unsigned short i = 0; i < count; ++i)
    {
        Ogre::SubEntity* subentity = entity->getSubEntity (i);
 
        const Ogre::String& old_material_name = subentity->getMaterialName();
        Ogre::String new_material_name = old_material_name + rim_material_name;
 
        Ogre::MaterialPtr new_material = MaterialManager::getSingleton().getByName (new_material_name);
 
        if (new_material.isNull())
        {
            MaterialPtr old_material = MaterialManager::getSingleton().getByName (old_material_name);
            new_material = old_material->clone (new_material_name);
 
            Pass* pass = new_material->getTechnique(0)->getPass(0);
            Ogre::TextureUnitState* texture = pass->createTextureUnitState();
            texture->setCubicTextureName (&file_name, true);
            texture->setTextureAddressingMode (TextureUnitState::TAM_CLAMP);
            texture->setColourOperationEx (Ogre::LBX_ADD, Ogre::LBS_TEXTURE, Ogre::LBS_CURRENT);
            texture->setColourOpMultipassFallback (Ogre::SBF_ONE, Ogre::SBF_ONE);
            texture->setEnvironmentMap (true, Ogre::TextureUnitState::ENV_NORMAL);
        }
 
        subentity->setMaterial (new_material);
    }
}
 
/*
    remove the rim lighting effect from an entity.
*/
void unhighlight (Ogre::Entity* entity)
{
    unsigned short count = entity->getNumSubEntities();
 
    for (unsigned short i = 0; i < count; ++i)
    {
        Ogre::SubEntity* subentity = entity->getSubEntity (i);
        Ogre::SubMesh* submesh = subentity->getSubMesh();
 
        const Ogre::String& old_material_name = submesh->getMaterialName();
        const Ogre::String& new_material_name = subentity->getMaterialName();
 
        // if the entity is already using the original material then we're done. 
        if (0 == stricmp (old_material_name.c_str(), new_material_name.c_str()))
            continue;
 
        // otherwise restore the original material name.
        subentity->setMaterialName (old_material_name);
 
    }
}

 
Download of file rim.dds:
http://www.ogre3d.org/forums/download/file.php?id=2022

The code was published here:
http://www.ogre3d.org/forums/viewtopic.php?p=368918#p368918

Similar version:
http://www.ogre3d.org/forums/viewtopic.php?f=8&t=59079

For questions and feedback, please use this forum topic:
http://www.ogre3d.org/forums/viewtopic.php?f=8&t=59079

I did not find any other good demo of how to use the stencil in OGRE.

I recommend to add this demo (or similar) to the OGRE demos that come with the OGRE source download.

Here is the exe ready to run:
http://assaframan.googlepages.com/StencilGlow_exe.zip

Here is the code:
http://assaframan.googlepages.com/StencilGlow_src.zip

Here are some screenshots of my current work.








Here is the exe (download and run): http://assaframan.googlepages.com/outline.zip

I did something similar to this article: http://www.codeproject.com/opengl/Outline_Mode.asp

This is only good for an outline and not for a glow effect.

Also – it only works in openGL and I had to add _setLineWidth function to the render system – and the Line Width only works with openGL. You can’t set the wireframe line thickness in DirectX.

If anyone wants the code – post a replay.

I will create a glow using a similer technique to the one in nebukadnezzar code.

The nice thing about the outlines technique in the screenshots is that the outlines stay with the same thickness no matter if you are far or near.

I didn't get nice results with the stencil+shaders.

Here is the best I have got until now:




Here is the exe (download and run):
http://assaframan.googlepages.com/glow.zip

Here is the source:
http://assaframan.googlepages.com/glow_code.zip

Not a nice glow - but a nice code sample of how to use the stencil with OGRE.

Watch out for my OGRE related tweets here.

Assaf Raman

OGRE Team Member

 

Posts: 3092

Kudos: 79

Joined: 11 Apr 2006

Location: TLV, Israel

Top

by psquare » Tue Dec 26, 2006 5:28 am

I did something like this before:

1. Programmatically add a pass at the end of all passes of the technique you are using.

2. Render to texture the object(s)

3. Use this rendered texture as a projective texture in the pass that you added. In the pass you can have a shader which scales the original color.

You can use something like a toon shader as your last pass shader.

If dot(normal, viewVector) > treshold
color = glow color
else
color = original color

This will accurately do the edge detection for you.



Note that I add a pass, so that I do this non-invasively (do not modify the existing passes).


To do a glow around the edges, you can add a bloom shader as Falagard mentions.You can accomplish this using compositor framework of Ogre.

There is a sample for bloom in the OgreSDK. There are also various scene shaders (compositor effects (.fx) ) in the Direct X SDK.