How to retrieve runtime color of vertices of a model in Ogre3D?

Question

I have loaded an entity in my scene. I want to use vertices' properties in my machine vision program. My entity model has bones that I change these bones at runtime. therefore I want runtime attributes of vertices. these attributes are POSITIONS and NORMAL and COLOR. For this purpose, I use codes like below:

Ogre::VertexData* vertex_data = myEntity->_getSkelAnimVertexData();
vertex_data->vertexDeclaration->findElementBySemantic(Ogre::VES_POSITION);

Method _getSkelAnimVertexData retrieves runtime vertices positions and works correctly. VES_DIFFUSE element is a constant ARGB type that is not changed when model's bones changed. these values is read from my model's mesh file (but not change in runtime). My question is how to retrieve runtime color of vertices of a model with considering the effects of different light and diffuse property?

it's probable you'll get sooner an answer if you ask on Ogre's forum. There are more Ogre active users there than in SO — CoffeDeveloper, Dec 27 '14 at 13:13

score 0 · Answer 1 · answered Jul 17 '15 at 12:22

for (int i = 0; i < entity->getMesh()->getNumSubMeshes(); ++i) {
    SubMesh* submesh = entity->getMesh()->getSubMesh(i);
    Ogre::VertexData* vertexData = submesh->vertexData;                 
    const Ogre::VertexElement* colorElement = vertexData->vertexDeclaration->findElementBySemantic(Ogre::VES_DIFFUSE);
    Ogre::HardwareVertexBufferSharedPtr vertexBuffer = vertexData->vertexBufferBinding->getBuffer(colorElement->getSource());
    unsigned char* colors = static_cast<unsigned char*>(vertexBuffer->lock(Ogre::HardwareBuffer::HBL_NORMAL));
    float* color;
    for (int j = 0; j < vertexData->vertexCount; ++j) {
        vertexElement->baseVertexPointerToElement(colors, (void **)&color);
        ColourValue ogreColor(color[0], color[1], color[2], color[3]);
        colors += vertexBuffer->getVertexSize();
    }
    vertexBuffer->unlock();
}

I just don't know if it actually returns a float[4] or if it's just a float[3].

Hope it helps. :)

How to retrieve runtime color of vertices of a model in Ogre3D?

1 Answers1