Ogre : How to actually get morph animations to work in the engine

Introduction

Ogre features both Morph animation and Pose animation. The difference between these two techniques is explained in the
manual

. However,
what is not explained there, is how to actually get morph animations to work in the engine. This article provides explanation of this.

Code in the engine

Morph animation works like skeletal animation from the in-engine point of view. If there is a morph animation in the mesh, then you can get it to animate like this:

Morph AnimationState usage

//get the animation
Ogre::AnimationState* state = entity->getAnimationState("morph");
state->setEnabled(true);

//do this every frame to play the animation
float time = 0.1f;
state->addTime(time);

An example shader

You can let OGRE do software blending of the morph animation, but you can also do it in hardware. The shader will only get morph data from the engine if its AnimationState is enabled, so the code above is needed.

Morph.material

vertex_program Cg_Morph_VP cg
{
source Morph.cg
entry_point Morph_VP
profiles vs_1_1

includes_morph_animation true

default_params
{
param_named_auto worldViewProjMatrix worldviewproj_matrix
param_named_auto animationPhase animation_parametric
}
}

material Morph
{
technique
{
pass
{
vertex_program_ref Cg_Morph_VP
{
}
}
}
}

Morph.cg

Note that the second position is put in the first free texture coordinate.

void Morph_VP
(
float3 position1    : POSITION,
float2 uv        : TEXCOORD0,
float3 position2    : TEXCOORD1,

out float4 oPosition : POSITION,

uniform float4x4 worldViewProjMatrix,
uniform float animationPhase
)
{
float3 blendedPosition = lerp(position1, position2, animationPhase);
oPosition = mul(worldViewProjMatrix, float4(blendedPosition, 1));
}

注意事项：

position2是放到TEXCOORD1的位置，如果你自己本身有N个纹理坐标，那么position的位置会被放到末尾，即TEXCOORDN+1

原文链接：http://www.ogre3d.org/tikiwiki/tiki-index.php?page=Morph+animation