Shader issue with Shuriken

Ok , so i wrote a shader that adds a "bendy" effect to a object ... issue is that it does not work properly with shrunken , when using billboarded shrunken the mesh just disassapers while a mesh type shuriken particle works just fine , let me know if you have any thoughts why it's not working or any walkarounds

here is the CG program

PHP:

CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma fragmentoption ARB_precision_hint_fastest
            #pragma multi_compile_particles


            #include "UnityCG.cginc"


            sampler2D _MainTex;
            fixed4 _TintColor;
            
            float _XBend;
            float _YBend;
            
            struct appdata_t {
                float4 vertex : POSITION;
                fixed4 color : COLOR;
                float2 texcoord : TEXCOORD0;
            } ;


            struct v2f {
                float4 vertex : POSITION;
                fixed4 color : COLOR;
                float2 texcoord : TEXCOORD0;
                #ifdef SOFTPARTICLES_ON
                float4 projPos : TEXCOORD1;
                #endif
            } ;
            
            float4 _MainTex_ST;
            
            v2f vert (appdata_t v)
            {
                v2f o;
                
                
                
                float4 pos = mul(_Object2World, v.vertex);
                  
                  if(pos.x - _WorldSpaceCameraPos.x < 11.0f)
                  {
                      float zDiff = pos.x - _WorldSpaceCameraPos.x;
                      float zDiffSquared = zDiff * zDiff;
                      float bendAmountX = zDiffSquared * _XBend;
                    float bendAmountY = zDiffSquared * _YBend;
                    
                      pos.z += bendAmountX;
                      pos.y += bendAmountY;
                  }
                  
                  float4 lPos = mul(_World2Object , pos);
                  
                  v.vertex = lPos;
                
                o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
                
                #ifdef SOFTPARTICLES_ON
                o.projPos = ComputeScreenPos (o.vertex);
                COMPUTE_EYEDEPTH(o.projPos.z);
                #endif
                o.color = v.color;
                o.texcoord = TRANSFORM_TEX(v.texcoord,_MainTex);
                return o;
            }


            sampler2D _CameraDepthTexture;
            float _InvFade;
            
            fixed4 frag (v2f i) : COLOR
            {
                #ifdef SOFTPARTICLES_ON
                float sceneZ = LinearEyeDepth (UNITY_SAMPLE_DEPTH(tex2Dproj(_CameraDepthTexture, UNITY_PROJ_COORD(i.projPos))));
                float partZ = i.projPos.z;
                float fade = saturate (_InvFade * (sceneZ-partZ));
                i.color.a *= fade;
                #endif
                
                return 2.0f * i.color * _TintColor * (tex2D(_MainTex, i.texcoord).a * i.color.a * 2.0f);
            }
            ENDCG 



This part actually does the bending

PHP:

    float4 pos = mul(_Object2World, v.vertex);
                  
                  if(pos.x - _WorldSpaceCameraPos.x < 11.0f)
                  {
                      float zDiff = pos.x - _WorldSpaceCameraPos.x;
                      float zDiffSquared = zDiff * zDiff;
                      float bendAmountX = zDiffSquared * _XBend;
                    float bendAmountY = zDiffSquared * _YBend;
                    
                      pos.z += bendAmountX;
                      pos.y += bendAmountY;
                  }
                  
                  float4 lPos = mul(_World2Object , pos);
                  
                  v.vertex = lPos;
             


This is what the shader does in game

 

_Object2World won't work with a particle system. The position is in camera space rather than object space. To get the world position of a particle, see here;

http://forum.unity3d.com/threads/82640-Particle-World-Space-Coords

 

Worked , thank you

 

Sorry to revive an old thread, but I'm pretty much doing the same thing and using this solution does not work Did you have to do anything else to get particles to render properly?

Is using _World2Object after the transformations still okay?