matte and shadows problem

[stormchaser]

hi mates, so i am trying to compose an animation with moving vehicles and people around the site, so i first rendered a background plate without moving objects and then vehicles and people with rest of the objects as matte. the problem i am facing is that matte objects are not blocking the sun and the vehicles and people are casting full shadows even where the shadows should be cut.. ive made a test scene to explain my point better.

 

1- this is the final result i want to achieve, the blue cylinder is to be added later on.

[ATTACH=CONFIG]42274[/ATTACH]

 

2- so i render a background plate.

[ATTACH=CONFIG]42271[/ATTACH]

 

3- i applied vraymtrwrapper on rest of the objects with typical settings (alpha -1, affect shadow and affect alpha check, no gi on other mattes is also checked) as you can see the problem is the box behind cylinder is not blocking the sun rays and the cylinder is casting full shadows.

[ATTACH=CONFIG]42273[/ATTACH]

 

4- i rendered again, this time unchecking the box "no gi on other mattes" it didnt solve the problem either, now the box does block the light but the whole scene is casting shadows and overlaying it on the background will cause undesirable effects.

[ATTACH=CONFIG]42272[/ATTACH]