saajjj
08-05-2003, 06:55 AM
hello,
i'm working on a project which shows a 3d car travelling on a 'real' road. By real i mean I'll take video footage of a street and i want to animate my car on that.
The whole idea is in it's infancy and i'm just trying to solve potential problems, and the first few that come to mind are:
1. how do i make the reflection of the buildings appear on the car. Obviously the reflection will be of the side that the camera is not facing, so i think that i'll have to take two shots.. one where i plan to put in my car and the other shot would be of what the car body will reflect. Is that how this is 'normally' done? And then during rendering i can just project the reflection movieclip on a grid behind the camera.
2. Another one of my shots involves a human walking around the car. Woudl blue screening a human walking around in a circle be the way to do it? Then i can use masking when the human is behind the car or vice versa.
3. how do i render out just shadows? this is for making car shadows for the road. erm.. the car will be flying :) so i need to render out jsut the shadows which i'll comp on the road. The only way i can get shadows is on a grid, but i'm sure there must be some way of just getting shadows with alpha values so that they can be placed on anything. i tried experimenting with primary/secondary rays but it didn't seem to work.
any/all help appreciated.
cheers
i'm working on a project which shows a 3d car travelling on a 'real' road. By real i mean I'll take video footage of a street and i want to animate my car on that.
The whole idea is in it's infancy and i'm just trying to solve potential problems, and the first few that come to mind are:
1. how do i make the reflection of the buildings appear on the car. Obviously the reflection will be of the side that the camera is not facing, so i think that i'll have to take two shots.. one where i plan to put in my car and the other shot would be of what the car body will reflect. Is that how this is 'normally' done? And then during rendering i can just project the reflection movieclip on a grid behind the camera.
2. Another one of my shots involves a human walking around the car. Woudl blue screening a human walking around in a circle be the way to do it? Then i can use masking when the human is behind the car or vice versa.
3. how do i render out just shadows? this is for making car shadows for the road. erm.. the car will be flying :) so i need to render out jsut the shadows which i'll comp on the road. The only way i can get shadows is on a grid, but i'm sure there must be some way of just getting shadows with alpha values so that they can be placed on anything. i tried experimenting with primary/secondary rays but it didn't seem to work.
any/all help appreciated.
cheers