ok in Octane,
1.create a normal c4d background object, assign any img or video png’s [octane meterial]
2. in c4d render settings , select octane render, select ‘overwrite kernel settings’ tab
3. select direct lighting option , and enable alpha channel and disable keep environment.
4. in octane live viewer , select settings option and enable alpha channel and disable keep environment.
In Redshift,
just use Domelight and enable backplate option
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