Let's create a material for this new mesh. Every element of the ivy has a different ID so you can use a Multi/Sub-Object material. Now you can apply a VRayMtl with a different ID for each element (Fig.13).
Click on None, select VRayMtl and put the leaf texture in the diffuse slot (you can find the textures in the downloaded files).
Copy the diffuse texture to the opacity slot and open the bitmap parameters. In the mono channel output change the RGB intensity to Alpha (this texture contains its own alpha).
Do the same with the other leaf texture (Fig.14).
It's time to render so open the V-Ray render setup. For a better quality I have activated the Ambient Occlusion (Indirect Illumination: GI).
Activate the environment with an HDR image.
On the V-Ray camera, activate Depth of Field and activate Get From Camera and it will then use the target camera to blur the image. Use the aperture to change the intensity of the DoF.
To reduce the noise open the Adaptive subdivision image sampler. The Clr thresh setting controls the noise filter (low = better quality, but a slower render)(Fig.15).
After a few hours (720p) your render will look like this (Fig.16).
To get a realistic final image I have used Photoshop to change the contrast, lighting color and add some film grain (Fig.17).
Thanks for reading this tutorial, I hope you enjoyed it.