I went a slightly different road.
First i drew a 4096x4096 16 bit image with no alpha:
(edit* after all i tried with 1024x1024 image, and it is more than enough for now)
Good to see your solution, your displacement map looks great. But what are these thin black lines shooting out of the cathedral?
Those lines show the direction of light portals. I dont use them actually.
I like your cathedral very much, nice design.
I found this today, for the outside shots maybe we can use this, the fundamentals are similar to what we learned in the bunny project about making the grass from images. Sooo much to learn 
Ah that explains, I didn’t use the light portals in this scene, so I could not figure out what those lines were. We start to make good progress with this section of the course we are almost at the end. Looking forward to see both our end result.
Thanks for sharing these great tutorials with me, i’m definitely planning to use some trees in my outside shots. But all depends on how my system is holding. I still remember the render times of the bunny scene…
@Bram_van_Vliet
Iam already a bit nervous about VRAM usage. Iam working on a sandstone sarcophagus, which is rather highpoly because of displacement and with the hires textures i use in the scene the memory usage of GPU jumps to 4,7GB 
Need some optimisation on them. OR we go for the GTX 1080ti with 11GB of VRAM 
hahaha I totally agree, I’m nervous about that to… Specially because I don’t have a backup to fall back to… my poor GPU. I’m not sure if I have a new render system before the end of this chapter. Still in the orientation phase. So much options to choose from. I want to do it right… have have to use this system for the next couple of years .
Thanks again to pointing me to this awesome tutorial… I am going to watch it now…
