Fully Calibrated PG SKIES

A little teaser of a big update to PG SKIES that I am working on.

Completely re-processed HDRs with correct sun vs sky balance and calibrated back to the original camera raw files so that the intensity matches real world exposure values and therefore also corona/vray/fstorm sun & sky systems.

CABINS - Arch Viz Challenge VII

Ronen Bekerman is hosting another excellent arch viz challenge entitled 'Cabins' which you can read all about at cabins.ronenbekerman.com

One of my favourite cabins, 'The Box' by Ralph Erskine, as shot by  Ake E:son Lindman

One of my favourite cabins, 'The Box' by Ralph Erskine, as shot by Ake E:son Lindman

I'll be helping judge the entries, along with Teddy Bergsman from Quixel, Andreas Landgren from Tomorrow as well as Gianpiero from SoA and Ronen himself. 

Looking forward to seeing what you all come up with!



For anyone like myself hoping for some quality time spent in front of the computer these Christmas holidays, here is a small gift from PG SKIES to help with whatever 3d scene you are working on.

Use the code XMASGIFT at checkout to get 25 euros off your order. The only condition is you need to have an account at PG SKIES and be signed in. The code is valid for the rest of 2017.

Alternatively click here and it should apply the discount automatically. 


'1958 Night'

'1958 Night'

As usual PG SKIES is taking part in the Black Friday sales:

BLACK20 - 20% off entire order
BLACK30 - 30% off orders over 100 euros
BLACK40 - 40% off orders over 250 euros
BLACK50 - 50% off orders over 500 euros

Please remember to type in the code at checkout to get the discount.

The sale starts at 5pm on the 23 November and runs till the end of the month.


PG TIPS - Clipping planes focal point trick

A handy trick I use all the time to set your focus point in a more intuitive way. It is especially useful if, like me, you prefer working in one big viewport and don't want to switch to the top viewport in order to measure the distance to your object.


1. In your vray or physical camera, activate clipping and then move either the near or far clipping plane to see the distance from the camera to where you want to set the focus point. 

2. Note the distance.

3. Put that value into the override focus distance on your camera. Easy!

MOHIT Sanchaniya & PG SKIES

I was delighted to learn that Mohit Sanchaniya had used PG SKIES in this recreation of Tham & Videgard architect's Kalmar Kontmuseut for the Tomorrow Arch Viz competition.

Mohit has since published a nice making-of on www.ronenbekerman.com

If you have used PG SKIES in on of your projects and you would like to see your images published here, on facebook or on instagram please email me: peter@peterguthrie.net

Eleonora Galimberti & PG SKIES

New renders from last year's State of Art Academy PG Lighting Masterclass by Eleonora Galimberti. (Click on the thumbs for lightbox)

1714 Clear Sky and 1409 Overcast were the PG SKIES used.

We are very excited that Eleonora will be joining us at The Boundary on Monday! Another success story for Gianpiero and Roberto at SoA.


We use Corona almost exclusively at The Boundary, but after so many years of using vray I still follow development closely and use it for things that corona cant do. In converting an old project, 152 Elizabeth Street to corona, I thought it would be a good time to write a blog post on the differences between the two rendering engines and also to see how much Vray has improved since I used it to render this project in 2014/15.

Final Original Image rendered at 6k (Including photoshop work) (click for lightbox)

The first thing I did was render in Vray using my original settings but at 2k resolution so we can see what an unprocessed Vray version looks like. This took 1hr 15 minutes at a bucket noise threshold of 0.007. (amazing seeing buckets again!)

Vray render using my old settings - 1hr 15mins

Next I tried Vray 3.5 at default settings, which seems to be what Vlado suggests to most people. I switched to brute force settings in Vray years ago and its great to see that with developments in software and hardware this is now the norm. This time it took 58 minutes.

Vray render using default settings (progressive) - 58mins

Here is a 100% crop between the two versions. My previous settings were 1-100 subdivs and a noise threshold of 0.007, probably had subdivs on materials too (seems so weird to have to think about things like that after using corona for 2 years). I can't see any real difference here so not sure why anyone in arch viz would deviate from the defaults in vray these days.

bucket brute force vs progressive

Converting a Vray scene to Corona is pretty much a one-click process thanks to the amazing conversion script that comes with corona (I should add that the conversion back to Vray using the script that comes with Vray is also very good should you need to go that way.) Some things to remember though:

  • Vray cameras work fine in Corona, but you might need a coronacameramod to fine tune DOF
  • The vrayhdri map works well in Corona but remember the render multiplier doesn't do anything so adjust your overall multiplier accordingly
  • There is no need for a dome light (plug vrayhdri straight into environment) so remember to take into account any multiplier on the domelight
  • I use vrayhdri and vraycameras, there still aren't equivalents in Corona
  • Corona's displacement is inferior to Vray's. You will need to play with the corona settings to try to match it, especially if you used vray 2d displacement. (Corona 3d displacement has improved a lot but I still miss Vray 2d displacement.)
  • In Corona, you just apply coronafogmtl straight to geometry, no need for a gizmo.
  • Matching vray2sidedmtl with Corona is always a bit hit and miss, I use interactive and tweak till it looks similar

For a comparison between vray and corona, I wanted to see what a 20 minute render would look like in each. Vray after 20mins:

VRAY - 20 minutes render

On to Corona (Latest 1.6 daily) and after matching the exposure, vignetting, colour balance, curves (there are now curves in Corona!!!) this was what I got.  Corona after 20 mins

CORONA - 20 minutes render

After 20 minutes, corona did seem to deal with noise better, especially in the concrete and ceiling areas. The displaced carpet looks way better in vray, despite increasing the quality of displacement in corona from 2px to 1px. Overall I'd say they are pretty similar in terms of quality.

Note the overbright pixels on the vray version

Note the overbright pixels on the vray version

Pushing Corona Further

The joy of working with Corona is in using Interactive rendering to explore new compositions, tweak materials, play with lighting etc. If you haven't tried it you really should. I never got on very well with VrayRT, partly because it required more set-up and because it wasn't the same as a final render. Another thing Corona does very well is lens effects (bloom and glare). For some reason its much easier to get nice results with Corona and you can also tweak them as it is rendering. I'm going to finish with a slightly re-worked version of this scene, made entirely in Corona with no post work at all.

A quick Note on vignetting in Corona: Vignetting in 1.6 finally works as (I believe) it should, in that it doesnt just add what looks like a black overlay, it correctly reduces the exposure at the corners. This now means that really bright areas (sky) will not look artificially dark when you add vignetting. I have never used vignetting in corona for this reason, but now I'll probably use it much more often, as I did with vray.

Final Corona Version

Final Corona Frame Buffer Setting (using Corona 1.6 daily):

Highlight Compression: 5
WB: 4600K
Contrast: 1.0
Saturation: 0.0
Filmic highlights: 0.0 (my advice would be don't use filmic, it often acts strangely)
Filmic shadows: 0.0
Vignette: 1.0
Curves: NO

LUT: Kim Amland's Photographic 01 LUT that mimic real dslrs.

Bloom and Glare:

Bloom intensity: 5.0
Glare Intensity: 1.50
Streak blur: 0.20

Sharpening / Blurring:

Sharpen amount: 1.0
Sharpen radius: 0.250
Blur radius: 1.250

Many thanks to Kim for his work in analysing what dSLRs do to the raw data they capture in order to make them look good. It's very interesting that the quick Corona FB tonemapping I did in this last image resulted in something similar to what took a lot longer in photoshop & Adobe Camera RAW.

I love being able to get amazing looking images straight out of 3dsmax with no post work at all. Next on my wishlist would be colour temperature tint (from green to magenta)... please Ondra & Vlado??

You can read more about the LUTs and download them from his thread on the forum


Since announcing The Boundary in October 2014, we have grown to a team of 12 here in London and are enjoying working with architectural heroes of ours such as Renzo Piano, Richard Rogers, Peter Zumthor, Tadao Ando.

The team will be expanding again soon, so if the prospect of coming and working alongside us interests you then get in touch now! 

jobs@the-boundary.com, or if you prefer, peter@peterguthrie.net

A selection of completed projects, many more to be added soon.

A selection of completed projects, many more to be added soon.