The Phoenix Flowers is a new public realm intervention by 7N Architects in Glasgow, Scotland. I worked on the 3d visualisations in September last year and was very interested to see photos of the completed project by my ex-colleague and friend Dave Morris.
At the time I remember being happy with my work but not completely sure how ‘real’ the images looked. As it turns out, the red carpet and flowers are even more intensely coloured in reality! Take a look at the full set of Dave’s photos here, below are a selection for comparison. When I saw Dave’s photos I felt I had to go back and render a couple of extra views, so the 2 below were done to try and match his compositions.
render:
photo:
render:
photo:
For me, the interesting things to notice were the relative intensities of the highlights (how the Canon 5D dealt with them compared to vray), the colour of the lighting behind the grilles (goes towards yellow in reality despite being red) and that I was pretty lucky in getting the flower petal material looking about right.
This is my complete collection of 54 HDRi skies, the ones already available to buy on 3DOcean are marked with a red logo (you can click through to 3DOcean.net). Feel free to let me know in the comments which ones you think would be useful to you. If you hover over the thumbs you should get the name of the HDRi, and if you click you’ll get a 1000px preview.
Thought I should do a quick tutorial on how I use these HDRi Skydomes I’m selling. Note that this is just one of many possible workflows, and there are probably lots of tricks I’m missing and even things I do completely wrong. I should also say that I work mostly with still images, not animations.
1. Here is a typical architectural scene. It is a model I made of Waro Kishi’s Fukaya house in Japan that never really went anywhere.
2. I use a gamma 2.2 workflow together with reinhard color mapping, so not strictly LWF but shares some of the advantages. I don’t want this to turn into a LWF tutorial or discussion, but this post on cgpov.com pretty much sums up how I feel a gamma corrected workflow helps us as visualisation artists.
The reinhard color mapping helps to control burnt out (overexposed) areas. Screenshot of my color mapping set up: The burn value of the reinhard color mapping typically ranges from .75 for an exterior to 0.05 for an interior. You need to experiment with the value until you gain control over the burnt out areas. Here is an example with a camera pointing at the HDR sky:
For the final render, I use the Vray Frame Buffer, and add a slight s-curve to the output to compensate for the lack of contrast that the gamma corrected workflow introduces:
3. Add a vray dome light and load the exr/hdr using the max bitmap loader. Set the mapping type to environment/spherical. If you are using .hdr files, you can use the vrayHDRi loader instead. It makes no difference whether you use the bitmap loader or the vrayHDRi loader, the vrayHDRi adds a bit more control in that you can control the render multiplier independently from the viewport multplier. Set the output of the .exr to 1 and the vraylight multiplier to 1. If your hdr/exr has no alpha channel it seems you can save quite a bit of memory while rendering (approx 200mb in my case) if you load the exr/hdr as realpixel float rgb rather than the rgba option.
[Click for original size]
4. To rotate the HDR you need to enter a U offset value from 0-1, so to rotate 180 degrees with would enter 0.5, 270 degrees 0.75 etc.
5. Add a vrayphysicalcamera, and set the aperture and shutter speed to something that would work for a typical outdoor scene, like F4, 1/200th & ISO 100. Remember that you are in effect using a completely manual camera, there is no ‘P’ or automatic mode so you need to experiment with different exposures until you get a good result.
[Click for original size]
6. Hit render and see what you get. If it looks too dark/bright I tend to adjust the bitmap’s output rather than the vraylight multiplier, so that I can have a couple of ready setup HDRi’s ready to drag and drop onto the dome light. In the examples below I use an output value of 1.5.
The first HDRi skydome is available on 3docean. It’s a clear blue sky with just a few clouds. I’m hoping to be able to offer packs at a discounted price as well, but that’s dependent on 3docean, so for now it’s just going to be individually. Feel free to let me know what type of skies you would like to see next, the image below is just a selection from many!
UPDATE: The slideshow below will automatically update as I add new HDRi skies.
Slideshow of a recently completed project for Lynas Architecture in Hackney, London.
(Should be high enough resolution to work well in fullscreen mode)
Everything in this scene was 3d, so making the day/cloudy/dusk shots was simply a case of changing the HDR used to light the scene, and turn on/off lights.
For the 7 shots used to make this HDR skydome I used a Canon 1ds mk3 which has superb auto bracketing abilities as well as being very fast and having 21 megapixels. The lens used for these shots was a sigma 8mm fisheye which gives a complete circular image on a full frame dslr. I set the AEB to 7 shots 2 stops apart, which gave exposure times of 0.5s, 1/8, 1/30, 1/125, 1/500, 1/2000 & 1/8000 all at F20. This range of exposures is crucial for capturing the full dynamic range of the sun, which will eventually mean you get good strong shadows when you use the HDR image to light a 3d scene.
- Process raw files to remove chromatic aberration & to ensure white balance is consistent. I do this in Adobe Lightroom (pictured below), where you can copy the develop settings from the first file, and then batch process the remaining ones to save time.
- Export as 16 bit TIFFs
- Load TIFFs into Photomatix or Photoshop to blend into a single HDR, I use Photomatix as it seems to do a better job of removing ghosting artifacts (from moving clouds).
- Load HDR image file into Hugin. Choose lens type as fisheye when importing, and set the Horizontal field of view to 285 degrees (I arrived at this mostly through trial and error!)
- Hugin will complain that more than 1 image is required - ignore.
- Set pitch of image to 90, and adjust yaw so that sun is centred. If you know where the sun is, it helps later on when you come to rotating the skydome in your 3d application.
- in the stitcher tab, I take off soft blending as there is only 1 image, and press the ‘calculate optimal size’ button. Then hit ‘Stitch Now!’ (saving as a tif)
- Open 32bit tif in photoshop, clone out anything you dont want (dust in my case), save as 32 bit exr. Image below shows how the HDR should look when you drag the exposure slider in photoshop.
(click image for high res version on flickr)
Sometime, I’ll follow this up with something about how I use these in 3dsmax & Vray!
The vray override material is a great way of previewing/checking your lighting even when you are a long way into a project. The scene below uses a homemade dusk HDR skydome and vrayIES internal lights which have a colour temperature of 4500 (6000 in the second image) kelvin. I wanted to check the effect 2 alternative IES web files made to the internal lighting in distribution as well as the fancy patterns on the walls. I find having all the materials a neutral colour really helps in balancing natural & artificial light.
To set it up, you first make a mid grey material in the material editor and then drag it into the vray override mtl slot in global switches (in this instance I made a material called ‘200′ which has the rgb values 200,200,200):
then you can specify which objects to exclude from the override material (normally glass) in the include/exclude dialog:
