As v0.7 slowly stabilises I’m kicking off the tutorial series with a look at de-noising Radiance images generated with LiVi.
Blender has a nice image de-noising capability that can be used quite effectively with Radiance images. De-noising does not replace higher accuracy analyses – ‘Low’ accuracy settings will still generally produce overall lower luminance and illuminance values, especially in interior scenes – but this is a nice trick to get cleaner images with reduced simulation time.
Comparison between the original rpict image and it’s de-noised version
Bug reports and questions can be posted on the Google Group.
I have now uploaded a video tutorial covering the basics of Radiance simulation with the LiVi component of the VI-Suite. The video concentrates on the options within the relevant nodes and the Radiance material options. One thing I should probably reiterate is that a single Blender object can have more than one Radiance material attached as Blender allows you to associated materials with each individual face. The example below shows a red glass sphere with some blue plastic faces.
Radiance per face materials
Also a version from today or later should be used to correspond completely with the options I talk about.
Otherwise I think the video mentions everything else I wanted to say and, as ever, can be viewed below.
I have, I believe, finished adding features to the VI-Suite, for now, and I am now moving into bug-fixing mode. I do not have the access to other computing platforms that I used to have due to the pandemic, so I am interested to hear if there are any activation issues with v0.6 on OS X, Windows and different flavours of Linux.
The zip file of the source code can be downloaded from https://github.com/rgsouthall/vi-suite06/archive/master.zip. This zip file should be installable directly from Blender’s addon preferences window. I have been working purely with Blender 2.83.6 LTS, and while it may work on later Blender versions I am primarily interested in any activation issues with 2.83.6 LTS.
I have not yet finished updating the user manual for v0.6 but for simple sun path, shadow mapping, SVF and LiVi (Radiance) calculations the process is quite similar to v0.4 and the tutorial videos for that release will hopefully give you enough to get started. EnVi (EnergyPlus) and FloVi (OpenFOAM) have changed quite a bit, and I advise waiting for updated documentation before trying those components. I will post here again when a basic manual is available. Tutorial videos will follow after that.
As some people have been asking what my plans are regarding a Blender 2.8 version of the VI-Suite, I thought I would post an update.
The eagle-eyed amongst you may have noticed that the title of this post skips a version. v0.5 was going to be the last VI-Suite version of the 2.7 series but as 2.8 is now out I decided to roll those changes in to v0.6.
Over the last couple of weeks sun path, wind rose, shadow maps, sky view factor and LiVi have all been, at least in part, transfered over. I am in the process of tranferring EnVi over. There are many bugs remaining, and I would not say v0.6 is ready for usage, but good progress is being made. I’m hopeful that early next year an initial release might be ready.
Once things have stabilised a bit I will post the link to the github repository here.
I have just uploaded VI-Suite 0.4.13 to the download links at http://arts.brighton.ac.uk/projects/vi-suite/downloads. Changes in this version can be seen in the Changelog. One of the main new features of this version is the LIVi image nodes which enables the generation and manipulation of Radiance images for falsecolour metric visualisation and glare analysis.
Images can be generated in parallel on multi-core machines when using OS X and Linux. Unfortunately the methodology employed will not work on Windows.
As ever the tutorial video below explains their operation.
This tutorial is basically a follow up to the Radiance Patterns tutorial and details how normal maps can be used to specify Radiance textures. Textures in Radiance terminology is a perturbation to the surface normal to give the impression that the surface has detailed physical features. If for example a point on a surface has its normal perturbed towards a light source the point will receive more light than if the surface normal is perturbed away.
Although, like Radiance patterns, textures are not often necessary for numerical lighting simulation, and indeed are ignored if they are on an illuminance sensing surface, they can provide extra realism to visual Radiance renders and there are certain circumstances where they may be useful numerically and/or save time by not requiring the creation of detailed physical geometry.
Radiance visual and falsecolour rendering of Blender’s classroom scene
The VI-Suite can simulate artificial as well as natural lighting. Three main methods are available:
Specifying a Radiance light material to mesh elements.
Associating an IES file with a Blender lamp.
Associating an IES file with a Blender mesh plane to create an array of lights.
IES files, which are text files describing the brightness of a lamp or luminaire from different viewing angles, are released by manufacturers for their specific lighting products and can usually be downloaded from their websites. This gives the opportunity to see how real world products will illuminate a scene visually and with the VI-Suite numerically.
As ever, the video below describes these three methods.
As of version 0.4.7 the VI-Suite can now use Blender’s UV image mapping system to create image based Radiance patterns. In the example Radiance rendering below an image texture has been mapped to the wall and picture to create a diffuse reflecting Radiance image pattern, and to the window to create a transparent one.
Radiance geometric and sky text descriptions can be accessed, edited and exported via the ‘VI Text Edit’ node. Radiance results can be exported in comma separated CSV format with the ‘VI CSV Export’ node.
The short video below shows how to use these two nodes.
Blender has very good animation capabilities and the VI-Suite uses this animation system to allow time and/or geometry based parametric analysis with Radiance.
The video below demonstrates how to enable a time and mesh geometry based parametric lighting analysis.