AccuRender 3 is supplied complete with some light fittings. This tutorial is concerned with how to create entirely new AR3 light fittings and to include them in the AR3 light fitting visual library. Basic directory layout and file management issues were covered in a previous tutorial “MODIFICATION OF AR3 LIGHT BLOCKS & AR3 LIBRARY EDITING”. Readers are directed to read that tutorial first if they are unfamiliar with these issues. All comments refer to the Windows PC platform. The abbreviation AR3 refers to AccuRender Version 3.1.
WARNING - It is essential that you follow these instructions carefully; failure to do so could result, in rare cases, of corruption of your AccuRender installation. You should be aware that re-installation or upgrading of AccuRender might result in overwriting of your modified files unless the correct steps have been taken.
DISCLAIMER - The processes suggested in this tutorial represent modifications to non-critical parts of the normal AccuRender installation. The author expressly disclaims any responsibility for loss of productivity or any other claims arising out of use or misuse of the information contained within this tutorial.
AR3 light blocks are composed of 4 parts: - a 3D model in DWG format, a library picture of the model in EMF format (Enhanced Windows Metafile), a materials selection (optional), and a lamp (or light source) of some type.
To create new light fittings we first need a 3D model. Let’s assume a simple model of a wall mounted quadrant (quarter sphere) style fitting. Two sample DWGs in R14 format are included with this tutorial - Test-wbkt1.dwg and Test-wbkt2.dwg. These models have been built from simple AutoCAD primitives.
First open the Test-wbkt1.dwg. You will see that it is composed of a backplate, a quadrant shaped diffuser, and a lamp (light source). Checking the materials that have been applied you’ll see polished metal for the backplate, transparent yellow plastic for the diffuser, and a self-luminant white light source for the lamp. These are all standard AccuRender or AccuStudio materials. You may of course choose different materials or modify the fitting in some other way for your own use.
If you now load AccuRender and pick the AccuRender Lighting tag, you’ll see I have installed a 60 watt GLS (General Lighting Service or just regular household type) lamp. If you pick its name tag, then Edit, you’ll see under the General tag, how I have set its name, description, wattage, location and size. A regular GLS lamp is about 2½in. diameter, so we have 1¼in. set as the radius. The location setting is a matter of intelligence and a little know-how. If a manufacturer were building this fitting for real then the considerations would be to position the lamp like this: -
Low enough so it can’t be directly seen from normal viewing angles.
High as possible to get the maximum unobstructed light out the open top.
Centered so the light output is balanced left and right.
Not too close to the backplate because the shadowing up the wall will be too strong, but as far away as possible from the diffuser which might melt or burn if someone puts an over-rated lamp into the fitting.
In a location where a burnt-out lamp can be changed without a lot of trouble or special tools.
That’s why it is located where it is. Bear in mind that the real laws of physics apply here and the light really is cut off by any obstruction, so if you place your lamp lower down inside a non-transparent diffuser, the light output will be restricted just like in the real world. Refer to Image 1 below.
NOTE - A point source has been used because we want to simulate the effect where the light is emitted pretty much evenly in all directions from the source.
Under the Color tag you will see a Color Temperature of 3000K has been set. This is close to the color temperature of incandescent (filament) lamps. In reality they vary from around 2750K - 3100K.
Under the Special tag you will see that INVISIBLE has not been checked - we want to see the light source in this case.
Next we want to add this fitting to the standard AccuRender library of lighting blocks. We save it into the AR3/ ACAD/ SUPPORT/ LIGHTS directory. See the previous tutorial for an explanation of this step.
Now we create an EMF (Enhanced Windows Metafile) format thumbnail image for the library by entering “ar_emf” at the command line. As detailed in the previous tutorial, you may want to freeze some layers or do a HIDE before this step. This EMF image is stored in the AR3/ COMMON/ SUPPORT/ LIGHTS directory. Again refer to the previous tutorial for a full explanation.
Thaw any frozen layers and make sure you have saved the DWG in this new location.
Now you have saved the fitting we’ll add it to the AR3 visual library.
Open AR3 and go to Tools/ Light Fixture Libraries. You will see the regular libraries. Refer to Image 2 below.
It is probably smart to create a new Library because upgrading or re-installing AccuRender could overwrite these libraries.
So pick Library/ New and give it a name - I’ve picked “XYZ”. Then pick a Folder if you want - I’ve created a new one called “WallMount”, and then pick Fixture/ New - you’ll see a dialog box where you enter the details of your new fitting. Refer to Image 3 below.
Now be careful again here because AR3 will revert to the last directory you accessed not necessarily the new one you want now. Be sure you have the right Library and Folder selected then write in a descriptive name that will mean something to you at some other time in some other project.
NOTE - be sure to check the “Wall Mounted” box. AR3 then knows that this fitting is always to be applied in a vertical orientation (i.e. walls) only.
Materials have been added in the DWG file so we can skip that here.
Now, let’s check our work. Open a new DWG, go to AR3/ Lighting/ Add/ Light Fixture, scroll down to our new directory and there’s our new light fitting. Select it and drop it into the scene to be rendered. Refer to Image 4 below.
The same processes apply to the Test-wbkt2.dwg except that here I have applied a solid plaster material to the diffuser. This obviously means that no light will be emitted except out the open top of the fitting.
Both these fittings have been applied in a demonstration room about 8 ft square. You will see the effects of yellow light being produced from Test-wbkt1 on the right hand wall because of the transparent yellow diffuser we applied. This yellow light may look unpleasant to some people - and it is - the important point is to understand that light passed through a colored object becomes colored itself and will affect everything in the rendered scene.
On the left hand wall the solid plaster diffuser of Test-wbk2 is limiting the light to an upward dispersion only, so you see a strong cone of light up the walls and across the ceiling. Notice that the light appears much more concentrated than the light from Test-wbkt1 although both are emitting the same total quantity of light. Refer to Image 5 below.
This completes the tutorial.
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