Developing the materials
Developing the materials
At some stage in the project you are going to want to export your renders from Revit to complete some post production work, say to replace the background in your render with another image. Fortunately when you export the renders you can save the image in multiple formats, two of which (*.png, *.tif) include alpha channels. This is really useful when you want to change a background image or isolate some geometry.
Internal render saved as *jpg:
Internal render saved as *png:
Internal render with a background photo added in Photoshop using Alpha channels:
I realise the perspective is off but it was the closest photo I had to this camera view. If I had a better photo I could of hidden the tussock grass/sand dunes in this render and shown just the photo through the windows.
If you want to learn the photoshop techniques, click me for link to postproduction page on using alpha channels.
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Materials, materials, materials… time to really start testing some material ideas.
Image credit: Arch Daily, Materialicious, Plataforma Arquitectura.
Lets see what we can get Revit to do, we will start with the strong timber panels varying the colour and texture what I want to achieve is a strong bump map illustrating the separate pieces of timber.
i.e.
My first attempt at creating one of these custom material was quite easy, it was based upon the “Exterior Siding White Horizontal 4-inch” map which I copied, modified the colour balance in Photoshop and saved into the custom materials folder we created earlier. I think this material is quite successful with the exception of the uvw mapping (orientation of the texture map).
So if all of these objects share the same material applied to them how do we adjust the individual uvw maps? What is defining the orientation of the maps on the different geometry? If we open the material and adjust Revit’s equivalent of the uvw mapping what happens?
Well it did rotate the maps by 90 degrees as expected but this is still not what I want. Can you use a single material on a number of objects and individually adjust their uvw mapping?
What part of the geometry is the map perpindicular to by default?
What if we “paint” the material to the surface will the orientation of the map be the same?
Yes. The same material painted to the same geometry has the same mapping.
So what options do we have left now? what about creating mutiple copies of the material and adjust the mapping individually?
Well that works but what a pain in the arse! I had to create four copies of the same material to individually control the mapping, and then guess the rotation for each one and render a bunch of times till I get it right.
Amended render.
Fortunately there is an easier way! Open the material you are working on, under the graphics tab apply a surface pattern, open a view perpendicular to the geometry that includes the material you are creating and using the tab key and left mouse together click multiple times until you select just one of the lines in the surface pattern. You can now rotate, align and move this pattern to suit and the diffuse map that you see when you render moves with it!?
Random yes, but it works and is a lot easier than guessing the rotation for non orthogonal geometry.
Next page: Design options.
