Lap Siding and Baked On Shadows

In my previous post, I wrote about the creation of a simple rendering. Or really I talked about incorporating existing conditions to improve a basic rendering. The focus was on site context—location, time, and also the viewer/client. But there was one other piece of existing information I used: the siding. From the initial meeting with the client, we knew that the siding of the new garage was going to match that of the existing house. So from the first moment they saw images of the project, they were looking at renderings and 3D views with the existing siding. Here’s how important that piece of data is. Below are two images, both screen shots of the model. The first image shows the model with three-dimensional lap siding and a Surface that is defined by a simple color in ARCHICAD. The second image is a screen shot of the same view but with an improved texture for the siding’s Surface.

Surface with color

A simple Surface

Surface with image

An image based Surface

The difference is extreme. And neither image is a rendering, just a view of the model from the 3D window—a view you can navigate and work in either at your desk or during a meeting. Of course there are other reasons why the 3D window looks so nice in both images. If your 3D window isn’t looking as good, read this post for how to up the default quality.

If we do a quick rendering, we end up with something even nicer. I don’t need to share the rendering to prove the point I’m trying to make in this article. I’m just showboating. But it’s for a purpose. Renderings are so fast and easy now that we have the CineRender engine. As ARCHICAD users, we need to start thinking of renderings like we do sections and elevations: documentation we do without thinking, documentation we create whenever we want, where ever in the model we need them. Not sure how something will look? Do a rendering! Curious what the shadows will be at a certain time? Do a rendering! Want to show off your project to your client? Do a rendering! Worried that your Facebook page or Twitter feed is slow? Do a rendering! Imagine creating one fast rendering a day for a year. Think about how much great content you’d create. And how much you’d learn. Okay. Tangent over. Here’s the same view but rendered:

Surface with image rendered

Rendering makes it even nicer

There are a few things happening here. The most obvious is that a homogeneous surface is dull. In real life, no surface is perfectly uniform. Using a Surface with variation and texture adds realism to the image—both in the 3D window and when rendered. Realism is perhaps the wrong word. The textured surface makes the image less cartoon-y. The goal here, especially in the 3D window, isn’t realism. It’s communication, believability, and invisibility. You want the textures to convey intent and then disappear. You want to minimize distractions. The solid color only conveys half of the final product. Using a texture gives the 3D view more physicality.

The other primary shift between the two images are the shadows. The shadows in the second image are much better. Why? Because the image combines shadows cast by ARCHICAD and baked on shadows that are a part of the image attached to the Surface. If you look at the rendering, the improved shadows are even more pronounced. The baked on shadows add more depth to the siding. And I think that accentuation is a good thing. Below is a basic tutorial on how to create a Surface with baked on shadows cast by a repetitive element and add it to your model to create the second image. My previous blog post will then help you get to image three, the rendering.

But First How to Make Great Lap Siding in ARCHICAD

To create an image like the one I shared above, we need to create both the lap siding as 3D modeled elements and a pretty Surface. I mostly want to talk about the Surface creation, but to understand why I am creating the Surface the way I am, I need to cover how I do the siding. Fortunately, I’ve already talked about my siding techniques before. To model the lap siding, I use the standard Complex Profile Siding trick. If you are already modeling siding with Complex Profiles, you can skip ahead. If you aren’t modeling your siding, you should be. Here’s a blog post about that. And here’s the accompanying video:

There are many benefits to using three dimensional siding; whether you are showing a rendering, looking at the model in 3D, doing quantity take-offs, showing an elevation, or any of a number of other things, modeled siding is wonderful. In 2D, modeled siding gives a nice contour to the edge of a building. The shadows caused by subtle changes in the surface add readability to the drawings and also help obviate the compulsion to worry about line weights in elevation. Plus look at the image below: isn’t that shadow of the light fixture changing with the slope of the siding just perfectly beautiful? Shadows in elevation

I could go on and on about the value of modeling siding—it’s going to be built, has dimensional repercussions, and matters, so why wouldn’t you model it, always?—but let’s just focus on shadows. Shadows in 3D caused by modeled siding adds depth to the images. But I’ve found we can push that expression further by using both ARCHICAD cast shadows and baked on shadows. What are baked on shadows? Shadows that are part of the Surface. There are a limited number of locations where this works, but when it does, it’s awesome. Primarily, I add baked on shadows with lap siding. To create Surfaces with baked on shadows, it’s best to start with a photo of the thing you’re hoping to model.

  1. I took a photo of the existing siding (this could also just be a photo you find on the Internet). I did my best to make the photo as flat and straight on as possible. But I didn’t stress about it being perfect, because we can fix that in the computer.Siding - step 1
  2. I isolated the part of the photo I wanted to use and fixed the distortion in GIMP (though you could use Photoshop or any other image manipulation software). I fixed the distortion before I isolated the portion of the photo I would eventually use. I made sure to grab a large enough section of the image to minimize the appearance of a pattern when it is applied in ARCHICAD. I chose two rows of siding rather than three or more because two gives me the right balance of variability and control. If you use more than two rows of siding, you might struggle to align your texture to your model—as your model is probably more perfect than the image is. In the image below I spent a little time during the cropping process to make sure both rows were the same height. If you want to use more than two rows, it’ll just require a little more processing to make sure they are uniform in height. Not hard, but not as easy as using two rows. When I clipped the image, I made sure the bottom left hand corner of the image would line up with a clickable point in my ARCHICAD model. Once this image is in ARCHICAD and linked to a Surface, I’ll be applying that Surface to a Building Material and/or element. I will then need to move the Surface using Align 3D Texture to make sure it fits properly with the model. So I want the start of the image to be something I can work with. This is why the image goes shadow, siding, shadow, siding, rather than have the shadow at the bottom: I can use Align 3D Texture and set the start of the texture/Surface to be the bottom inside corner of the siding (where one piece of lap siding touches another). It’s a known known. Siding - Step 2
  3. Once I get my image perfectly orthogonal and cropped, I further cleaned up the image and made sure that when it was mirrored, it didn’t look tiled. If you look VERY closely, you’ll notice that I mirrored the image so that it’s edges are now identical. There will be no seam when this image is tiled. During this stage you can use mirroring and other tricks to make the base image longer, turning a short segment of siding/image into something much bigger. During this phase, I also spent some time to remove other noticeable irregularities. By removing noticeable quarks in the image, I further decreased the danger of obvious tiling. These subtle changes are most noticeable if you look at the shadows. There is one outcropping of shadow in the previous image that is super obvious and would be very ugly repeated across an entire building—even if that building is a tiny garage.Siding - Step 3.jpb
  4. Finally, I corrected the color in the photo to remove the reddish hue The real siding is much grayer than my photo shows, so I fixed that. If you look back at my images, you’ll see that the red returns in the rendering because of the sunlight (which is why it was there in the first place, so that’s a cool verification of how the sun works in ARCHICAD). For some of my renderings, I did a little post-processing to remove the red again. While the warmer color is more accurate, I wanted the rendering to better represent the paint as it’d be seen in the can (or on a cloudy day) rather than in bright sun—even though I wanted to do the rendering on a happy, clear day.Siding - Step 4

It’s worth stressing that none of the image manipulation was that complex. I am not an expert in Photoshop or GIMP. People fly me around to talk about ARCHICAD, not those other programs. So what I’m doing should be easy for anyone to tackle. And I’m sure there are smarter ways to do it. But my solution is fast and good enough for a non-expert like myself.

Once you have the image corrected and saved, it’s time to import it into ARCHICAD. Embed the image in your file or place it in a linked Library. Then add it to a new or existing Surface in ARCHICAD. I suggest starting with an existing lap siding Surface (or whatever Surface you are creating). It’s easiest to add the image to the OpenGL Settings. Remember to scale your image based on the total perimeter between points on your siding, not just the vertical dimension. The trick is to make sure the image stretches to include the slope of the siding and the return. So if you have 6″ lap siding, your two board image won’t be 12″, it’ll be more like 12 1/2″ because the image is stretched across the entire surface area of the siding, not just the vertical surface when you are looking at an elevation.

6 inch lap siding is not 6 inchesIn the image below my lap siding is 13″ vertically but the image needed to be stretched to include the 1/2″ extra of horizontal dimension in my Complex Profile (13″ + 1/2″ + 13″ + 1/2″ = 27″). You’ll probably set the vertical dimension, align the texture in the model, and spend some time finessing the exact scale and starting point of the Surface. Setting the horizontal dimension of the image is much looser than the vertical dimension. I recommend unchecking Keep Original Proportion and playing with the distortion. You might find stretching or squishing the image horizontally will improve the feel of the model by making the repetition of the image less visible. Also if you distort the image horizontally, you might be able to better suggest the essence of the material—maybe stretching the siding by 500% will make it feel more like the real siding because the variations in the texture take on a new quality. Or maybe not. Play around and see what feels better.Surface Settings - Internal Engine

Once you’ve added the image to the Internal Engine / OpenGL settings, switch over to the CineRender settings and select Match Settings/Update CineRender Settings (from Internal). This will get your CineRender settings to an adequate spot where they show all the hard work you just did to create an acceptable image. Of course this is just the beginning. If you want to get into more detail, then you can mess with all the other settings CineRender has to offer. But just doing this will improve your 3D window and basic renderings so much.

Surface Settings - CineRender

With the Surface complete, link it to a Building Material and make sure that Building Material is assigned to your Complex Profile siding. Here’s another instance of how great Building Materials are. By linking the Surface you’ve created to a siding Building Material, you can universally apply your efforts to all the siding in your project. If you have multiple siding types, you need to either create multiple Building Materials or override the Surface of the placed elements. There’s no immutable rule for making that decision. You’ll have to make that on a case by case basis. I’m not even sure I have a rule of thumb to suggest. If you have two types of siding I can see just as many arguments for overriding the Surface of one or both or for making unique siding Building Materials. Maybe we can discuss that in the comments.

Siding BMatNot every project has lap siding, but these techniques are valuable for all sorts of other things. A variation of the image manipulation would be useful for creating various roofing materials (standing seam for instance). The lessons give clues on how to handle siding that is predominantly vertical—I’ll record a video on that soon, though maybe not until after the new year. Most importantly though, these sorts of solutions help push your models ever deeper into BIM. Because remember, not only does this give you better renderings, it’s also embedding more data into your model (what the siding really will be), providing better communication, teaching you to look for more clues at the site, reminding you to thinking about ethereal things like shadows, helping you shift the conversation from general to specific while not getting trapped by realism…

One post article comment: much (all) of this variation in Surface texture can be created natively using the CineRender settings. But that isn’t what this article is about. Are you following GRAPHISOFT North America on Twitter? Click Here to keep track of all the latest ARCHICAD News in North America (and beyond).


  1. Todd Hotchkiss

    When siding is part of a complex profile, that has multiple surfaces, does Align 3D texture work? I’ve had that problem before.

    • Jared Banks

      I haven’t had any issues. But I can see where problems would arise as the align 3D texture would affect all surfaces. So if your wall had an interior and an exterior surface pattern, both would be aligned by the method described in my article—which could cause trouble. The solution would be to make sure there isn’t a texture on more than one side of the element that needs aligning.

      I’m working on a project right now that might run into this issue. I’ll report back.

  2. Kieran

    This process outlined is called Baking textures and is a great way of utilising textures to add detail.

    If you have a material for your siding that has no shadow you can isolate a section of the siding and set up an orthagonal Side View Camera and render it with shadows on, also you can turn on ambient occlusion. You can then get that render in photoshop and put it over the original texture and get the correct proportions and save. Simply update your libraries and you have a baked texture.

    I would use baked textures on buildings that are context and in the background, so that they are low poly but at a quick glance provide a lot of detail. You can create whole facades as a surface and then apply it to a low detail morph and add a lot of background detail to a project

  3. Rebel

    Nice method. I have a question, why can’t you use Custom wall Profile at once and use it with windows that installed once instead of using empty window hole and windows? What is the reason you don’t use that Custom Wall Profile instead of adding Exterior Wall to wrap it around the building? I m still learning about this profile manager as along as I am trying to figure out because of first floor and second floor siding has been issue dues to height various that cannot be cooperate to keep all the siding uniformity. Usually when you have all the stories, you want the siding keep all evenly all the way up to roof. Not separate for each one. I am still figure this out. Thank you for sharing this idea but I wonder why you had to do this way. At first when I saw this, I thought it was kind of time consuming but I cannot figure out why you had to do this. Hope you can tell me the reason why so I can compare the difference between single Siding custom from Profile Manager and whole “Custom Wall Profile” from Wall Setting.

    • Jared Banks

      This blog post and video will explain a bit more:

      There are many reasons:
      1) using a complex profile as your primary stud walls becomes much more complicated as you’ll quickly find that you need multiple complex profiles for different conditions. So it’s not a choice between one complex profile for stud + siding vs one composite wall and one complex profile wall. My solution is almost always easier to manage. Think about it this way: if you have a 2×6 exterior wall and a 2×4 exterior wall (say main house vs garage), then you’d need 2 complex profiles to manage, at a minimum. It gets very messy, very fast. Now imagine your siding changes above or below windows. Or switches partway along a wall.
      2) by keeping the siding and the framing wall separate, you are working with two simple sets of walls: composite walls that act normally and siding walls that are just about siding.
      3) by keeping the siding separate from the framing wall you don’t have to worry about siding changes vertically or horizontally. The siding can ignore whatever is going on behind it.
      4) from a time management standpoint: it’s really not time consuming once it’s set up. But like any templated work, the extra effort at the front end more than pays off for itself over the life of the project.
      5) windows and doors sometimes have issues with where they sit in a wall; and complex profiles with a lot of ins and outs sometimes have issues at corners when they connect with walls they aren’t perfectly aligned with. Typically these issues can be easily resolved. But all it takes is for one connect to not be fixable for the entire wall as complex profile technique to fail because of one awkward connection.

      In other words, separating out the siding from the framing wall might be slower to set up but it is much more resilient than any other option I’ve tested.

      Oh and if you ever need to test different siding types, swapping out a 6″ lap siding CP wall for an 8″ lap siding CP or some other option is amazingly easy. Yes you could do that with a merged wall containing both siding and framing, but again with so many other connections to deal with the probability of errors increases.



  1. Obsessed with Sun Studies: Visualization in ARCHICAD - Shoegnome - […] Lap Siding and Baked On Shadows […]

Submit a Comment

Your email address will not be published. Required fields are marked *