Join Adam Crespi for an in-depth discussion in this video Laying out form ties and joints, part of 3D Textures: Formed Concrete.
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- [Voiceover] Concrete is a timeless and ancient building material. The Pantheon in Rome is built of concrete and still stands as one of the largest unreinforced concrete domes around. Concrete is actually a combination of portland cement or modern concrete anyway. And aggregates, sand and stones, and water to cause the chemical reaction that actually binds it all together. Concrete is the most used building material around by weight and probably by mass as well. It takes on many forms, and that's the really neat thing.
We can cast it into whatever we want. If we can dream of how to form it, we can make it. So look at the Pantheon for example. We get Tadao Ando's Church of the Light. A seminole work in concrete. A bare concrete volume done in exquisitely smooth form work. Really celebrating the flush detailing of that concrete. And the smoothness of it. There's the Salk Institute, by Louis Kahn. This one is known for, not only being of concrete, but the interplay between the concrete and the wood fill.
And also, the patterning of that concrete on those walls. Where the concrete casting itself becomes the ornament. When we're making our, perhaps more mundane structures, our concrete walls for office buildings and so on. We need to think about what are we doing and where is it going to be. And also is there decoration from the form marks and form ties. Concrete as we know is heavy. And so what we do is we tie the forms together through themselves. Form ties that tie the size of the form in and keep them from blowing out as that concrete hardens.
They can then be snapped off. And as we can see in this image for example. They give us a discrete pattern in there that we can treat as part of the design if we want. We're going to work in SiteCast Concrete, which is different than precast which is made in a factory. SiteCast again, can take any form out there. From the ornate forms of Frank Lloyd Wright to the very organic sculpture. To the common place, a simple concrete floor and columns for example. Or even a waffle slab or something similar. When combined with steel reinforcing, concrete can take on almost anything we want to build.
And we'll look at how to draw that texture for our concrete, with those form ties precisely placed in Photoshop. So we can have whatever concrete, however big we need. I'm here in Adobe Photoshop. And what I'm going to do is make a new document. Choosing file and new, and starting out at two K square. I'm running an RGB image at 72 pixels per inch in 8 bit color. And at the moment sticking with the sRGB color profile. If you are color managing, now is a good time to put a profile in. Such as rec709 for example.
I'll click okay. And what I'm going to do first with my concrete, is establish the grid pattern and form ties. Not the modeled appearance of the concrete yet, but really the structure of the forms on here. So that we establish that regularity of our paneling. I'll start out by pressing M, and I'll switch over to a rectangular marquee. In my rectangular marquee, I've set the size here as a fixed size. Running at 1024 by 512. So I'll end up in my two K square image with eight rectangular concrete, well shapes.
These will be, let's say four by eight feet, or three by six. Something in that range. What I'll do is land that marquee anywhere but not an edge. And then make a new layer. I'll take this marquee then and zoom in to see it. And I'm going to stroke it in a couple of pixels. First, I'll set my foreground color to kind of a medium dark. Maybe a brightness around 30 or so. Press M for marquee. Right click and stroke that marquee. I'll stroke it with a two pixel width on the inside.
And click okay. And this gives me a dark line around the inside of it. Then I'll change that foreground color to be a bit lighter. Maybe around 50% give or take. And reduce the size of that marquee. I'll choose select, modify, and contract. I'll contract the selection by one pixel. And in this case, because I'm running the latest edition of Photoshop, I have the option to apply the effect at the canvas bounds. If you're running a slightly older version, you may not have this option.
And that's why we stick that marquee somewhere in the middle of the document. So it contracts equally on all sides. I'll contract in by a pixel and then right click and stroke that marquee one pixel wide on the inside. Now what we've got, pressing control D to D, select, and zooming in as well, a two pixel line from dark to light on the outside. So when we mash these together, we'll see light to dark to light subtle grooves in our concrete. Not necessarily a giant cam for a reveal.
But a slight indent between each panel. Maybe the panels are metal or plywood with a small spine between or something like that. And this gives us a little bit of panelization. And also helps us tile the texture cleanly. I'll zoom out by pressing control 0, and now make my form tie plugs. Form ties actually tie the forms together. Again, so they don't blow out while the concrete is curing. They are then snapped off and plugged with lead or plastic or something similar. Resulting in a flat recessed disc in our concrete.
I'll make a new layer. Zoom in again, switch over to my marquee and choose an elliptical marquee. I'll start out with a decent size marquee. What I'll typically do is land a marquee in. Let's say a 64 square. And do a quick visual assessment. At the moment that's too big. That's the size of a pipe running through that concrete. A standpipe or something similar? So what I need to do is to downsize this marquee. I'll try it at, let's say 48 square.
Land that marquee again. And now I'm going to make my form tie. And again, this is still too big. But I'd rather draw big and reduce to get a little better blending and color. I'll press G for gradient. Which you can fly out under the paint bucket if you need. Then, I'll click on my gradient and edit it. What I've done here, is to configure this gradient to be, basically flat for about half of it. And then wrap up to a lighter color. Our form ties then recess towards the center and then go flat.
So this is really going to help me get that form tie contour in. What I'm going to do is to add in another gradient key in here. I'll make it a little bit lighter. Maybe a brightness in the, let's say 45 range or 50. Now what I've got, and I'll take that gradient key and slide it all the way over to the right, is a slope down and then in here, and I'll try to stop landing gradient keys and just grab that midpoint. A nice slope down and a sharp edge down to flat. So when I make a normal map from this, because it's a grey scale after all I can convert.
I've got high sloping down to low, dropping down quickly to low. And then a flat middle. Again I'll press G for gradient. And I've set my gradient to be a radial gradient. Which we can do up here at the top. I'll click in the center. Typically you'd think okay, let's hold shift and drag out to the edge. But that doesn't give us quite the right shape. What I'm going to do is make sure, one, that I land as centered as possible. And two, go a little bit farther out.
To make sure I really catch that white all the way out there. I'll deselect by pressing control D and there's the initial height map or bump for that form tie. Now, when we zoom out, we can see it's still too big. But the shape and color, or rather value are right. So I'll zoom in and I'll downsize this by pressing control T. And I'm going to reduce down by 50%. I'll make sure that width and height are constrained, and I'll put in here, a width of 50.
I'll press enter to accept the transformation and zoom out to check again. That's pretty good. What we're seeing in here are concrete. Let's say it's six or eight feet long and a decent sized form tie in there. Now what I'll do, is just snap this in place. I'm using the new smart guides in Photoshop here. I'll snap it into the corner and then pull it down holding shift and looking at the change here on the X and Y. I'll pull this one in by 100 or so. Well there's 108, that's good enough.
Then I'll Alt clone it down. I'll bring it down and pull it back up again by that same distance. It's okay if you're off a pixel or two. It's really about that regularity of pattern, as close as the form makers could make it. I'll tab back in my menus and pick both of my layer two's. And I'll clone them over. Holding Alt and dragging. What I like to do is to land it on the side here and then pull these layers back in. Again, here's our measurement of 108.
And then I'll put in some in the middle. For these, you can either measure it exactly, holding shift to constrain on the horizontal or using the smart guides. Or eyeball it in place. Here's just about 256, and again, just about 256. It's so close we won't notice the difference. But it's regular enough to believe it was precisely placed. Now what I'll do is clone this around. I'll take all of my layer two's and mash them down.
Selecting them and pressing control E to merge those selected layers. Then I'll take layer one and layer two copy, whatever it is. And snap them up to the top corner of the document. And then Alt clone them down or across to fill in. And I'm looking at that change there. Zero on the horizontal and 512 on the vertical, to make sure that I'm spaced properly. I'll clone down. And then finally, take all these layers and clone them over.
I'll pull them over here, and there's 1024 on the horizontal. So I've got a perfect match. Now it's not the right color for concrete, and still too light around those form ties. But what I've established here is the pattern we expect to see. That in this case, whoever the architect or designer was, specified the form ties at this regular pattern within those stack upon panels. So that they become the ornament on this concrete wall. That's what we look for in this texture. Where we expect to see regular, we find regular.
Now, I'll do a little bit of layer management. I'll select all of my layer two's, and merge them. Pressing control E to merge the selected. Then I'll do the same with layer one. So this way, I've got my edges and my form ties cleanly separated. Here's the final step then. We can rename that layer two to form ties. And set it's blending mode to multiply.
This way the white or light grey disappears. What we get more properly when we zoom in is this. It's a nice dark gradient, graduating down to a flat deep grey. And this will become our form tie in here. Where we have in our normal map, a slope down to a flat spot. Where those form ties are slightly recessed in that concrete. Now we're ready for color. The trick as with many textures, establish the pattern language before you work on the varied detail.
Make sure that, what we expect to see is there. And then you can put the art into it.
Interested in creating other kinds of textures, such as wood grain or metal? Check out other courses in our Creating Textures series.
- Laying out form ties and joints
- Painting the base color and variation
- Adding bubble holes and voids
- Adding color variation using custom brushes
- Drawing exposed aggregate sections
- Creating a poured concrete material
- Mapping the concrete to flow around walls