Tuesday Tutorial: Time to get your hands dirty

25 05 2010

Dirt is one material that, while rarely fully exposed, is often a base material that other elements are placed over.  Many times these elements will have gaps between them where there is exposed dirt, whether it be in a mulch-less planting bed, or in areas like a dense forest as we have here.  You cold also combine the dirt with another layer of material, like a scattered moss or leaf-litter, to add some depth and realism.  I have used this in 3D models before with good results, but in a 2D rendering it can add slightly more detail than is useful, creating a cluttered look that makes the drawing a little harder to read.


The first process for making dirt is essentially identical to how you make turf.  However, the images I selected for this tutorial have some major imperfections that will allow me to show one of the powerful tools in the Photoshop box: spot heal.


You can see here that the first image I am using, from a residential lot, has a large pipe with a string attached that sits in an area that otherwise I would want to use.  I could give up, and use a different image, or only use a small section.  I did not take the photos intending on using them for this purpose, and therefore only had a few, and I also was only using a small piece from my second image due to the angle and size of the bluestone patio in the image.

As I need some flexibility in size to reduce the tiled look, I opted for the slightly more challenging method of healing the pole and string out of the image.  First, however, I adjusted the perspective of the image to minimize scale changes throughout the dirt.

Once I did that, I was able to use my heal brush to remove the pole from the image.  In an image such as this, it involves a relatively simple process.  First, select the spot heal tool from the main drawing toolbar.

For an image such as this, its best to use the spot heal tool instead of the heal tool.  Heal is better when large areas need to be covered using techniques I will cover later in the series.  The spot heal tool works by essentially blurring the area.  To demonstrate the basic idea, I created a colored grid.

I then used the spot heal tool on the path seen in purple:

This is the result:

So by using this tool, and painting over the pipe and string, you are able to essentially eliminate them from the drawing with very little work, and you now have a much larger area to pull your texture from.

Next you have to pull an area out to use as your pattern.

As you can see, there are some areas in the bottom of the drawing that are much lighter than the rest of the dirt, so you should again use a burn layer and around 8-9% opacity black to paint the areas darker.

This light amount of paint evens out the textures greatly, giving a pattern that will look fairly uniform on its own.

Once you have that, it’s the same method of setting up two buffer areas with guidelines, copying them, erasing them, and then cropping the image down to creating tiles without hard edges.

This material looks pretty good, but when rendered it will likely look a little to cool and dark, almost like rough asphalt.  By shifting the image’s saturation, you can get an image that it warmer and a bit lighter.

I took the same steps with the second image, giving me a second, smaller texture that is equal in quality to the first.

By layering these images in the same way as I did with the turf textures, and with the same masking layer pattern, you get a seamless topsoil layer.

Next week, we will tackle the granite outcropping on the west of the site.





Tuesday Tutorial: Turf, and basic techniques

18 05 2010

As it is with many things, my technique for turf, and the similar techniques I use for other materials, were born of other needs.  Namely, I hated the way my turf looked in 3D renderings.  You could use a created texture, but it never looked organic.  You could use a photo, but you got TERRIBLE tiling effects.  You could do a slight color overlay to soften the impact of the tiling, but the color was always off, and you would lose to much of the internal texture.  I tried all of these, before scouring through tutorial sites and stumbled on the idea of using two separate textures, with a masking layer to blend the two.  This is used commonly in 3D models when you have to put a non-square image onto a model.

Say you have a beer… sorry I got distracted there for a second.  So, you have a bottle shaped model, and you want it to be beer.  The first thing you will do might be to fill the bottle with liquid, and make the material into tinted glass.  You then have a very pretty blank beer bottle.  It needs a label to look right.  Many beer labels are not square, but no matter what the image you import onto the model will be square.  You handle this by making two images.  One is the image you want shown, the other is a mask, like we make for the hand drawn lines- with what you want shown in white, and what you want to have invisible in black.  Now, you normally just place a single image, so you get one label.  But there is no reason you couldn’t tile the material so it would repeat hundreds of times over an open field. And there is no reason this technique cannot be used in photoshop to make detailed, photograph based textured that don’t show any tiling.

The best way to get good, organic texture, and realistic color, is by using photos.  These can be photos you took expressly for texturing, or everyday photos that have a good amount of the material you are looking for.  The best option is images takes specifically for texturing, as you can take a picture that will be fairly evenly lit, and taken from above, reducing the amount of perspective in the image.  For this tutorial I am using two photos I took of a small residential project I designed last summer:

The first thing you do is crop the non-grass areas out of the image, so you have a decent base to work off of.

This gives you a clear area of turf to work with.  Having other distracting elements removed from the photo also allows you to see inconsistencies in color.  These inconsistencies will show clearly when tiled.

Looking at the image, you can see how much lighter and smaller the blades of grass are on the top and right of the image.  By cropping those areas out you easily eliminate some trouble spots without resorting to the slower techniques next.

There is still a darker area to the left of the image.  The way I will address that is by adding a second layer above the turf image.

By setting the layer to linear burn, and using a round, soft brush, set to black, with around 8% opacity, you are able to paint the image slightly darker in the areas that need it to even out the over all texture.  By using linear burn you darken the tone of the image without adding gray to it, muting the color and texture.

That is all the paint I needed to lay down to change the texture to this:

The image is a little more flat then i would like, so next I increased the contrast to give more sharpness to the texture itself.

As you can see, much of this process is trial and error- looking until you see a problem, fixing it, then looking for the next problem.  After doing all these adjustments, I noticed that the perspective makes the foreground far more coarse than the top of frame.  To fix this, I used Edit->Transform->Perspective to both shrink the foreground.

Once cropped, you have a nice smooth texture that still has a realistic amount of character.

This seems like a fairly regular texture, with a good amount of color, so its time to make the image tile without a hard edge that will always show clearly.  The first step is to lay some guidelines around 1/10th of the way from the edges.

Select the areas between the edge and the guidelines and the outer edge, and copy it on a new layer to the opposite side.  This makes it so you have a smooth transition from the left side to the right, with no edge.

You will still have hard edges where the new layer hits the old, but you can now make a transition between the two.  For this tutorial I used the most basic method, with is to use a soft eraser to fade the transition layer from the edge in.

Now by cropping down the image to where you have the guidelines you will make a tile that will not have a hard edge.

Now with a smother transition, preventing a hard edge your ready to make a pattern.  Hit Ctrl+A to select all, then go to Edit->Define Pattern and name your new pattern (Something like Turf Layer 1V1.0) and save the image in a folder- mine are saved to the desktop->Render Patterns->Turf->Turf1V10.jpg.

This way you can back up all our render patterns, and move them to other computers just by opening the image, and defining the pattern again.  Now give your new pattern a shot, using it to fill the turf areas in whatever rendering you are working on.

Now you repeat the same steps with the second image.

Crop

Burn

Perspective (correct for off-center image here as well)

Crop and increase contrast, copy edges and erase to eliminate straight edges

This is a key point in the creation of your second pattern. To make an organic, non-repeating pattern, you must make sure the two final patterns sizes will not allow them to line up often, creating a repeating overlap.  You do this by looking first at the size of your first pattern.  My layer one is 280×224.  That means you will have an edge (left to right) at 0,280,560,840,1120,1400 etc, and (top to bottom) at 0,224,448,672,896,1120 etc.  You want to pick sizes for your second layer that will not line up with those.  I resized mine to 600×415.  That means that left to right my two tiles will not repeat until 4200, and top to bottom until 92960.

Once you resize your pattern, save it and make it into a pattern just as you did with layer 1. And paste it as a second layer in the same rendering.

The last step is to create a clipping layer, which acts basically like a masking layer, for the grass layers that will allow the two patterns to mix. First pick a noisy, random pattern brush.

Then go into the settings for the brush, and max out the size jitter, and turn off the brush presets other than Shape Dynamics, Scattering, and Smoothing.

Then turn up the scattering, and turn the count as low as you can.

Now make a new image, and make a second layer in the image.  Make a scattered spray of black over the second layer, getting fairly even, but random coverage, then turn off the background layer.

Use the same method of Guidelines, Copy, Erase to reduce edges, than use the same idea as above to resize the image to reduce overlap of the edges.  Last save the image as a PSD (to preserve transparency), and with the background layer off, make the image into a pattern (Turf Mask v1.0).  Spray the mask into the same area as you had the turf, into a new layer.

Put all the layers into a Turf folder in Photoshop, with the mask sandwiched between the two turf pattern layers.

Now select the top-most turf layer, and click on Layer->Create Clipping Mask

This will tell the selected layer to be masked by the layer behind it.  This mask is not based on Black Vs. White, but opacity, which is why you had to make the background transparent for your masking pattern.

This finally gives you the final results you have been looking for:

A smooth, lineless, textured, natural colored pattern.  You can also look at the overall image here, and – using hue-saturation/contrast – tweak the colors until it looks a little better (This seems a tad brown and muted to me).  Write down what tweaks you made, reopen the saved patterns you made, and make the same tweaks, save the version 2.0 of each, and re-define the patterns as well.

These two patterns don’t seem like they would work together with the different darkness levels, but they are what gives you the following results:

While this process is time consuming and a pain, the key is to remember that from now on, all you have to do is paint an area with three patterns, make one a clipping mask, and your done.

Tune in next week for the next key landscape building block: dirt.





Tuesday Tutorial Re-boot: To line or not to line

11 05 2010

When starting a digital rendering, just like with a hand rendering, the first step is always to create the lines you are going to render within.  Generally people use lines directly taken from AutoCAD for digital renderings as these are the “cleanest” lines, and allow for some shortcuts such as exporting each area as its own file.

This method, which I have used often, involves turning every layer off except 2 – one framing the layout window, and one with a single rendered material (turf, pool edging, brick patio, etc.) You repeat this with every material, then bring them into Photoshop, and create a single drawing with the different areas as layers.  The advantage is that you then can use the magic wand to select even the most complex shape in a single click, regardless of how it will intersect other layers.

The end product is a clean rendering that has good line-weight, and reads easily.  The problem is you also have a drawing that has perfectly straight black lines, which add neither realism or soul to the rendering.

The second method is to forgo lines altogether.  Use the method described above, but turn all the cad layers off before saving (and make sure you selected both the area inside the lines, and the lines themselves to insure there are no gaps in your rendering).  This moves you a step more natural, as you have slightly blurred edges between materials, making a more aerial-photographic look to the rendering.  This may serve well in certain presentation settings (when trying to show the design blending in with existing conditions for instance), but the lack of hard lines, and of line-weight, greatly reduce the readability of the design.

In general, I prefer a third method that is less efficient, but gives – in my opinion – far better results than either of the other methods.  This involves printing out your full design, doing the line-work by hand, and then scanning it in to render from.  This involves a few levels of added difficulty, as to have a single person render they need to be equally skilled with Photoshop and a pen, a large-scale scanner is nearly a must, and there is another time-consuming step added to the process.   The added style, in terms of having a drawing that reads well AND has soul, more than outweighs the challenges in my book.

I said a large-scale scanner is nearly a must because it can be done with a traditional 8.5 x 11 scanner, but the line work must be far more precise, and line-weights are much harder to balance at a small-scale.  (I am using a small scanner for this project, and a .1 with a straightedge is significantly thinner than a .05 freehand drawing lines less than half an inch in length.)  Some of this may be due to the fact that I am slightly out of practice on my hand rendering, but some is also the difficulty of small-scale work.

One thing I like to do to simplify the process is to first draw the ground plane with just material borders, scan that, and then fill in any detail (line hatching for decks/paving if desired, or, in this drawing, the flagstones), and rescan the whole drawing.

This has two main advantages.  First, it allows you to still color as a block, and then add the detail later, when it doesn’t slow the rest of your work.  Second, it allows you to tweak the line-weight on those detail lines.  This may play a role even when working with a large format scanner, but it is a lifesaver when working small format.

This way you can, after cleaning up the scans and making the white areas transparent, you can delete the outer edges of the detailed scan’s lines, reducing the line-weight, and increasing readability.

One of the tricky parts of this process is how to make the black lines the only thing on a layer, so you can render behind it and have the black lines not edges with a light gray halo.  The first way you can do it is by selecting the white areas, deleting them, and darkening the other areas.  This can often lead to white/gray artifacts in the black lines.  The better way is to use masks/alpha layers.  First we have the scanned image:

The first thing that needs to be done is cleaning up the white areas.  The easiest way to do this, along with darkening the lines, is by increasing the contrast of the image.

Once you have a sharp black line on white, go to Image->adjustment->invert.  this will give you a negative image, with what was black white, and what was white black.  Then go to Image->Adjustment->Hue/Saturation and desaturate the image.

This step is necessary to make it into a masking layer, and it also allows you to more easily see areas where the black lines (now white) are slightly gray and transparent.  You can now tell if you need to up the contrast even more.  Then make an additional layer of solid black.  Open the masks window by going to Windows->Masks, and click on the icon for “Add a Pixel Mask”.

Select your inverted layer, Hit CTRL+A to select all, and CTRL+C to copy the image.  Then select your black layer that now has a masking image (Shown with a white box in the Layers palette).  The way to paste info into you mask layer is by clicking on the Channels tab of the layers palette.  At the bottom of the list you will see a layer that is not active and is pure white.  Turn on and select the layer, then hit CTRL+V to paste your image data.

By turning off the masking/alpha layer, you now have a layer that is pure black with transparency for your textures to shine through.

The only remaining thing is that if you do need to edit the layer, you don’t edit the black layer, you go into the channels, turn off the RGB layers, and turn on the masking layer.

Then you edit this layer.  So if you need to delete a line, delete it here, or paint over it in black here.  This is also where you will thin your detail lines if you need to create more line-weight.  The easiest way to do this is by using the magic wand with “contiguous” unchecked.  Then go to Select->Modify->Expand.  A little trial and error is needed here to find the right amount to reduce the line-weight without erasing them.  Once you have the right amount of expansion, make sure black is your background color, and hit delete to reduce the line-weight.  If you’re my method of a main line layer and a detail line layer, each will be set up this way, in one folder on the top of the layer stack.

Next time I’ll go over turf, and give the technique I use to erase the tiled look patterns normally create.





Tutorial Tuesday- Reluanching May 11th with this gem!

4 05 2010

After about a week and a half of fine tuning techniques, taking tens of photos for reference use, and taking hundreds of screen shots, my relaunch of Tutorial Tuesday is imminent.  This time, I am adding a twist to the formula.  Last year, I came up with the idea of doing the tutorials based on a single project, and walking you through my process.  This started with my SketchUp models.  Unfortunately, soon after I began making the project model, intended to be a base for a new website, I decided to go in a different direction.  However, starting next week, you will get a step by step walk-through of how I went from this:

to THIS:

As always, I am looking for feedback not only on my method of tutorials, but also the content and end results of my methods.  I am making these tutorials so people will have the jumping off point that I never had.  I want people to find new techniques, grow what I do.  I have spent countless hours growing these methods, all I ask from you in return is that you spend a few hours developing ways to improve these techniques, and let me, and the other readers, know what you did.

With that, I’ll see you next week!