Monthly Archives: April 2016

How to print map graphics as battle maps using free software

11 Replies

You can play Dungeons & Dragons and Pathfinder battles on a sketch, playing on a colorful, printed map raises  your game’s visual appeal.

Many of the artists who draw maps for adventures sell downloadable images of those maps. But these computer graphics never come scaled so that they print with a 1-inch grid sized for miniatures. Even when you solve the scaling, the images can’t fit on a single page from your printer.

Purpose

This post gives procedures for scaling graphic map files so they appear with a 1-inch grid, and then printing the map tiled onto multiple pages.

Contents

This post includes the following sub-procedures:

Before you begin

You must have the free programs GIMP and PosteRazor installed on your PC.

GIMP provides an image editor similar to Adobe Photoshop.

PosteRazor splits graphic files too big for a single page into multiple, printable pages, which you can assemble into a poster-sized map.

Opening the map graphic

To open your map graphic in GIMP, do the following:

1 Click File > Open.
2 In the Open Image dialog box, select the graphic file that will become the backdrop for your battle map, and then click Open.

Scaling an image to print

Battle maps in Dungeons & Dragons and Pathfinder feature a grid of 1-inch squares. To print your map image so each square spans 1-inch, adjust its scale so the image’s dots-per-inch matches its number of dots-per-square.

Start by measuring how many dots now span a square on your map.

Note: If your map image lacks a grid, I’ll explain how to add one in Adding a grid to a map image. For now, this procedure refers to 5-foot plots on your map as squares, even if the lines don’t appear yet.

Measuring the dots-per-square on a map image

To measure the dots-per-square on a map image, do the following:

1 Find two landmarks or marks on the map where you know the distance separating them.

If… Then…
the map includes visible grid Pick two parallel grid lines far apart on the map. Count the squares separating the lines.
the map includes a scale Pick the ends of the scale. Read the distance from the scale.
the map lacks a measure of scale Look for features that can establish a scale.
Example: If the map includes 10-foot wide halls, the distance between walls can serve as a scale.
the map lacks any measurable features Estimate a distance between two landmarks that suits play.
2 Click Tools > Measure.
3 Measure the shortest line between your landmarks.

Click one landmark, press and hold the right mouse button, and then drag to the second landmark.

As you drag, the angle of your line appears at the bottom of the window. When you measure a vertical or horizontal separation, drag a 0° or 90° line.

Release the mouse button.

Result: The distance in pixels appears at the bottom of the window.

scale-measuring
4 Calculate the width of a square in pixels.

If in step 2… Then…
you found a distance in squares Divide the measurement in pixels by the number of squares. The result is the width of each square in pixels.

Example: If you measured 330 pixels between grid lines 6 squares apart, then each square is 55 pixels wide.
you found a distance in feet Divide the measurement in pixels by the number of feet. Multiply this result by 5 to get the width of each square in pixels.

Scaling the map image

Once you know the number of dots per square on your map image, scale the image so its dots-per-inch and matches its dots-per-square.

To scale the image, do the following steps:

1 Divide 10000 by the number of dots per square.

Result: This gives the percent scaling needed to make each square 100 pixels wide.
2 Click Image > Scale Image.
3 In the Scale Image dialog box, set these controls:

  • Set the scaling drop-down menu to %.
  • For Width, enter the percentage calculated in step 1. Height will change to match.
  • Set the X resolution value to 100 pixels/in. Y resolution will change to match.

scale-scale
4 Click Scale.

Result: The image scales so each square becomes 100 pixels wide.

Cropping the map image

Most graphics suitable for battle maps include border areas that you don’t need to print. Remove these unnecessary areas by cropping.

To crop a map graphic, do the following:

1 Click Tools > Transform Tools > Crop.
2 Point the cursor to the upper-right corner of part of the image you want in your map, press and hold the right mouse button, drag the pointer to the lower-left corner of your map, and then release the mouse button.

Result: A rectangle highlights the part of the image that will remain after the crop.
3 If you want to adjust the size of the rectangle, point inside its corners or edges, press and hold the right mouse button, and then drag the edge or corner to its new size.
4 Double click the rectangle.

Result: GIMP trims the image to the rectangle.

If your image already includes a grid, skip the next procedure for adding a grid.

Adding a grid to a map image

If your map image lacks a grid, you can add one.

To add a grid, do the following:

1 If you want your grid to align with a vertical feature such as a wall, measure the distance from left edge of the graphic to the wall.

Click Tools > Measure.

Click on the left edge of the graphic, press and hold the right mouse button, and then drag to wall.

As you drag, the angle of your line appears at the bottom of the window. Drag a 90° line.

Result: The distance in pixels from the top of the graphic to the wall appears at the bottom of the window.
2 Calculate the vertical offset by noting just the 10s digit and the 1s digit measured in step 1.

Example: If you measured 123 pixels between the edge of the graphic and a vertical wall, then the vertical offset is 23 pixels.
3 If you want your grid to align with a horizontal feature, repeat steps 1 and 2 to calculate a horizontal offset, but now measure a 0° line from the top of the graphic to the feature.
4 Click Filters > Render > Pattern > Grid.
5 In the Grid dialog box, set these controls:

  • Enter a Width of 3 px.
  • Enter a horizontal and vertical Spacing of 100 px.
  • If you calculated an offset in steps 1 to 3, click the chain links under the Offset setting, and then enter the calculated offsets.
  • If the map features dark colors and a white or gold grid would be more visible, click the first color box and select a lighter color.

scale-gridClick OK.

Result: A grid appears over the map image.

Saving the map image

To save the map image, do the following:

1 Click File > Export As.
2 Select JPEG image from the drop-down menu.
3 Enter a file name that ends with the .jpg extension.
4 Click Export.

Splitting a graphic file too big for a single page into multiple, tiled pages

Most battle maps won’t fit a single sheet of paper. To print a larger map, you must split it into tiles that can print on separate pages.

To split a graphic file into multiple, tiled pages, run Posterazor and do the following:

1 Open a map image by clicking the open folder icon beside the Input image field, selecting the image file, and then clicking Open.

scale-posterazor-1Click Next.
2 Make the following settings:

  • Select a paper format from the drop-down menu. North America typically uses Letter format, while the rest of the world typically uses DIN A4.
  • Enter 0.3 for all the borders. This values limits the map to the printable area of most printers.

Click Next.

scale-posterazor-2
3 Choose the amount of overlap where two edges of one tile repeat on the next page. Choose from two settings:

  • Setting overlaps of 0 saves paper, but forces you to trim pages exactly to avoid white space or missing map. The lack of overlap at the seams between pages makes your map easier to fold.
  • Setting overlaps of 0.25 lets you make imperfect cuts when you trim the pages, because you can align a cut with the overlapping edge of the next page.

Click Next.

scale-posterazor-3
4 Set a Size in percent of 100, and then click Next.

Hint: Posterazor shows a preview of the graphic with the overlap areas marked in red. Count the number of pages shown in the preview image, and then back up to step 2. Switch the page orientation to Landscape, and then advance back through the procedure. Use whichever page orientation uses the fewest pages.

scale-posterazor-4
5 Click the disk icon under Save the Poster, and then select a filename and location for a PDF version of the map.

Result: Posterazor saves a multi-page PDF version of your map that you can print.

scale-posterazor-5
6 Print the map from your PC’s PDF viewer.
7 Cut the 0.3-inch unprinted edges from your pages and tape them together into a map.

Related

Mike Schley sells his map graphics for many of the current Dungeons & Dragons adventures.

Jarod Blando sells his maps for Out of the Abyss.

NewbieDM explains how to scale maps using PhotoShop.

1981: Adventures at My First Gen Con

7 Replies

In 1981, Dungeons & Dragons was surging in popularity, but you could not tell from my school. When my buddy Mike and I asked our friend Steve whether he wanted to join our next session, he declined. As if warning us of an unzipped fly or of some other mortifying social lapse, he confided, “Some people think that D&D isn’t cool.” Without the athletic prowess of the sportos and too mild for the freaks, Mike and I kept gaming.

The May 1981 issue of Dragon magazine previewed the upcoming Gen Con convention. “The 14th annual Gen Con gathering, to be held on Aug. 13-16, is larger in size and scope than any of its predecessors,” the magazine boasted. “E. Gary Gygax, creator of the AD&D game system, will make other appearances, such as being the central figure or one of the participants in one or more seminars concerning the D&D and AD&D games.”

1979 map of University of Wisconsin-Parkside from 40 Years of Gen Con

1979 map of University of Wisconsin-Parkside from 40 Years of Gen Con

I lived an hour south of the University of Wisconsin-Parkside, the site of Gen Con. For four days in August, this building near Lake Geneva would became holy ground. I vowed to reach nerdvana.

In my high-school circle, no parents objected to loosing their teens on a convention an hour from home. Modern parents might fear child-snatching psychos; 80s parents might fear devil worship fostered by D&D. Our parents must have realized that fear of Satanists would keep the psychos away. One can’t be too careful.

I couldn’t drive, so I had to find a way to reach the convention. Mike’s dad volunteered to drive, but Mike had made a terrible first impression on my parents, who wanted me to find a better class of friends. Mike was a year younger and struck them as flighty. They forbade me from going alone with Mike.

Joel, a former member of our gaming group, also planned to go. Joel was old enough to drive, but also old enough not to want to spend a day with kids 1 and 2 years younger. If you thought playing D&D was uncool, imagine nearly being a senior and hanging out with children. No way. (Picture a geeky alternative to a John Hughes movie. The time fits well enough and the place matches. Hughes graduated from my high school. Legend says that the sweet Mrs. Hughes staffing the school store in 1981 was his mom.)

So Gen Con hung in the balance. A shaft of golden light pierced the clouds just north of home, possibly illuminating Saint Gary Gygax himself. So I fibbed and told my parents that Joel would drive, even as I agreed to ride with Mike.

Thursday and Friday, the plan worked. Mike and I gamed nonstop. Meanwhile, Joel spent the con shoplifting from the dealers in the exhibition hall. Mike felt as appalled as I did, demonstrating my parents’ poor judge of character in friends for their son.

The convention revealed aspects of the hobby I had never seen. Niche games. Sprawling miniature landscapes. Girls who liked D&D. It all seemed impossibly wonderful.

At Parkside, a wide, glass corridor stretched a quarter mile, linking the five buildings of the campus. Open-gaming tables lined the hall’s longer spans. Every scheduled role-playing session got its own classroom, so no one needed to shout over the clamor. Players circled their chairs around the largest desk. The lack of tables posed no problem, because in those days, everyone played in the theater of the mind.

All the event tickets hung from a big pegboard behind a counter. If you had keen eyes, you could browse the available tickets for a game you fancied.

We played Fez II and had a blast. In “Little-known D&D classics: Fez,” I told how the game transformed how I played D&D.

Titan game advertisement

Learn to play Titan from McAllister & Trampier – an advertisement from the program book

One of the designers of Titan recruited us to learn and play his game. I liked it enough to buy, but I lacked the ten bucks. So the demo led to a purchase thirty years later on ebay. Eventually, I learned that Dave Trampier, my favorite game artist, had co-designed Titan, but I suspect that co-designer Jason McAllister showed us the game.

We entered the AD&D Open tournament and played an adventure written by Frank Mentzer that would become I12 Egg of the Phoenix (1987).

ICE advertisement

Introducing Arms Law and now Spell Law

We ran a combat using Arms Law, the new system that boasted more realism than D&D. I remember how our duelists exhausted each other until the fight reached an impasse. I still took years to learn that realism doesn’t equal fun.

At Gen Con, you could find any game you wished to play, any players you needed to fill a table. D&D was cool. I had reached gaming bliss.

As for my ride the to con, my scheme imploded on Saturday night. Mike’s dad called my dad who repeated my lie: No one needed to drive north to pick up the boys, because Mike and I were riding home with Joel. Oblivious, Mike and I waited outside for his dad.

By midnight, all the gamers had left. A campus official warned us to leave the premises. We assured him that our ride would come soon.

(Young people: Once upon a time, we lacked cell phones. All plans needed to be arranged in advance. Folks grew accustomed to waiting. If Mike’s dad had left home as we thought, no one could have contacted him.)

So we waited in the dark and empty parking lot. Miles of dairy farms and cornfields surrounded us. No one lived near but cows and probably psychos.

After midnight, we tried to find a pay phone, but now all doors were locked. The nearest shabby, murder-hotel was miles away. Worse, we had been told to leave, so now we were trespassers.

By 1am, a maintenance man found us and achieved surprise. Some details may have grown in my memory, but our hands shot into the air as if he were a trigger-happy cop looking to beat up a couple of punks before slamming them in jail.

Instead, he mocked our skittishness and let Mike inside long enough to call. At 2am, Mike’s dad finally pulled into the lot. Forget Saint Gary, I now realize that the true saint was Larry, Mike’s dad.

In 1981, Gen Con reached an attendance of 5000. Dragon magazine speculated, “It’s logical to assume that at some point in its history, the Gen Con Game Convention and Trade Show will not get any larger.” So far, the convention defies logic: In 2015, Gen Con drew 61,423 gamers.

I still have the program to my first Gen Con. You can see it.