Large Area Nationals (The KrackerJack1 Technique)

When I saw KrackerJack1's KJ Acres I couldn't believe it. It really bugged me as to how he did it. I spent my whole lunch trying to figure it out and I came up empty. It then hit me in the afternoon what he must have did. I asked somebody on Twisted D.I.R.T. to check out, if it was as simple as changing the first line in the .TER (GridResolutionInFeet). TNT_Guru250 tried it and let me know that it was. That night when I got home I figured I had the answer of a way to easily automate the widening of an SX converted track. One of the first things that you do when you convert is to widen the track where ever you can. I had wanted to come up with a simple way of scaling the track up by 20-25 percent. I tried setting the GridResolution to 3.75 and it worked. Except for the spline. Fortunately the type of track and the placement of the starting line made it relatively obvious to me what was happening. If I had used a different track it would have been much harder to figure out. I whipped up a perl script to adjust the spline and it worked.

The next day I e-mailed KrackerJack1 and asked him a few questions and offered him my script for doing the spline. He explained to me how he did the spline for KJ Acres. He also confirmed my suspicion that he had used a 15.0 for GridResolution. He answered my questions and asked me to make available some information on my site. Here are his comments about KJ Acres.

KrackerJack1's Comments:

On making the spline

A buddy I grew up with showed me how to use MS Works. I just used MS Works to open the .TXT that the spline editor puts out. I opened it in a spreadsheet and let it do all the math then saved it, Done.

On making the track

Well I'm not sure how long it took me to make the track. It was a while but I found that there are a few techniques for making the jumps and burms smooth, but its very tough to make a steep jump that dosn't look sharp. And yes I used a grid resolution of 15 which is 5 times bigger. I first thought that would make the track 5 times bigger in area, but it is actually 25 times bigger in area, but 5 times bigger in x y and z cordinates. As far as the disp map I think you can go as high as you want. I used 504x504 but created it in 1016x1016 then sized down. I was using 1016 for asc but tried 504 and it was better and much faster. It really doesn't matter it can be 700x700 or whatever. You dont have to stick with the Rainbow numbers with disp map but you do with textures.

Actually you can change texture size too but that will kill the awesome fps and dramatically increase file sizes. I stayed with their sizes and thats why texture are not the best looking, However I feel they are more than acceptable.

KJAcres is 338 acres and the mountain is 525 feet high, which is about the max you can go without the rider smearing in the sky if you know what i mean.

My Comments

What I find impressive about KJ Acres is not only did KrackerJack1 pull off stretching the grid out to 25 times the normal size, he also did the same with the textures. What he had to work with, is equivalent to making a National texture at 203x203 pixels. If you've ever made a National texture you will know that 1016x1016 is not enough and you have to accept compromises. To throw away all those pixels and still have a good texture is amazing. To put it in perspective a single track piece in the SX environment is 126x126 pixels. So imagine stretching out something just a little bigger then an SX track piece to fill the area of a National and you'll understand what he accomplished. .

The Magic Value

[ElevationData]
GridResolutionInFeet=15.0 Right in front of your nose
TerrainType=NATIONAL
TotalElevationFiles=73
TotalTextureMapFiles=2
TotalTexturePlacements=1
TotalTargetWidth=1280
TotalTargetBreadth=1280
ElevationFormat=ASC
ElevationDefault=0
ElevationAtEdge=15.0
TextureFormat=8
ShareTextures=1
ShareGeometries=5
UpPropagateTextures=1

Perl Scripts

Here are some Perl scripts that I have written to help me with MCM stuff, including make splines for the larger nationals. To use these scripts you have to have a perl interpreter installed. I recommend ActiveStates Active Perl.

Get the perl scripts here

Here is a brief description of the scripts/batch files contained in this zip.

Perl scripts:

AddZ      - Add a value to all the Z's in an ASC.
AdjSpline - Called by the MakeSpline batch file to scale/adjust the spline for larger grid resolutions.
ScaleZ    - Multiply a value to all the Z's in an ASC file.
ASCStats  - Prints out statistics on the values in an ASC file.

Batch file:

MakeSpline - Calls AdjSpline.pl to scale/adjust the spline for larger grid resolutions.


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Command line options:

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	AddZ ASCFile.asc zvalue >Output.ASC

		Where ASCFile.asc is the input ASC and zvalue is the value to add
		to all the Z's contain in the ASC file and Output.ASC is the new
		ASC file containing the updated Z values.

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	ASCStats ASCFile.asc

		Displays Min/Max Coordinates

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	MakeSpline GridResolution SplineName [-quarry|-nat [NumberOfGrids]]

		where GridResolution matches the value in the .TER file
		and SplineName is the name of your .TXT file without the extension.

		Optionally you can pass -quarry to adjust the spline to the
		different coordinates of a quarry. -nat is the default.

		To make a spline that covers larger then the center grid you can
		pass the number of grids. For the entire National area it is 5 and
		for the entire quarry area it is 7. To use this option you need to
		create a picture of the entire area scaled to 1016x1016 and make the
		spline using MCMSplineEdit.

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	ScaleZ ASCFile.asc zvalue >Output.ASC

		Where ASCFile.asc is the input ASC and zvalue is the value to
		multiply with the Z value's contained in the ASC file and
		Output.ASC is the new ASC file containing the updated Z values.

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INSTALLATION

Just unzip into the directory that you use to work on your ASC files and splines.

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