The size of the DXF is NOT a factor. I frequently work with DXFs that are 50mb and up with no problems. I use terragen 0.7.28. It has an export button on the terrain window. Export to "Raw 8 Bits". Using PSP (or similar image editor), you will need to import the .RAW file you saved from terragen. It will be 257x257, greyscale and bottom up (flipped). PSP opens the files just fine. Save it back out as a BMP. Open Bryce, create a terrain, go into the Terrain Editor and load the BMP you saved out from PSP. Voila! Terragen terrain in Bryce, no screwing around, no huge DXFs.