Execute run_test_suite.bat on Windows to analyze and convert/clean-up the texture test files in this directory and subdirectories. Running this test file will create various separate output directories where the results are put.

• Standard - standard RGB -> XYZ, where Z is -1 to 1 range
• XYtextures - RG -> XY, and Z is something else (like ambient occlusion, e.g., LabPBR)
• ZZero - RGB -> XYZ, but Z goes from 0 to 1 instead of -1 to 1
• Heightfields - heightfield test images
• NoneOfTheAbove - other test images of various sorts

Each directory's contents:

lava_flow_n.png - a file with almost no bumps, all nearly the same value. File is from the jg-rtx resource pack for Minecraft, license CC-NC-BY-SA.

ntp_heightfield_gimp.png - conversion of the ntp_heightfield.png heightfield to a normals texture with GIMP using these instructions.

ntp_heightfield_gimp_5scale.png - conversion of the ntp_heightfield.png heightfield to a normals texture with GIMP, changing the scale to 5, using these instructions.

ntp_heightfield_normalmap_online.png - conversion of the ntp_heightfield.png heightfield to a normals texture with Normalmap Online, setting "Z-Range -1 to +1".

ntp_resize_128.png - the result file ntp_heightfield_normalmap_online.png resized to 128x128 using IrfanView. Doing a naive resize causes normals to no longer be normalized, see results in directory _output_Heatmap.

ntp_resize_512.png - the result file ntp_heightfield_normalmap_online.png resized to 512x512 using IrfanView. Doing a naive resize causes normals to no longer be normalized, see results in directory _output_Heatmap.

r_normal_map.png - letter R squiggles (see Heightfields directory) in standard form. Not quite correct, making it a good test. From the USD Assets Working Group Normals Texture Bias And Scale test, license CC-NC-BY-SA.

r_normal_map_reversed_y.png - letter R in standard form, DirectX orientation. Not quite correct, making it a good test. From the USD Assets Working Group Normals Texture Bias And Scale test, license CC-NC-BY-SA.

squiggles_gimp.png - squiggles (see Heightfields directory) converted with GIMP using these instructions. GIMP evidently uses the DirectX style for output by default, though has a "Flip Y" and other options to adjust the style.

squiggles_normalmap_online_zneg.png - converted using NormalMap Online, with the "Z Range -1 to +1" box checked.

squiggles_ntp_quick.png - converted by an earlier version of the NormalTextureProcessor.exe's heightfield converter, but without adjusting for roundtripping. Some pixels have one-level differences with squiggles_ntp_roundtrip.png. Use a "diff" program such as Beyond Compare to see the differences between the two. Note if you read this file in and convert it, the result should be the same as squiggles_ntp_roundtrip.png.

squiggles_ntp_roundtrip.png - converted by NormalTextureProcessor.exe's heightfield converter using roundtripping. If you try to clean this file, the output file should be identical, since all the texels are perfectly roundtrippable (see the Algorithms section on the main page).

targa_r_normal_map.tga - (no image shown) same as r_normal_map.png**, the letter R in standard form. Test that Targa input works. Converted from the USD Assets Working Group Normals Texture Bias And Scale test, license CC-NC-BY-SA.

acacia_door_bottom_n.png - the blue channel is ambient occlusion, LabPBR format. File is from the jg-rtx resource pack for Minecraft, license CC-NC-BY-SA.

r_normal_map_reversed_x_0_bias_z.png - letter R in Z-Zero form, and the X axis is reversed (non-standard, just meant as a test). Not quite correct, making it a good test. From the USD Assets Working Group Normals Texture Bias And Scale test, license CC-NC-BY-SA.

squiggles_normalmap_online_zzero.png - converted using NormalMap Online.

grayscale_wood_floor.png - grayscale wood floor sample, non-tiling.

ntp_heightfield.png - text and brushes heightfield, giving a wide variety of slopes

r_bump_map.png - grayscale letter R. From the USD Assets Working Group Normals Texture Bias And Scale test, license CC-NC-BY-SA.

squiggles.png - brushstrokes of similar slopes. Note there are strokes that touch the top edge, causing conversion glitches due to wrap-around; using '-hborder' would be a more sensible conversion, which is done as a separate test.

black.tga - (no image shown) all black, as a test. Non-power-of-two non-square size.

cyan.png - solid cyan, as a test.

fade.png - fade from blue to green to red, as a test.

gray.png - a neutral gray, as a test. Non-power-of-two non-square size.

white.tga - (no image shown) all white, as a test.

wood_floor.png - colored wood floor sample, non-tiling. Currently this file gets misinterpreted as being an XY-only texture, because the Z's are clearly not used properly and the X and Y values, due to the coloration, mostly form vectors that have a length less than 1.0.

yellow.png - solid yellow, as a test.

For images, the license is CC-NC-BY-SA and created by Eric Haines, unless noted otherwise above.