FX Vertex Animation Baker

Intro:
The vertex animation Baker is a tool created to export animated vertex positions into a texture map which can then be read by the Editor. This comes from a GDC Talk from Naughty Dog's Andrew Maximov. The idea is that simple vertex animations can be done in the Vertex shader on the GPU much faster than those done through bones and skinning. This gives us the ability to animate things like background characters, creatures, insects, and large schools of salmon at a relatively low cost-- These can even be done as mesh particles, and controlled by particle emitters.

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Create Main Mesh UV's:

Whatever model you export from Maya (the Main Mesh) will have to have a special UV set that can be read by the arch editor. Arch will currently only accept uv_0 through 8. (Note: The Arch engine currently won't accept gaps between uv set numbers, like using uv_0 and uv_2 while skipping uv_1.)

The "Create Main Mesh UV's" button will copy the UV's from the mesh's Map1 UV's to a new UV set selected from uv_0 through uv_7 (the current default is uv_2). It arranges the U values of the vertices by index, one vert per pixel, from 0 to 1 on the texture map. All the V values are set to 0.

Position Map Example (Sockeye Salmon, scaled down from 1214 width to fit screen):

Animation Mesh (this is optional): You can use your main mesh as a bindpose, and create animation data that offsets the vertex positions/normals from the main mesh's origianal position and normals. Use the plus button to add the selected mesh, use the minus to clear.

Pad Texture Sizes to Power of 2: This will add extra pixels to your texture maps to increase their texture size to a power of two, in case it is required by arch. This is factored into generating UV coordinates as well.

Create UV Settings:

UV dropdown: choose between 0 through 7. Make sure there are no empty uv_ sets between UV_0 and the one you are using or the editor won't like it.

Create Main Mesh UV's: Button to generate the new UV set on the main mesh.

Save File Type:
Save as .tga: Save animation data in targa format.

Save as .exr: Save animation data as normalized floating point exr file, 16-bit.

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Bake Animations :
Bake Position Animation: if checked will create a position map.

Bake Position Animation as an Offset: if checked and you are not using an animation mesh, the position map's values will be offset distances from the position values on the first frame (this is more accurate when checked, as the values are smaller). Otherwise, the positions will be from 0,0,0.

Bake Normal Animation: if checked, will create a normal map.

Bake Normal Animation as an Offset: If checked and you are not using an animation mesh, the normal map's values will be offset vector values from the normal values on the first frame (this is more accurate when checked, as the values are smaller). Otherwise, the normals will be from 0,0,0.

Bake and Average All Vertex Normals (Slug-Mode): It was found that the command for getting Normals using Maya's API was returning ( 0, 1, 0 ) for any vertex's average of normals, instead of the actual average, especially if the normals have been combed. This checkbox uses the pymel command and manually averages the normals. on a vertex- much slower, but more accurate.

Bake Vertex Color Animation: if checked, will create a map of vertex colors over time. Can be used to drive shaders and blend between texture maps/normal maps in the engine.

Use Closest Power of 2 Color Range: If this is checked, the total range of position values (as distance from zero in centimeters) is rounded up to a power of two exponent. The exponent is stored in the Blue value of the pixel in the upper right hand corner. Blue 0 = 1 cm, Blue 1 = 2 cm, Blue 2 = 4 cm, Blue 3 = 6, ... Blue 6 = 64, Blue 7= 128, Blue 8 = 256 cm... etc. Otherwise the colors are scaled to the maximum distance from zero and the upper right hand pixel will be Bright Red.