Main Page Community portal Recent changes Random page Help

Article Discussion Edit History

Ultimapper and the Gigapolygon Core: Baking Maps from High-Resolution Meshes

Author: Jonathan McDermott, Softimage Developer, Softimage

Thanks to the XSI Gigapolygon core, Ultimapper can generate maps from meshes of 40 million or more polygons. Which means that Ultimapper can handle pretty much anything you can throw at it. This article provides some hard numbers to back up that claim.

Table of contents

1 Workflow 1.1 OBJ Export 1.2 Ultimapper Resolution 2 Performance in XSI 2.1 Import OBJ 2.2 Normal Map – Compute Depths 2.3 Normal Map – Generate Maps 2.4 Ambient Occlusion – Compute Depths 2.5 Ambient Occlusion – Generate Maps 2.6 Depth – Compute Depths 2.7 Depth – Generate Maps 2.8 Normal in Model Space – Compute Depths 2.9 Normal in Model Space – Generate Maps 2.10 Albedo – Compute Depths 2.11 Albedo – Generate Maps 2.12 Material Tags – Compute Depths 2.13 Material Tags – Generate Maps

Workflow

The following are two typical methods of getting data from Zbrush to XSI:

• Use the OBJ Exporter to export high-res mesh (as high-res as possible).
• Use a lower-res mesh and displacement maps.

This document examines the use of a high-res mesh.

OBJ Export

Zbrush can export a mesh to OBJ format, which you can then import into XSI. Investigation shows that XSI can handle as many polygons as ZBrush 2.0 can export.

• Zbrush hits a hard max at 10 million polygons per mesh (it cannot subdivide beyond this; the Preferences > Mem > MaxPolyPerMesh goes only to 10)

• A memory limit of 2 Gb; Zbrush does not support the /3Gb switch nor does it run under 64-bit Windows.

To work around these limits, you can export multiple meshes from Zbrush and then stitch them back together in XSI.

The basics workflow:

1. Create a low-resolution mesh in XSI.
2. Export the mesh to OBJ format.
3. Import the mesh as a Tool in Zbrush and add detail. Subdivide as needed.
4. Export the Tool from Zbrush in OBJ format.
5. Open an XSI scene that already contains the original low-resolution mesh.
6. Import the high-resolution mesh exported from ZBrush.
7. Add an Ultimapper property to the low-resolution mesh and pick the high-resolution mesh as the source.
8. Set the resolution, quality, and maps to be generated, and then click the Generate button.

Ultimapper Resolution

The resolution tested was an estimate at the maximum that would be of use for a game engine. Typically 2048 will be as high as they will want to go. The tests below were done at 2048 and 8192.

Performance in XSI

These are the results of some tests in XSI using an extremely high-resolution mesh. The tests were performed on the following machine:

• 64-bit Windows XP Professional
• 8 Gigs RAM
• 2 Dual-core AMD Opterons, 2.0 Ghz

Import OBJ

# Polygons	# Triangles	Time (seconds)	Memory
1.3 Million	2.3 Million	72s	395 Mb
20 Million	40 Million	588s	2.28 Gb
40 Million	80 Million	1,071s	3.15 Gb

Normal Map – Compute Depths

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	368.2188
2048	High	Lo 10K – Hi 20M	378.9922
2048	High	Lo 3K – Hi 40M	6298.426
2048	High	Lo 10K – Hi 40M	7307.734
8192	High	Lo 10K – Hi 20M	1050.617
8192	High	Lo 10K – Hi 40M	8374.441

Normal Map – Generate Maps

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	116.4688
2048	High	Lo 10K – Hi 20M	120.6094
2048	High	Lo 3K – Hi 40M	268.8594
2048	High	Lo 10K – Hi 40M	293.5156
8192	High	Lo 10K – Hi 20M	917.4023
8192	High	Lo 10K – Hi 40M	1128.879

Ambient Occlusion – Compute Depths

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	104.0156
2048	High	Lo 10K – Hi 20M	109.1563
2048	High	Lo 3K – Hi 40M	253.2813
2048	High	Lo 10K – Hi 40M	291.4922
8192	High	Lo 10K – Hi 20M	781.168
8192	High	Lo 10K – Hi 40M	1025.258

Ambient Occlusion – Generate Maps

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	3291.586
2048	High	Lo 10K – Hi 20M	3234.758
2048	High	Lo 3K – Hi 40M	3967.516
2048	High	Lo 10K – Hi 40M	3471.380
8192	High	Lo 10K – Hi 20M	38104.41
8192	High	Lo 10K – Hi 40M	30466.69

Depth – Compute Depths

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	103.9688
2048	High	Lo 10K – Hi 20M	265.5078
2048	High	Lo 3K – Hi 40M	108.2969
2048	High	Lo 10K – Hi 40M	286.406
8192	High	Lo 10K – Hi 20M	765.7715
8192	High	Lo 10K – Hi 40M	1042.068

Depth – Generate Maps

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	85.40625
2048	High	Lo 10K – Hi 20M	249.6484
2048	High	Lo 3K – Hi 40M	91.46875
2048	High	Lo 10K – Hi 40M	269.6382
8192	High	Lo 10K – Hi 20M	477.8379
8192	High	Lo 10K – Hi 40M	676.6758

Normal in Model Space – Compute Depths

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	103.1406
2048	High	Lo 10K – Hi 20M	108.0781
2048	High	Lo 3K – Hi 40M	265.5078
2048	High	Lo 10K – Hi 40M	286.7949
8192	High	Lo 10K – Hi 20M	755.7539
8192	High	Lo 10K – Hi 40M	1002.82

Normal in Model Space – Generate Maps

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	109.7188
2048	High	Lo 10K – Hi 20M	113.2344
2048	High	Lo 3K – Hi 40M	249.6484
2048	High	Lo 10K – Hi 40M	286.6218
8192	High	Lo 10K – Hi 20M	870.584
8192	High	Lo 10K – Hi 40M	1050.584

Albedo – Compute Depths

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	104.2656
2048	High	Lo 10K – Hi 20M	108.0781
2048	High	Lo 3K – Hi 40M	266.2188
2048	High	Lo 10K – Hi 40M	280.749
8192	High	Lo 10K – Hi 20M	758.334
8192	High	Lo 10K – Hi 40M	970.7422

Albedo – Generate Maps

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	115.5469
2048	High	Lo 10K – Hi 20M	113.2344
2048	High	Lo 3K – Hi 40M	270.9531
2048	High	Lo 10K – Hi 40M	278.395
8192	High	Lo 10K – Hi 20M	919.1152
8192	High	Lo 10K – Hi 40M	1117.148

Material Tags – Compute Depths

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	105.6875
2048	High	Lo 10K – Hi 20M	108.9844
2048	High	Lo 3K – Hi 40M	263.875
2048	High	Lo 10K – Hi 40M	286.6411
8192	High	Lo 10K – Hi 20M	750.6465
8192	High	Lo 10K – Hi 40M	1037.881

Material Tags – Generate Maps

Resolution	Quality	# Polygons	Time (seconds)
2048	High	Lo 3K – Hi 20M	97.89063
2048	High	Lo 10K – Hi 20M	98.8125
2048	High	Lo 3K – Hi 40M	252.2188
2048	High	Lo 10K – Hi 40M	263.2168
8192	High	Lo 10K – Hi 20M	661.8945
8192	High	Lo 10K – Hi 40M	861.0215