Downloads and Support

The Prim Composer 1.02 release focuses on sculpted prims and adds new aspect ratios for sculpties as well as the ability to move the pivot point of a sculptmap. SculptGenMax default settings have also been merged with the Prim Composer preferences dialog.

New Sculpt Aspect Ratios

In the original implementation of sculpted prims, sculptmaps encoded a fixed number of mesh faces (32 x 32) in a 64×64 pixel texture. Larger bitmaps could be used (e.g., 128×128, 256×256, etc.) but they were still limited to 32×32 faces and served no useful purpose after lossless uploading was implemented.

A change is coming! The newest Release Candidate viewer (1.21) adds support for sculptmaps with a variable aspect ratio. As a result, we are no longer limited to 32×32 faces. 16×64, 8×128, and 4×256 faces are now possible by using a non-square texture of 32×128, 16×256, and 8×512 pixels, respectively. These new sculptmap sizes allow a mesh to have a different aspect ratio while maintaining 1024 as the maximum number of faces in the sculpt. By using sculptmaps with different aspect ratios, it is now much easier to model objects that have more detail in a particular dimension, for example, a rope.

In addition, it is possible to create sculpties with less than 1024 faces, since intermediate aspect ratios are also allowed. Thus, a 32×64 pixel texture might generate a sculptie with 16×32 = 512 faces. I say “might” because it’s actually more complicated this. The details of intermediate aspect ratios are currently being refined in JIRA VWR-9384. Please vote for it!

When this is finalized, we will be able to tailor the number of faces to the complexity and shape of the sculptie we want to create. If we don’t need 1024 faces, we can use fewer. This is especially important with regard to lag because fewer faces means a smaller texture to download and, more importantly, fewer triangles to render in the viewer.

Prim Composer 1.02 supports all of the sculptmaps with 1024 faces (texture sizes: 4×1024, 8×512, 16×256, 32×128, 64×64, 128×32, 256×16, 512×8, and 1024×4). As soon as VWR-9384 is finalized, I will add support for the intermediate sizes. Vote for it, please!

New Options

In 1.02, SculptGenMax has a new “Aspect Ratio” section to assist in creating sculpted prims from 3ds Max objects. Prim Composer also automatically detects the aspect ratio of any sculptmaps that are imported using the Sculpt creation rollout and automatically generates the appropriate aspect ratio in sculpts that it exports. Sample sculptmaps using the new aspect ratios are available in the “sculptmaps/aspect” folder of the zip file.

Move the Pivot of a Sculpted Prim

The other big feature in Prim Composer 1.02 is the ability to change the pivot point of a sculptmap. Normally, when a sculptmap is created, its pivot point is placed at its center. However, there are occasions when it is desirable to move the pivot point. A good example is a door sculptie. Putting the pivot on the edge can make it easier to script the open/close door rotations in LSL.

1.02 adds a new section to the SculptGenMax dialog in Prim Composer called “Pivot Offset”. By default, the pivot offset is 0 for all dimensions. This puts the pivot in the center of the sculpted prim. A pivot offset of -0.5 or +0.5 will place the pivot on the edge of the sculpt. To use this, you must change the pivot offset and then generate a sculptmap in SculptGenMax. If you want to preview the location of the pivot point, you can paste the sculptmap back into the scene. Finally, you should save the sculptmap to disk and upload it manually to Second Life or OpenSim.

This new feature has several limitations. First, a sculptie created in this way will not be exported properly by Prim Composer. You will have to manually upload the sculptmap to SL/OpenSim instead of using the normal upload process via maxport. This is a limitation that will be removed in a future version of Prim Composer.

A more fundamental problem has to do with the way sculpties work. Shifting the pivot point reduces both the precision of the sculptie and its maximum size in SL. With a pivot offset of [0.5, 0.5, 0.5], the precision will be reduced by half in each dimension and the sculpted prim’s maximum size will be reduced to 5m x 5m x 5m.

I should note, however, that size reduction is not always a bad thing. In fact, this is the same principle that allows us to create tiny sculpties, since the prim’s minimum size is also reduced (to 0.005m x 0.005m x 0.005m). The important thing is to know that it will happen.

Generally speaking, you should not move the pivot unless you have a good reason. Also, I can’t guarantee that moving the pivot will work well with the “proportional” option.

What’s to come!

Well, that’s it for this week. I’ll be releasing 1.02 late tonight EDT. The next release will be in about a month unless we have major bugs that pop up between now and then.

I still have some work to do with sculpted prims. After VWR-9384 gets implemented in the RC viewer, I’ll add support for intermediate aspect ratios. I also want to add support for precision sculpties and LOD management similar to what Domino Marama has done for Blender. See these excellent tutorials on Machinimatrix for a demonstration of the concept: Precise sculpted prims: “Level Of Detail” and Precise Sculpted Prims: “The Arch Example”.

But my immediate goal is to enable exporting from SL/OpenSim to 3ds Max. Please no threads about copyrights or content theft. I’ll put in appropriate protections.

Stay tuned…