Problem with baking sculpt meshes with Jass2

[Suki Hirano]

I installed Jass2 plugin for Blender, and opened an existing blender project. I selected my objects then went to render -> bake sculpt mesh ->  bake, but nothing happens, no errors or anything. The UV/image editor window remains an empty grid. Does anyone know how this plugin works? Thanks.

[Drongle McMahon]

My guess, coming from Primstar, is that you have to start with the special sculpt meshes (Add->Sculpted mesh script), to get a mesh with the correct UV map. You can't use an existing mesh. Then you must only push vertices around, no adding or deleting and no extrusion. The UV map must stay as it is. This should all be described in the machinimatrix tutorials. Look at the recent one that explains how sculpties work. It helps a lot if you understand that clearly. Sorry if you already watched those.

[Michael Kyuzo]

 

---

Drongle McMahon wrote:

My guess, coming from Primstar, is that you have to start with the special sculpt meshes (Add->Sculpted mesh script), to get a mesh with the correct UV map. You can't use an existing mesh. Then you must only push vertices around, no adding or deleting and no extrusion. The UV map must stay as it is. This should all be described in the machinimatrix tutorials. Look at the recent one that explains how sculpties work. It helps a lot if you understand that clearly. Sorry if you already watched those.

---

Let me preface this response by saying that I have not used Jass2 or Primstar2.  I have used Primstar1 on sculpts I've made in both blender 2.49 and 2.58.  You don't have to use the built it sculpt mesh types.  You can model your mesh from scratch, using extrudes, mirror modifiers, etc, but you have to keep in mind the max number of faces, and the layout of your mesh.  If you do model from the ground up, you'll need to manually mark your own seams, and use the 'follow active quads' unwrap method.  Then you must resize your uv layout to fully fit the uv space without overlapping verts. 

 

The real key to getting the sculpt map to bake when using this workflow is to ensure that your uv layout is named properly.  By default blender will call the first uv layout 'UVTex'.  The Primstar scripts look for a layout called 'sculptie' to use for baking.  You can rename the uv layout in blender.  For blender 2.49 go to the 'Editing' buttons and in the 'Mesh' panel you'll find 'UV Texture'.  In blender 2.58 you can find the 'UV Texture' panel in the 'Object Data' buttons.  I would start by checking to see what your uv layout is named.  Also, be sure that you have an image assigned for baking.  Hope this helps.

 

NOTE: In the above image you should change the highlighted UVTex to read sculptie instead

[Drongle McMahon]

Ah. That's good to know. Having only used the preformed meshes, however, that does sound a lot easier and safer to me.

[Michael Kyuzo]

The preformed meshes are by far the quickest and easiest way to get going.  It also ensures that you have the uv layout set up correctly and that you have the correct number of verts.  I have found though, that at times, it can be a lot quicker to model from scratch and just do the unwrap myself afterwards.  For instance, when I'm making a sculpt with several linked parts, such as a wooden pier, or if I want to have symmetry that could be tedious to achieve by hand, I'll just model from scratch, using the modifiers and such.  You just have to plan ahead and know what LODs you're targeting and what sculpt map layout (square, oblong) you're going to be using ahead of time.

[Vladi Hazelnut]

you need a uv mesh in that second window to begin with for it to bake to. Try going to object mode and use the "sculptify" script to see if that will make a uv mesh for you. Then you should be able to bake to it and save it.