The tab itself
This tutorial will walk you through what each part of the Mesh tab does if you were to start from scratch.
For the purposes of this tutorial, please derive from the Empty Clothing Product, which is product number 2191901.
Click the button...
When you first see an empty Meshes tab, it looks like this. The tab prompts you to add a new mesh and then add an asset to it. To add a new mesh, just click the Add button. When you do, the Add Mesh dialog will appear. Give your new mesh an ID number and click G0 to add your new mesh.
For this tutorial, we will start with mesh ID 1.
When you click Go, you will see a green mesh panel appear. Note that since you typed in the number 1, the mesh is entitled 1. This means that the mesh is now built for Body Part 1 - which is the avatar hair. To learn more about Body Parts, please consult the Avatar Body Parts tutorial. Although body parts are for avatars, the overall process you just went through works for every 3D product type including Rooms, Furniture, and accessories.
If you ever mistakenly add the wrong ID for a mesh, just click the Remove Mesh button and start over.
One Avatar Body Part behaves a little differently than the rest. If you had typed a 0 when you added your mesh, the Mesh Scale panel would be enabled when the Mesh is created (see image below). This is because Mesh Scale only works for avatar heads...and the avatar head is Body Part 0. If you would like to learn more, please consult the Mesh Scale tutorial.
A mesh asset in IMVU is an asset that has been exported from a 3D software package that supports Cal3D exporters. IMVU has written Exporters for 3DS MAX versions 2007-2017, but there are other exporters available on the internet for other software packages.
Cal3D exports a mesh file called .XMF. Only .XMF assets are supported in the Mesh Asset panel. For this section of the tutorial, we added a hair .XMF file that we had previously exported.
When we added that file, a few things happened. The most noticeable is that the Materials panel appeared. However, two other things also happened. The first was that the name of the mesh .XMF asset was applied to the title of the Mesh and the button for the mesh in the navigation. Although some mesh names are meaningless, these names can help you find the mesh you're looking for when you have many of them.
The second thing that happened was that the number of sub-meshes is listed. This is helpful for seeing whether your mesh .XMF asset has the correct number of sub-meshes.
When you add a mesh .XMF asset, materials for that asset are automatically created. The number of materials is defined by the .XMF asset itself. A material is a combination of asset and parameters. Another thing defined by the .XMF mesh asset is the material ID number. This number does not have to be sequential. ie - a mesh does not have to define material ID 1, 2, 3. Rather, as is the case in the above image, a mesh can refer to materials 4 and 10. You can see the ID number in the upper right corner of the material preview.
If the product you're deriving from already defines assets for materials in your new .XMF asset, the Editor simply shows those for reference. If you make no changes, your product will display the parent product's texture assets.
To switch between materials, just click on their preview in the right hand nav. When there are lots of materials, you can use the scroll bar or up/down arrow keys to browse through and select them.
Supported file types - The assets that a material can accept are .jpg, .png, .gif, .bmp and .tga image file types.
Submesh info - The top panel in any material is the submesh info panel. The information in this panel describes how many polygons and vertices in the mesh are associated with this particular material ID. If you don't use this information, you can minimize this panel.
A new product contains all its parent product's assets, such as meshes, textures, body part IDs, etc. Create Mode will show you all of these assets—the "inherited truth" of a product.
When creating your new product, you may not need to change each of these areas—you may only want to change a texture of a product, or the mesh and texture but leave the body part ID. Whichever assets you do not change will show up in your new product , and will be visible in the Editor.
For example: if your new product has a mesh that only defines two material IDs but the parent product's mesh has defined three material IDs, that third material ID will always be shown in the Mesh tab, but not on your actual product. Making any change to this extra, unused texture will have no effect on your product. You also cannot delete this 'extra' texture. You can tell that there is an unused material ID in a product if the Triangles and Vertices say "undefined".
The Texture Assets panel contains two slots for image assets. The texture slot is for the color texture associated with the material. If the material added was referenced by the product you're deriving from, then the asset previews that appear here will be from the parent product.
If the parent product does not define the material ID you have added, you will see an empty material slot.
Texture Do's and Don't's
We strongly recommend you consult the Texture tutorials to learn how to best prepare your textures for use in IMVU.
IMPORTANT: Your textures need to be 256x512 pixels or smaller or they will be reduced in image size automatically. This can have a negative impact on the way your product looks so make sure you're in control: keep your textures small and use them wisely.
Texture Assets - Opacity
You can add and delete Opacity Maps. An Opacity Map is a grayscale image that determines what areas of your texture are opaque, transparent, or translucent. To load an Opacity Map you will need to click on the Edit button in the Opacity Map slot. Opacity Maps are loaded separately from the Texture Map, and can be added to or removed from any Material. You can remove an Opacity Map by clicking on the Delete button.
NOTE: if you add or subtract opacity, you are writing a new XRF asset under the hood. This means that your product no longer retains the Asset derivation link to the parent product. It will still be derived from the parent insofar as pricing and other assets are concerned. However, if the parent product were to make a change to its texture assets or settings, your new product would not inherit those changes.
The Materials Parameters panel is where you can toggle on or off various settings for each individual material. Any parameter change made in this panel affects only its material. If you want all Materials to share the same parameter settings, then you need to manually set them for each Material.
Two Sided: Normally, a texture is displayed only on one side of a piece of geometry. This is because the user rarely sees the inside of geometry. For example, there is no need to render a texture on both the outside and inside of a ball because only the outside of the ball is visible. However, when you have a glass window or some draping hair, you might want to the texture to render on both sides of the geometry. This first check box tells the Material to render on both sides.
Self Illuminated: Checking this box makes the material unaffected by the Scene's lighting. This is handy for things like fire or anything that you want to stay bright. Fog Override: Checking this box makes the material unaffected by fog. This is very handy for sky textures. Vertex Colors: If you have exported a mesh that contains vertex colors, you can view them on a per-material basis by checking this box in each material. If you'd like to learn more about Vertex Colors, please consult the Vertex Colors tutorial.
NOTE: If your textures are appearing completely black, this means that the Vertex Color check box is selected, but there is actually no Vertex Paint on that part of the Mesh. To remove the black, un-check the Vertex Color box.
Use Blending: When you add an Opacity Map, you can choose whether the Material uses smooth blending or harsh blending. Leaving this check box unchecked leaves the blending ragged and harsh. Checking this box leaves the blending smooth.
Blending Mode: If you checked the Use Blending checkbox, the Mode drop down tells the Opacity Map whether it can be an Additive blend or a Composite blend. Additive blending literally takes the texture and "adds" light values to it based on values in your opacity map. The more additive textures you have in front of one another, the brighter and brighter they get. This is handy for things like shafts of light.
Composite blending shows you a smooth blend of your Opacity Map and Texture assets. Unlike Additive blending, Composite has no additional effects applied to it.
Just below the Material Parameters are the Texture Animation controls. A texture can Scroll over a surface at various speeds and directions (like the lava texture above), or Cycle through frames of animation that exist on a single texture (as seen in the flame texture below).
Cycling allows you to sample frames within a given texture.
Cell width and Cell height are used for Cycling animations. The number here is in pixels and tells the Material what size you want your animation cell size to be. For example, if I had a texture that was 128x64 and I happened to have four separate frames drawn across it from left to right, my Cell width would be (128/4=) 32 and my Cell height would be 64.
Offset X and Y are used for Cycling animations. They allow you to offset where your first frame of a Cycling animation begins. This is very handy if you have one large texture that contains several Cycling animations on it. Set your X and Y to 0, 0 to use the full texture, or different values to use a subset of the texture. The cell rectangle does not have to divide the dimensions of the texture evenly, and it doesn't have to have the same proportions as the texture.
Start Cell is used for Cycling animations and tells the animator which frame to start on. This is handy for things like flickering candles where you may want to use the same texture on a bunch of candles but don't want them to animate the exact same way (meaning looking EXACTLY the same in IMVU). With this feature, you could use the same texture on multiple candles but have them all appear different in IMVU. Of course, you COULD just make new textures per each flickering candle but that would needlessly increase the file size of your product.
Direction X and Y are used for Scrolling animations. These deltas specify the amount (direction and speed) to scroll, positive numbers going down and right. The delta is in Fixels (fractional pixels). Try typing in numbers like 1, 2 or 3 and then try -1, -2, -3 to see what happens.
Num Cells allows you to define how many Cells the animator should include in a given Cycling animation. By setting Offset X/Y or Start Cell, and then setting the number of cells with this function, you can use a single texture sheet for multiple sets of cells.
Frames/Cell allows you to slow down the animation. You can specify that it takes multiples of 1/30 sec to advance a frame of animation.
For an example of both texture Scrolling and Cycling, please consult the Super Furniture Product Tutorial