Sketchfab How to Upload Model With Xgen

April 14, 2022 Post a Comment

Bence Bodó'south Ammit is an splendid example of hair rendering on Sketchfab. I invited him to share his technique in this new Sketchfab tutorial.

There are a number of techniques for creating real-time fur, short and long hair. This tutorial is about the creation and material settings of the polygonal method that relies on having partially transparent planes (a.yard.a. hair cards) with overlapping transparency textures for achieving a furry look.

Annotation that your results depend on your vertex count (the number of hair cards), texture budget (texture resolution, thickness of hairs)!

The process:

Base geometry, texture map cosmos, blocking in the hair with a particle system.
Pilus texture creation.
Hair Card placement.
Fabric setup.
- Classic rendering
- Physically based rendering

Hair texture creation

Y'all tin can hand pigment your pilus textures (east.thousand. using photoshop) or do what I did for the Ammit animate being, which was to render them out in a 3D parcel (e.g. Zbrush).

Get a simple airplane, have some particle hair on information technology, just a few strands, brand the aeroplane itself invisible and render a color map, a transparency map (greyscale epitome with black parts where there would not be hairs) and a normal map from a camera looking at your scene. The color map does non need to have an alpha channel. We will bulldoze the transparency with a separate greyscale texture, the alpha map. Brand a few of these and combine them into i texture sheet.

Tips:

Place the roots of the hairs in the bottom area of the texture to help accomplish a layered look.
Don't place the roots at the very bottom in a line.
Don't make the textures besides dumbo.
Cheque that the hairs show up nicely on the texture, that you lot have enough pixels for their thicknesses.
For the color map don't use black or white backgrounds, but choose a color that is ascendant in your hairs/furs.

Haircard placement

Open up your base mesh (the Ammit model in my case) in your 3D software of choice. Create a sample hair card for every fur type that you take. UW map them to only have the approximate texture parts. Scale the haircards to the same size approximately equally the sculpted hairs on your base of operations geo. Set up up a viewport material with condiment transparency. Without this the cards will await bad, block each-other, and brand the placement process a lot harder. In Maya this is washed by connecting a colored texture with transparency and therefore with an blastoff channel to the incandescence channel of a Blinn material. Y'all can create this texture as a combination of the previously used ones in any epitome editor. Next, distribute copies, or instances of the hair cards on your base, either manually, or using a particle system, geometry painting or instancing. I did information technology past manus, snapping each pilus card copy to the base mesh. The Ammit fur with 959 faces took only two-3 hours and this way I had total control over placement. Finally consign the hair cards equally ane object with a lot of individual faces.

Tips:

Have a normal map with sculpted fur on the base mesh.
Have a simple geometry for the pilus, 4 vertex planes for short pilus should do information technology, the more cards you have, the better it will expect.
Place the origin/pivot bespeak of each pilus card on the middle of the lesser edge and then you can easily snap and rotate the cards.
Its not a problem if the cards intersect and/or get into the base geometry a fiddling.
Place the hair cards with less dumbo fur on edges of the hairy area.
Piece of work asymmetrically in the middle areas.
Scale and rotate the hair cards on unlike axes for diversity's sake.
Call up about rigging! With manual hair placement comes transmission skinning. In some cases it is meliorate to have a particle system with instanced hair cards attached to a rigged base mesh in order to use the skinning data of the base of operations mesh for the hairs. E.one thousand. in Blender you simply place the particle modifier nether the armature modifier and the fur will follow the base mesh'due south skinning.

Fabric setup. – Classic Renderer

Import your base mesh and pilus mesh into Sketchfab.
Connect the color texture to the diffuse aqueduct as an RGB image with trilinear filtering.

Connect the normal map to the normal channel as an RGB image with trilinear filtering.

Connect the transparency map to the transparency channel every bit a luminance prototype with trilinear filtering. Ready information technology to blastoff blending otherwise information technology won't look good. Gear up the transparency to a depression value, similar 10 to have some blending.

In order to recoup for the loss of hair visibility we will innovate some emission every bit well. You can utilise a split texture for it as well, but I observe that a solid color does fine.

For kick you tin can play with the spectacularity every bit well, I connected the transparency texture to the glossiness channel to mask out the invisible parts and used a simple solid colour again. But the emission cancels out the bulk of the specular effect.

And the final fur in live activeness:

Ammit_classic
by Bence Levente, Bodó
on Sketchfab

Material setup. – PBR

For physically based rendering I chose to follow the specularity workflow, just it does not make a real difference here. The main difference to classic rendering is that the emission tin be a lot weaker.

Connect the color texture to the albedo channel as an RGB image with trilinear filtering.

Connect the normal map to the normal channel as an RGB epitome with trilinear filtering.

Connect the transparency map to the transparency channel equally a luminance prototype with trilinear filtering. Set it to alpha blending otherwise it won't look proficient. Set the transparency to a depression value, like 10 to have some blending.

In social club to compensate for the loss of hair visibility we will innovate some emission as well. Once over again you can use a separate texture for it as well, but a solid color does simply fine. Every bit I said in the beginning here a lower emission value is enough, for me information technology was something like twenty.