Baking Hair & Fur for Games MiniTutorial
mod
My tutorial writing skills are no where near where they should be. Re-reading it I think I can make it much clearer. I'll take another stab at it.
1) Plot your hair guides using splines. Align your splines so they will form poly strips. For the purpose of this example it will look as simple as 3.
2) Select the first spline on the left and under the Geometry roll out turn on <font color="orange">Attach</font> and click the next spline in the poly strip. You are making the vertical edges for the poly strip.
- Keep attaching splines until all the splines that make up that strip are connected. You should have something that looks like 2. One spline with a few floating edge segments.
- Name this object <font color="red">HairLOW</font>
- <font color="orange">Clone the object</font> and name it <font color="green">HairHIGH</font>, we'll be coming back to this in a min.
3) Select <font color="red">HairLOW</font> and under the </font>[/b][/i]Geometry roll out</font>[/b][/i] turn on <font color="orange">Cross Section</font> (should be under the attach button you used earlier).
- Following the same pattern as above selecting each segment. The cross section tool should draw dotted lines from one segment to the next when you are finished it should have built all the edges to your poly strip and should look like 3.
- Add a <font color="orange">Surface modifier</font>, then the <font color="orange">Edit Poly</font>. You can collapse the history stack on this object if you wish.
4) Select the <font color="green">HairHIGH</font> spline. Apply the modifier <font color="orange">Hair and Fur (WSM)</font> it should be close to the top of the list.
- Under the <font color="orange">tools roll out > Presets > load</font> a preset hair type, it might take a min to load. You can take this time to tweak the hair or leave it as is.
5) Switch to <font color="orange">perspective viewport</font> (hair and fur will not render from the ortho views front, left, right, ect)
- Select the <font color="red">HairLOW</font> object and adjust the object so it fits around <font color="green">HairHIGH</font>.
- At this point it might be a good idea to set your render output size to something square like 512x512 and turn on Safe Frame Mode so you can see the bounds of the render area.
- Render out a <font color="orange">32bit TGA with Pre-Multiplied</font> checked, this will give you a nice alpha mask to use as an opacity map.
Note: If you think you might have to render this clump again, you can create a camera as a viewport place holder. Click <font color="orange">Views > Create Camera From View</font>. You can switch your viewport back to perspective so you don't accidentally move the camera. Switch the viewport back to this camera if you need to re-render this clump of hair.
- Apply the <font color="orange">Unwrap UVW</font> modifier pick <font color="orange">Planar</font> and select <font color="orange">align to view</font> and then click <font color="orange">fit</font>. The Yellow Unwrap projection should almost match the bounds of the Safe Frame. If not you can adjust it using the scale tool or the UV Editor.
- Hide <font color="green">HairHIGH</font>
6) Create a <font color="orange">new material</font> placing the TGA you just rendered in the <font color="orange">defuse and opacity map slots</font>. Apply it to <font color="red"><font color="orange">HairLOW</font></font> Under the <font color="orange">opacity map > Bitmap Parameters rollout > Mono Channel Output: set it to Alpha</font>.
7) Do that a few more times to get a few different clumps or copy a more complex hair style. Once you get the work flow down, you can block out clumps of hair and fairly accurately copy a high poly hair style.
1) Plot your hair guides using splines. Align your splines so they will form poly strips. For the purpose of this example it will look as simple as 3.
2) Select the first spline on the left and under the Geometry roll out turn on <font color="orange">Attach</font> and click the next spline in the poly strip. You are making the vertical edges for the poly strip.
- Keep attaching splines until all the splines that make up that strip are connected. You should have something that looks like 2. One spline with a few floating edge segments.
- Name this object <font color="red">HairLOW</font>
- <font color="orange">Clone the object</font> and name it <font color="green">HairHIGH</font>, we'll be coming back to this in a min.
3) Select <font color="red">HairLOW</font> and under the </font>[/b][/i]Geometry roll out</font>[/b][/i] turn on <font color="orange">Cross Section</font> (should be under the attach button you used earlier).
- Following the same pattern as above selecting each segment. The cross section tool should draw dotted lines from one segment to the next when you are finished it should have built all the edges to your poly strip and should look like 3.
- Add a <font color="orange">Surface modifier</font>, then the <font color="orange">Edit Poly</font>. You can collapse the history stack on this object if you wish.
4) Select the <font color="green">HairHIGH</font> spline. Apply the modifier <font color="orange">Hair and Fur (WSM)</font> it should be close to the top of the list.
- Under the <font color="orange">tools roll out > Presets > load</font> a preset hair type, it might take a min to load. You can take this time to tweak the hair or leave it as is.
5) Switch to <font color="orange">perspective viewport</font> (hair and fur will not render from the ortho views front, left, right, ect)
- Select the <font color="red">HairLOW</font> object and adjust the object so it fits around <font color="green">HairHIGH</font>.
- At this point it might be a good idea to set your render output size to something square like 512x512 and turn on Safe Frame Mode so you can see the bounds of the render area.
- Render out a <font color="orange">32bit TGA with Pre-Multiplied</font> checked, this will give you a nice alpha mask to use as an opacity map.
Note: If you think you might have to render this clump again, you can create a camera as a viewport place holder. Click <font color="orange">Views > Create Camera From View</font>. You can switch your viewport back to perspective so you don't accidentally move the camera. Switch the viewport back to this camera if you need to re-render this clump of hair.
- Apply the <font color="orange">Unwrap UVW</font> modifier pick <font color="orange">Planar</font> and select <font color="orange">align to view</font> and then click <font color="orange">fit</font>. The Yellow Unwrap projection should almost match the bounds of the Safe Frame. If not you can adjust it using the scale tool or the UV Editor.
- Hide <font color="green">HairHIGH</font>
6) Create a <font color="orange">new material</font> placing the TGA you just rendered in the <font color="orange">defuse and opacity map slots</font>. Apply it to <font color="red"><font color="orange">HairLOW</font></font> Under the <font color="orange">opacity map > Bitmap Parameters rollout > Mono Channel Output: set it to Alpha</font>.
7) Do that a few more times to get a few different clumps or copy a more complex hair style. Once you get the work flow down, you can block out clumps of hair and fairly accurately copy a high poly hair style.
Replies
Also, some end-result images wouldn't hurt
also vig, check out my new thread in pimping and previews, think you might like what im doing
Great tutorial!
For things like animals I do the hair-styling on the uv's transferred to the mesh via channelinfo and render it from the top.
Miguelito, I don't understand the 5cm restriction could you explain? I've used it to make long haired characters and it works really well. Of course you still run into the pain of animating long hair... It will make hair as long and as complex as the spline. I showed the most basic approach (short poly strip) because I didn't want it to be overly complicated.
If you mean the hair frizzes out toward the end making it hard to capture in the render, then you can adjust the "Frizz Parameters". You also might want to select all the verts in the HairHIGH and from the right click quad menu, set them to smooth instead of corner.
Also this method isn't meant to capture hair applied to a scalp mesh but capture hair using well placed splines that are also easily turned into polygon strips. Think of it as a way to block out hair in poly strips and save yourself some time drawing hair, or at the very least give yourself a base to draw on. You need to plot out your hair planes and be wise where you put the splines/planes. The standard high poly scalp method can't be used here, at least not well, which is what I think your problem is?
Also you can Convert the hair to a spline or a mesh and use the render to texture feature. However you still need to be smart about both meshes and standard RTT guidelines would apply. It is a good idea to render out a nice bump and spec map if you want but I wasn't going to drag the tutorial on longer than it is just to cover those tiny steps. The tutorial is a base to build off of and get people thinking about the hair/fur features in a different light.
Take him as an example:
See close hair. If the hair was lose than it could have any length and your method (which was also used in Gears of War btw
Planes are probably not the best solution here I think. So I make a "helmet" and want to bake my whole Hair onto that. In this case rendering the hair from different angels and then mixing together in ps doesnt give a convincing result at least not for me...
The method I outlined won't fit every hair style and is meant to create hair planes, not helmets. I'm sorry if I somehow lead to that conclusion. I mostly use it for medium to long hair types, mostly on females and for grass planes. Of course characters that work better with hair helmets should use that method.
Hopefully this tutorial made you aware of the hair/fur modifier and how easy it is to bang out several types of hair planes, quickly. I mostly wanted to draw awareness to the fact that it shouldn't be ignored because it is mostly used for high poly pipelines.
You could then render the nice hair onto a couple of the low poly mesh objects and then Uv the rest to match.
The eyebrows and hair in this image are done using ornatrix. I toyed with using them for the texture, but ended up only using the eyebrows. I made the hair into geometry, but planes, and then reduced the hair count till it was an acceptable level.
http://www.poopinmymouth.com/net/pcount/agust/hi_poly_06.jpg
I'm not sure we can use it for commercial use... Our lawyers are pretty twitchy about using free stuff.
Rick, yep it has a convert to mesh and spline feature and technically you can do short hair with it but it's been my experience that its faster to just sculpt it rather than mess with combing and styling.
I've been playing with the idea of writing a script that creates hair planes, based on underlying geo, presets, hair length etc. Got parts of it working but I'm bogged down at work at the minute.
It would be neat if you can turn each strand into a meta-blob and have them join into a hair helmet. I imagine developing and testing that would be a nightmare... The stands would have to be pretty thick and sparse to not kill max =/