blog.leocov.com

WIP–Judith Sketch

2012-05-14T18:45:00.001-04:00

Here it is. For now I’ll move onto something new

WIP–Judith

2012-05-04T19:11:00.001-04:00

working form this portion of Judith with the Head of Holofernes by Cristofano Allori

WIP - Felix Mendelssohn 2

2012-04-27T21:53:00.001-04:00

Time to move on.

WIP - Felix Mendelssohn

2012-04-26T20:16:00.001-04:00

work in progress – trying to get used to sculpting in Mudbox

working from this image:
(any one remember CGTalk’s 100 Heads post?)

lcRetopoBasic–Another Update

2012-02-25T11:59:00.001-05:00

Downloads

Some small changes based on requests

Removing a mesh from the High Res List will reset its display overrides such as x-ray and hidden
Added code to better handle Undo queue functionality when doing a shrink-wrap or relax
Adjusting the mesh layering effect with the slider will do so for all mesh’s in the list not just the selected one
Adding a new mesh to the High Res List will pop it to the currently active mesh layering distance
I disable Viewport 2.0’s vertex animation caching when the script is run – this fixes the problem of the mesh layering effect not updating when the viewport is rotated. Caching will NOT be automatically re-enabled.

lcRetopoBasic–UPDATE

2011-12-24T22:28:00.001-05:00

Downloads

Still BETA, but I’ve squashed some bugs and added some helpful features

Should deal with object names better, and namespaces from importing obj’s
Should no longer hang on occasion when relaxing or shrink wrapping
You can work in any selection mode, object, face, edge, vertex and use the Relax and Shrink-Wrap tools
Will keep your selection mode so you can continue editing components
Highlights the Object List red to remind you that you have no high-res selected

Still to do:
Viewport 2.0 should(?) offer some speed boosts, especially when working with large high-res objects, but the method for layering the high and low res geo doesn’t work properly in VP2.0. I need to come up with an updated method

Yes, Shadow Baking is delicious

2011-11-28T22:05:00.001-05:00

a short video demonstrating some progress on the shadow baking scripts for the lcShader. Its coming along well, and I will release a beta version at some point in the next few weeks.

lcReproject.cgfx–A Novel Texturing Technique

2011-10-27T22:52:00.001-04:00

Download

I was inspired by Brice Vandermoortele’s Normal Map Reprojection Shader and wanted to extend the idea to new uses. This is a novel way of texturing using lit sphere images and cubemaps. You can reproject color and normal textures to a new UV Set.

As a CGFX shader, only Nvidia cards will load this reliably, but I’ve added a arbfp1 technique that might work on AMD and older cards. Cubemaps are lower quality and don’t have any blurring using this mode.

Getting close . . .

2011-10-27T17:39:00.001-04:00

My new shader ‘lcShader’ is almost feature complete. It’s a very close approximation to the Mental Ray mia_material, but in real-time. In testing I’m able to get very realistic looking materials using a standard texture workflow (diffuse, spec, gloss, cubemap). Again, HLSL and CGFX versions will be identical, running the same exact code. Lights react much nicer than previous shaders and have realistic fall-off. And baked shadow maps too.

My shadow map baking script is also nearing completion, it will automatically link raytrace-baked shadow maps to the shader for linked lights and supports transparency in both the shader surface and the shadow cast.

Here is a quick screen grab, HLSL on the left, CGFX on the right. They don’t have the exact same shader settings so some slight differences

lcRetopoBasic–Maya Retopology Tool

2011-10-04T14:07:00.001-04:00

Downloads

I was inspired after seeing RetopoG, but since it is not currently available I decided to make my own tool for Maya.

This tool will let you use Maya’s makeLive features to easily draw new topology on a mesh. The tool is designed to be very simple and rely heavily on Maya’s built-in modeling tools. This is written in pyMel, which only comes pre-installed on Maya 2011 and later.

This is a very early beta-like version, I’ve only just begun to test this in the last few days but it seems workable. I don’t have any plans to include a full custom toolset like RetopoG, you will mostly have to use Maya’s tools.

A short video explaining the tool:

The Relax Verts and Shrink-Wrap Verts are tools based on Oleg Alexander’s oaRelaxVerts.mel

New Shader Tools Update

2011-09-17T16:22:00.001-04:00

I did some proof of concept work on the new shader and everything looks very positive. In order to broaden compatibility support I’m co-developing a CGFX and HLSL shader. They share most of their code by using #include files and are visually identical. This way people with AMD cards etc. wont be complete out of luck, although Shader Model 3.0 support will always be required.

Here is a quick screen grab, on the left is HLSL on the right CGFX.

Still a long way to go before the shader is feature complete, and the new pyMel UI is another matter.

This is a great time for Feature Requests, I have a ton of things planned, but I’m always open to suggestions.

New Shader Tools for Maya

2011-08-31T18:19:00.000-04:00

Congrats to Laurens Corijn and Robbert-Jan Brems on their XoliulShader 2 release, it looks amazing. They've noted that there will be only limited Maya support - so lets fill that void.

I'm going to update an entire new toolset for interacting with my CGFX shaders. Here is a preview UI layout. Very preliminary work. I have most of the functionality in place from other tools, just have to bring it together in one Monster release.

lcTextureSaver Extension

2011-08-29T22:34:00.001-04:00

I know some people were interested in this Photoshop extension tool, I wrote it for a very specific workflow we use at Turbine but if you find it useful all the better. I don’t have any plans to edit or modify the tool.

Download

Here is a quick intro video on installing and using the tool.

Some updates

2011-08-25T00:27:00.001-04:00

I’ve made some relatively minor updates to a few shaders, check the dates on the Downloads page. I like to keep things fluid and make rapid changes back and forth. Hopefully I’ll get some time to do a major pass on the Uber and Skin shaders soon.

I posted download links to a tool I made to simplify texturing at work a bit. the lcTextrueSaver is an extension for Photoshop CS4 and 5 that creates a custom folder structure for your PSD and uses that structure to save out RGB+A ‘combinations’ such as Diffuse+Clip, Normals+Specular, etc. It’s a tool mostly set up for the way we do texturing at my job but if you find it useful or inspiring run with it.

As a note on installing Photoshop extensions, make sure you run the Adobe Extension Manager as an Administrator in Windows. (Also I never test this stuff out on Mac so good luck to you guys)

I’ve been doing a lot of pyMel development, I’ll get around to releasing updated tools with these new skills.

lcShaderTools.mel–v2.3

2011-05-25T10:16:00.001-04:00

Download

Updated to let you interact with my new CGFX shaders featuring point lights.

lcAMDShader.cgfx – compromise shader for AMD graphics cards

2011-03-06T17:31:00.001-05:00

EDIT (03/24/2011) – Seems even with my bests attempts although the shader ‘runs’ on AMD cards, normal maps don’t show up. I’m taking the download offline until I can do more testing and hopefully fix the issue.

CGFX in Maya and AMD graphics cards seem to get along very poorly – most often they simply will not work together. CGFX offers a large number of ‘profiles’ under which to compile shaders at runtime and only the arbfp1 and arbvp1 profiles seem to work reliably.

I’ve put together a cut down version of my lcUberShader so that it will run under the arbfp1/arbvp1 profiles. This means that I’ve had to remove a lot of features, for example there are only 2 lights supported, 1 directional and 1 point light. There are no cubemaps supported and currently no glow/incandescence map (although I hope to fit it in at a later time). Also, rendering in the hardware render buffer seems to have problems in the 8-bit alpha mode. But many of the features remain intact and it seems to work well.

I don’t have AMD hardware to test this on but hopefully some of you can give me your feedback.

I’m investigating whether the glslf/glslv profiles could work on AMD hardware, but its not certain. With any luck Maya 2012 will have a new CG compiler and provide better AMD support.

lcUberShader_2.7.cgfx

2011-02-28T21:03:00.001-05:00

Download

Seems that I had uploaded the incorrect version, this is now fixed. 2.7 uses gp4vp and gp4fp profiles.

Updated lcShaders to gp4vp / gp4fp

2011-02-24T21:35:00.001-05:00

lcUberShader, lcSkinShader
version 2.7 – Download Page

I have updated my lcUberShader and lcSkinShader to run on the gp4vp and gp4fp profiles instead of vp40 and fp40 as this removes some restrictions on the number of temporary registers available and allows for more complicated, math intensive shaders. The lcUberShader suffers only a minor performance penalty but the lcSkinShader seems to run at 1/2 to 1/4 the speed compared to the old profile. I’ll have to investigate the issue but I’m not focused on speed with these shaders.

On the plus side they both now have 3 directional lights and 3 point lights and I’ll expand the features in the near future to include baked shadow map functionality for the point lights as well.

I’ve only done preliminary testing so let me know if you run into issues.

lcUbershader Point Lights

2011-02-23T23:15:00.001-05:00

version 2.6 – Download Page

I’ve added 3 point lights in addition to the 3 directional lights to the lcUbershader. These point lights also have an attenuation property, so as they move away from an object their intensity decreases, there is a multiplier to adjust this effect.

I’m not quite sure what will happen with the baked shadows, currently only active for the directional lights, I will probably add the option for the point lights at a future time.

I haven’t had the time to test this change extensively so let me know if something is not working right.

I’m working on adding the point lights to the lcSkinShader also, but I hit the registers limit (32) for the fp40 profile so I’ll have to break things up into more passes or remove some features.

Updated Uber and Skin Maya Shaders

2011-01-09T15:28:00.001-05:00

versions 2.3 – available here: Download Page

Added 2 new texture inputs
a mask to remove rimlighting from unwanted areas
a mask for the cubemap reflection, for example to isolate metal bits

I changed the way back face shading is done – instead of using the faceforward() function to invert the normals (as this causes some shading errors along the silhouette), I am now doing a 2 pass method. A pass is rendered for the back faces and a second pass for the front faces is layered on top. This is much more expensive as the geometry is rendered twice but you get perfect results.

Thanks to Richard Smith for the feedback leading to these updates.

Maya Realtime Shaders – Big Update

2010-09-07T00:29:00.003-04:00

Up to date downloads are available here: Download Page
I’ve been reading alot of technical papers and was inspired to rewrite and double check all my shaders. First, some things were broken for example, ambient color was not doing what its supposed to do. Second, I finally understood the whole linear-lighting thing and all my rgb inputs have been appropriately gamma corrected. With linear lighting, tonemapping and exposure become much more useful, so I implemented a simplified version of the Uncharted 2 “film-tonemap curve”. Third, I wanted to make it easier to do rewrites and maintain the code, so i switched the way I was working with multiple lights and inspired by rsl illuminace loop am now doing my lighting through a loop. This means I can change the code without having to worry about the number of lights or keeping track of their variables and passing them to all needed functions. I only have to initialize an array to hold that information.
lcUberShader.cgfx and lcNextGenShader.fx are now visually the same although slight differences in the languages are apparent in the code. I still recommend using cgfx over hlsl for Maya.
lcSkinShader.cgfx and lcHairShader have few changes beyond linear math option and code style changes. Some attributes have been removed or rearranged - especially with the lcSkinShader, old posts with attribute descriptions may no longer apply.
lcLitSphere.cgfx is an implementation of matcap/lit sphere shading – just for fun and in case anyone is interested.
Pictures: (click for larger)

lcMrBatchBake.mel – Mental Ray for Maya Texture and Vertex Baking

2010-08-26T23:49:00.002-04:00

Download - Updated – 08/27/2010
Script: lcMrBatchBake.mel
Icon: lcMrBatchBake.bmp

NOTE: Apparently this script doesn't work on the Mac, I don't have one to test with so you guys are out of luck sorry.'

Now you have the option to bake vertex color as well as texture maps. This is great for baking ambient occlusion to vertices for game models. I also consolidated and simplified a lot of the code. Plus now its colorful!

lcSkinShader.cgfx – Maya Realtime Skin Shader

2010-08-21T17:26:00.001-04:00

Download: lcSkinShader.cgfx (save as)

Another cool shader – inspired by the Siggraph 2010 presentation 'Uncharted 2: Character Lighting and Shading' by John Hable. Its a great presentation and offers a lot of insight on how to create realistic SSS effects in shader. Unfortunately, the main topic – blurred render targets – is not possible in Maya, but the secondary techniques presented, Bent Normals and Blended Normals, are doable in Maya.

This shader takes the Blended Normals approach and adds some other elements, such as a reddish edge to the diffuse falloff, as well as uses 2 specular highlights. Also the paper describes how the Blended Normals technique results in a blue/red coloration, and the blue is not as desirable as the red, so I have implemented a very basic cyan suppression as well.

Here is a comparison with Lambert diffuse and my SSS effect (exaggerated for emphasis):

Again, a lot of attributes, but the key SSS ones are:

SSS Blended Normal Intensity – this controls the main effect of the blended normals.

SSS Edge Color – this is the color along the Diffuse Shading edge

SSS Edge Radius – this is the size of the Diffuse Shading edge coloration

SSS Edge Exponent – another tweakable parameter to adjust the reddish edge

Specular Normals Intensity – because the blended normals technique can ‘lessen’ the impact of the normal map, but overdriving the normal map intensity on the diffuse can look bad, this only overdrives the normal map on the specular highlight. Can help bring back detail.

The shadowMap and AO parts are the same as my lcHairShader.cgfx.

lcHairShader.cgfx – Maya Realtime Hair Shader

2010-08-19T23:35:00.003-04:00

Download: lcHairShader.cgfx (save as)
Updated:
08/21/2010 – fixed some problems with the shadowMap texture and AO texture and vertex color code.
This one is pretty cool – I’ve been reading some of the papers coming out of Siggraph and one by the Uncharted 2 Team referenced an old 2004 paper called “Practical Real-Time Hair Rendering and Shading” by Thorsten Scheuermann. Its a really great paper and I decided to make a cgfx implementation of its hair technique for Maya. The paper is interesting because it offers a single purpose anisotropic highlight function that is specially designed for hair – using no normal maps, the only real required map is a specular map to jitter the highlight and create the ‘strands’ effect.
My Maya shader is much expanded and has a lot of functions from my previous shaders as well as some new things. Its a very versatile hair shader – although it tends to lend itself more to stylized looks than photorealism.
NOTE: Hair UV shells should all be aligned vertically – highlight orientation is based on the UV shell alignment.

There are a ton of attributes, but some of the more interesting ones are:
Main UV Texture Tiling – tiling is useful on main diffuse and specular textures to sort of set the size of the hair strands – normal map can be excluded from tiling
Hair Color – Multiplied by diffuse map – diffuse map can be B&W or colorized if you set hair color to white.
Spec Edge Sharpness – hardens the specular highlight to make it look shinier/slicker
Specular Highlight Shift – moves the highlight up and down the surface
Specular Noise Map Scale – controls the intensity of the specular jitter effect
AO in vertex color – you can bake AO into the vertex color – multiplies by the Ambient and Diffuse
Shadow Map – r is shadow for light 1, g is shadow for light 2, b is shadow for light 3, a (alpha) is AO

Texture Examples:
diffuse (multiply by hair color) – alpha is hair transparency
normal map (for big waves)
specular highlight jitter (this is normal map alpha channel)

Maya - Create a Cubemap

2010-07-30T11:01:00.013-04:00

This is inspired from my participation on a recent Polycount thread.

Its pretty straight forward to make your own cubemaps from Maya, you just need 6 cameras rotated around a shared point. The cameras each render out a square image representing one of each side of the cube. You can easily stitch these images together using an interactive program like ATI's CubeMapGen for realtime use, or build out a cube-cross in Photoshop. You just have to take care as to the placement and rotation of the images in the stitch.

There is one trick to this in Maya; although its pretty intuitive to set the Angle of View of the cameras to 90 degrees, you also have to set the Camera Aperture x and y to 1.0.

You are not restricted to staying in the cubemap format either, just run the result through HDRShop and you can convert to a variety of other formats like latlong and angular probe.

Here is a test image from CubeMapGen showing that the cubemap is seamless (some minor blurring in the reflection of the sphere is actually due to the realtime shader in the viewport and not sampling issues in the textures).

Download Test Scene (Z axis are inverted compared to Maya because thats what CubeMapGen expects)

cubemap_maker.ma