look-dev

Colorway in VFX - chapter 2 /  by Xuan Prada

A few days ago I did my first tests in Colorway. My idea is to use Colorway as texturing and look-development tool for VFX projects.

I think it can be a really powerful and artist friendly software to work on different type of assets.
It is also a great tool to present individual assets, because you can do quick and simple post-processing tasks like color correction, lens effects, etc. And of course Colorway allows you to create different variations of the same asset in no time.

With this second test I wanted to create an entire asset for VFX, make different variations and put everything together in a dailies template or similar to showcase the work.

At the end of the day I'm quite happy with the result and workflow combining Modo, Mari and Colorway. I found some limitations but I truly believe that Colorway will fit soon my needs as Texture Painter and Look-Dev Artist.

Transferring textures

One of the limitations that I found as Texture Painter is that Colorway doesn't manage UDIMs yet. I textured this character time ago at home using Mari following VFX standards and of course, I'm using UDIMs, actually something around 50 4k UDIMs.

I had to create a new UV Mapping using the 1001 UDIM only. In order to keep enough texture resolution I divided the asset in different parts. Head, both arms, both legs, pelvis and torso.
Then using the great "transfer" tool in Mari, I baked the high resolution textures based on UDIMs on to the low resolution UVs based on one single UV space. I created one 8k resolution texture for each part of the asset. I'm using only 3 texture channels, Color, Specular and Bump.

Layer Transfer tool in Mari.

All the new textures already baked in to the default UV space 1001

My lighting setup in Modo couldn't be more simple. I'm just using an Equirectangular HDRI map of Beverly Hills. This image is actually shipped with Modo.
Image Based Lighting works great in Modo and is also very easy to mix different IBLs in the same scene. Just works great.

Shading wise is also quite simple. Just one shading layer with Color, Specular and Bump maps connected. I'm using one shader for each part of the asset.

The render takes only around 3 minutes on my tiny MacBook Air.
Rendering for Colorway takes more than that but obviously you will save a lot of time later.
Once in Colorway I can easily play with colours and textures. I created a color texture variation in Mari and now in Colorway I can plug it and see the shading changes in no time.

All the different parts exported from Modo are on the left side toolbar.

On the right side all the lights will be available to play with. In this case I only have the IBL.

All the materials are listed on the right side. It is possible to change color, intensity and diffuse textures. This gives you a huge amount of freedom to create different variations of the same asset.

I really like the possibility of using post-precessing effects like Lens distortion or dispersion. You can have a quick visual feedback of very common lens effects used on VFX projects.

Finally I created a couple of color variations for this asset.

Notes

A couple of things that I noticed while working on this asset:

  • I had one part of the asset with the normals flipped. I didn't realize of this and when rendering for Colorway, Modo crashes. Once inverted the normals of that part, it never crashed again.
  • It would be nice to store looks, or having the option to export looks from one project to another one. Let's say that I'm working only on the upper part of the character, render for Colorway and create some nice looks (including effects like lens distortions, color corrections,etc). It would be great to keep that for the next time that I export the whole character to Colorway.

Colorway for Look-Development in VFX /  by Xuan Prada

A few days ago (or weeks) The Foundry released their latest cool product called "Colorway", and they did it for free.

Colorway is a product created to help designers with their work flow specially when dealing with color changes, texture updates, lighting, etc. Looks in general.
This software allow us to change those small thing once the render is done. We can do it in real time without waiting long hours for rendering again. We can change different things related with shading and lighting.

This is obviously quite an advantage when we are dealing with clients and they ask us for small changes related with color, saturation, brightness, etc. We don't need to render again anymore, just use Colorway to make those changes live in no time.
Even the clients can change some stuff and send us back a file with their changes.

Great idea, great product.

I'm not a designer, I'm a vfx artist doing mainly textures and look-development, and even if Colorway wasn't designed for vfx, it can be potentially be used in the vfx industry, at least for some tasks.

There are a few things that I'd like to have inside Colorway in order to be a more productive texturing&look-dev tool, but so far it can be used in some ways to create different versions of the same asset.

To test Colorway I used my model of War Machine.

  • Colorway allow us to render an asset using a base shader. Later we can apply different versions of the same textures, or just flat colors.
  • It all begins inside Modo (Cinema4D is on it's way).
  • It's very important how you organize your asset and shaders inside Modo. If you want to have a lot of control in Colorway you will have to split your scene in different parts.
  • In this example, I separated the head in different parts, so I can select them individually later on in Colorway.
  • Even if I'm using the same shader for the whole head, I made different copies so I can tweak them one by one if I want to have even more control in Colorway.
  • In Modo work on the look as you usually do. Once you are happy with the results export to Colorway.
  • In this case I'm using textures to create the look. Maybe you can do it without textures and apply them later in Colorway. You will be able also to remove all the textures in Colorway and start from scratch there. This is a personal taste.
  • Once happy just click on the Colorway button.
  • You can export all the materials and lights used in the scene or only those selected.
  • Click on the render button and that's it.
  • Once the render is done, just open the file exported from Modo and Colorway should pop up.
  • The workspace is super simple and well organized. There are selection groups and looks on the right and shaders, lighting and effects on the left.
  • Just select one of the parts on your left, one of the shaders on your right, or simply select in the viewport.
  • Automatically the controls for the material will pop up.
  • In the material options you can change the textures used by the shaders, or remove them if you want to start with a flat color.
  • I'm changing here the textures for just one of the materials, and later for all of them, creating a new version of my asset.
  • As I said before we can remove all the textures and use only the base shaders plus flat colors in order to create a new version of the asset.
  • Finally the versions that I created for this post :)

A few things that I'd like to see in Colorway in future versions in order to have more control and power for look-dev tasks.

  • Right now we can only change RGB textures. It would be nice to have control over secondary maps. Blending textures with masks would be also great.
  • We can't control the shaders parameters. Having that control for look-dev would be amazing.
  • Support UDIMs has to be a must.
  • Not sure how Colorway manages IBL. If you are using different lights seems to be ok, but if using only IBL it doesn't seem to work totally fine.
  • Transparency, glow and other shading options don't work in the current version.

Mari to Modo with just one click /  by Xuan Prada

UDIM workflow has been around for the last 10 years or so. It became more popular when Mari came out and these days it’s being used by everyone in the vfx industry.

In this blog you can find different ways to setup UDIMs in different software and render engines.
With Modo 801 has never been so easy, fast and great!
With just one click you are ready to go!

  • Export your textures from Mari. I always use the naming “component_UDIM.exr” “RGB_1001.exr”
  • Once in Modo, assign a new shader to your asset.
  • Add a new layer with a texture map, as usual. Add layer -> image map -> load udims.
  • Select the UDIM sequence that you exported from Mari.
  • Change the “effect” to point to the desired shader channel.
  • By default Modo enables the option “use clip udim”. You can check this in the “uv” properties. This means that you don’t need to do anything, Modo will handle the UDIM stuff by itself.
  • That’s it, all done :)
  • As an extra, you can go to the image manager, select one single map and check the UDIM coordinate.
  • Another cool thing, is that you can select all the UDIM sequence in the imagen manager, and change the color space with one single click! This is great if you are working with linear workflow or another color space.

Vector displacement in Modo /  by Xuan Prada

Another quick entry with my tips&tricks for Modo.
This time I’m going to write about setting up Mudbox’s vector displacements in Modo.

  • Check your displacement in Mudbox and clean your layer stack as much as you can. This will make faster the extraction process.
  • The extraction process is very simple. Just select your low and high resolution meshes.
  • Set the vector space to Absolute if you asset is a static element, like props or environments.
  • Set the vector space to Relative if your asset will be deformed. Like characters.
  • Always use 32 bit images.
  • As I said export the maps using EXR 32 bits.
  • Before moving to Modo or any other 3D package, check your maps in Nuke.
  • Once in Modo, select your asset and go to the geometry options.
  • Check Linear UVs and set the render subdivision level.
  • Assign a new shader to your asset.
  • Add a new texture layer with your vector displacement map.
  • Set it up ass Displacement Effect.
  • Set the low and high value to 0 and 100.
  • You will see a displacement preview in viewport.
  • Set the gamma to 1.0 Remember that 32bit images shouldn’t be gamma corrected using Linear Workflow.
  • In the shader options set the Displacement Distance to 1m this should give you the same result than Mudbox.
  • In the render options you can control the displacement rate, which is your displacement quality more or less.
  • 1.0 is fine, play with that. Lower values will give you sharper results but will need more time to render.
  • Finally render a quick test to see if everything looks as expected.

Zbrush displacement in Modo /  by Xuan Prada

Another of those steps that I need to do when I’m working on any kind of vfx project and I consider “a must”.
This is how I set up my Zbrush displacements in Modo.

  • Once you have finished your sculpting work in Zbrush, with all the layers activated go to the lowest subdivision level.
  • Go to the morph target panel, click on StoreMT and import your base geometry. Omit this step if you started your model in Zbrush.
  • Once the morph targer is created, you will se it in viewport. Go back to your sculpted mesh by clicking on the switch button.
  • Export all the displacement maps using the multi map exporter. I would recommend you to use always 32bit maps.
  • Check my settings to export the maps. The most important parameters are scale and intensity. Scale should be 1 and intensity will be calculated automatically.
  • Check the maps in Nuke and use the roto paint tool to fix small issues.
  • Once in Modo, import your original asset. Select your asset in the item list and check linear uvs and set the amount of subdivisions that you want to use.
  • Assign a new shader to your asset, add the displacement texture as texture layer and set the effect as displacement.
  • Low value and high value should be set to 0 and 100.
  • In the gamma texture options, set the value to 1.0
  • We are working in a linear workflow, which means that scalar textures don’t need to be gamma corrected.
  • In the shader options, go to the surface normal options and use 1m as value for the displacement distance. If you are using 32bit displacements this value should be the standard.
  • Finally in the render options, play with the displacement rate to increase the quality of your displacement maps.
  • 0.5 to 1 are welcome. Lower values are great but take more time to render, so be careful.
  • Render a displacement checker to see if everything works fine.

Multi UDIM workflow in Modo /  by Xuan Prada

You know I’m migrating to Modo.
Multi UDIM workflow is on my daily basis tasks, so this is how I do the setup.

  • First of all, check textures and UDIMs in Mari and export all the textures.
  • Check the asset and UVs in Modo.
  • Load all your textures in the Modo’s image manager.
  • Create a new material for the asset.
  • Add all the UDIM textures as image layers for each required channel.
  • In the texture locator for each texture change the horizontal repeat and vertical repeat to reset. And change the UV offset. It works with negative values (not like Softimage or Maya).
  • That’s it. Make a render check to see if everything works fine.

Arm texture breakdown /  by Xuan Prada

I did a simple and quick texture breakdown for an human arm.
These are the textures that I usually create when I need to texture digital doubles for films or any kind of humanoid character.

These are the most basic textures used.
Usually working on movies we need more additional textures depending on render engines, other pipeline tools or artistic decisions.
But as I said, take this example as a base or starting point for your work.

These are quick renders using a neutral lighting rig for look-dev.

Diffuse textures.

Overall textures.

Scatter textures.

Displacement textures.

Fine displacement textures.

Specular textures.

Zbrush displacement in V-Ray for Maya /  by Xuan Prada

It is always a bit tricky to set up Zbrush displacements in the different render engines.
If you recently moved from Mental Ray or another engine to V-Ray for Maya, maybe you should know a few things about displacement maps extracted from Zbrush.

I wrote down here a simple example of my workflow dealing with that kind of maps and V-Ray.

  • First of all drag and drop your 16 bits displacement to the displacement channel inside the shading group attributes.
  • Maya will create a displacement node for you in the hypershade. Don’t worry to much about this node, you don’t need to change anything there.
  • Select your geometry and add a V-Ray extra attribute to control the subdivisions and displacement properties.
  • If you exported your displacement subdividing the UV’s, you should check that property in the V-Ray attributes.
  • Edge lenght and Max subdivs are the most important parameter. Play with them until reach nice results.
  • Displacement amount is the strength of your displacement and displacement shift sould be half negative than your displacement amount if you are using 16 bits textures.
  • If you are using 32 bits .exr textures, the displacement shift should be 0 (zero).
  • Select your 32 bits .exr file and add a V-Ray attribute called allow negative colors.
  • Render and check that your displacement is looking good.
  • I’ve been using these displacement maps. 16 bits and 32 bits.

Vray sss test /  by Xuan Prada

Just testing Vray’s SSS shader for realistic skin look-dev purposes.
I ended with the theory that would be quite simple to set-up a nice, realistic and cheap SSS shader for human and creature assets. I love the raytraced solid scatter, but with complex models I can’t get rid of some of the artifacts in the SSS channel.
I will post more quite soon.

  • To achieve better results, I like to combine SSS shaders with Vray Mtl shaders which have better solutions for speculars and reflections. With this method the reflection of the surface is controled by BRDF instead of the poor spec control of the SSS shader.

Texturing for VFX film projects. Case study /  by Xuan Prada

These are the key points of an introduction lecture which I gave about texturing for VFX film projects.
We used different assets on the class but this is the only one which is not copyrighted and I can show here.
I created this asset specifically for this course.

Summary

- Check the model.
- Render a checker scene.
- Decide about the quality needed for the textures. Is it a hero asset?
- UV mapping.
- Organization methods.
- How many UDIM’s?
- Photo Shoot.
- What kind of lighting do I need?
- Accessories. (Color checkers, tripod, polarized filters, angular base, etc).
- Bakes. (dirt maps, dust maps, UVs, etc).
- Grading reference images. Create presets.
- Clean reference images for projections.
- Create cameras and guides in Maya/Softimage for projections.
- Adapt graded and cleaned reference images for projection guides.
- Project in 3D software or Mari. (Mari should be faster).
- Work on the projections inside Mari. (We can use Photoshop, Mari or both of them. Even Nuke).
- Create  a 16 bits sRGB colour textures.
- Test colour channel in the light rig.
- Create a 16 bits gray scale specular textures.
- Create a 16 bits gray scale bump textures.
- Create a 16 bits gray scale displacement textures.
- Create a 8 bits gray scale ISO textures.
- Look-Dev blocking.
- Import the light rig.
- Create a basic pass.
- Checker render (matte).
- Checker render (reflective).
- Create clusters.
- Block materials.
- Look-Dev primary.
- Set up diffuse.
- Set up specular and reflections.
- Balance materials.
- Look-Dev secondary.
- Set up bump.
- Set up displacement.
- Rebalance materials.
- Set up ISO’s.
- Look-Dev refinement.
- Rebalance materials if needed.
- Create material libraries.
- Render turntables.

Basic displacement in RenderMan /  by Xuan Prada

  • Select the object’s shape node in the Attribute Editor and then go to Attribute -> RenderMan -> Add Sudvision Scheme. This will create a smooth surface.
  • Load your displacement texture in the Hypershade.
  • Play with the Alpha Gain and Alpha Offset to scale the image.
  • Alpha Offset should be half negative than Alpha Gain. So if Alpha Gain is 2 Alpha Offset should be -1
  • Drag the displacement texture on to the displacement material in the shading group attributes.
  • This will create a displacement node.
  • Select the displacement node and go to Attributes -> RenderMan -> Add Displacement Attribues.
  • Set the displacement bound to something similar to your highest displacement value.
  • If you are using ray trace rendering you need to add ray traced attributes to your displacement.
  • Select your shape node and go to Attribute -> RenderMan -> Manage attributes and select TraceDisplacement.
  • Turn the shading rate down to increase the quality of your displacement. You can add a RenderMan attribute to control this instead change the global render options, you’ll save a lot of render time.

Linear Workflow in Maya with Vray 2.0 /  by Xuan Prada

I’m starting a new work with V-Ray 2.0 for Maya. I never worked before with this render engine, so first things first.
One of my first things is create a nice neutral light rig for testing shaders and textures. Setting up linear workflow is one of my priorities at this point.
Find below a quick way to  set up this.

  • Set up your gamma. In this case I’m using 2,2
  • Click on “don’t affect colors” if you want to bake your gamma correction in to the final render. If you don’t click on it you’ll have to correct your gamma in post. No big deal.
  • The linear workflow option is something created for Chaos Group to fix old VRay scenes which don’t use lwf. You shouldn’t use this at all.
  • Click on affect swatches to see color pickers with the gamma applied.
  • Once you are working with gamma applied, you need to correct your color textures. There are two different options to do it.
  • First one: Add a gamma correction node to each color texture node. In this case I’, using gamma 2,2 what means that I need to use a ,0455 value on my gamma node.
  • Second option: Instead of using gamma correction nodes for each color texture node, you can click on the texture node and add a V-Ray attribute to control this.
  • By default all the texture nodes are being read as linear. Change your color textures to be read as sRGB.
  • Click on view as sRGB on the V-Ray buffer, if not you’ll see your renders in the wrong color space.
  • This is the difference between rendering with the option “don’t affect colors” enabled or disabled. As I said, no big deal.

Mari to Softimage /  by Xuan Prada

Recently I was involved in a master class about texturing and shading for animation movies, and as promised I’m posting here the technical way to set-up different UV sets inside Softimage.
Super simple process and really efficent methodology.

  • I’m using this simple asset.
  • These are the UVs of the asset. I’m using different UV sets to increase the quality. In this particular asset you can find four 4k textures for each channel. Color, Specular and Bump.
  • You probably realized that I’m using my own background image in the texture editor. I think that this one is more clear for UV mapping than the default one. If you want you can download the image, convert it to .pic and replace the original one located on C:\Program Files\Autodesk\Softimage 2012\Application\rsrc
  • This is the render tree set-up. Four 4k textures for color, specular and bump. Each four textures are mixed by mix8color node.
  • Once everything is connected, you still need to offset each image node to match the UV ranges.
  • I know that the UV coordinates in Softimage are a bit weird, so find below a nice cart which will be so helpfull for further tasks.
  • Keep in mind that you should turn off wrap U and wrap V for each texture in the UV editor.
  • Really quick render set-up for testing purposes.

Faking SSS in Softimage /  by Xuan Prada

SSS is a very nice shader which works really great with a good lighting setup, but sometimes  is so expensive shader when you´re using Mental Ray.
Find below a couple of tecniques to deal better with SSS. Just keep in mind that those tricks could improve your render times a bit, but never will reach the same quality than using SSS for itself.

  • I’m using this simple scene, with one key light (left), one fill light (right) and one rim light.
  • A SSS compound is connected to the material surface input, and the SSS_lightmap (you can find that node in the render tree -> user tools) connected to the lightmap input of the SimpleSSS. And then, the Simple SSS lightimap connected to the material lightmap input.
  • Write the output and resolution of your lightmap.
  • Hit a render and check the render time.
  • Disconnect the lightmap.
  • Render again and check the render times as well. We have imprpved the times.
  • If you need to really fake the SSS and render so fast, you can bake the SSS to texture using RenderMap, but keep in mind that the result will be much worst than using SSS. Anyways you can do that for background asset or similar.
  • Now you can use another cheaper shader like blinn, phong or even constant with your baked SSS.
  • As you can see the render is now so fast.

Dealing with normal maps in Softimage /  by Xuan Prada

Yes I know, working with normal maps in Softimage is a bit weird sometimes, specially if you worked before with 3D Max normal+bump preset.

I’ve been using the same method over the years and suited fine for me, maybe would be useful also for you.
I prefer to generate the normal maps inside Softimage rather than Mudbox or Zbrush, usually works much better according to my tests with different assets.

  • So, you should import in the same scene both geometrys, high and low. Don’t be afraid of high poly meshes, Softimage allows you to import meshes with millions of polygons directly from Mudbox or Zbrush.
  • With both meshes in your scene be sure that they are perfectly aligned.
  • Check the UV mapping of the low resolution mesh.
  • Select the low resolution mesh and open the ultimapper tool.

- The most important options are:

  • Source: You have to click on your high resolution mesh.
  • Path: Where your normal map texture will be placed.
  • Prefix: A prefix for your texture.
  • Type: You can choose between different image formats.
  • Normal in tangent space: The most common normal map type.
  • Resolution: Speaks for itself.
  • Quality: Medium it’s fine. If you choose high the baking time will increase a lot.
  • Distance to surface: Click on Compute button to generate this parameter.
  • Click on generate and Softimage will take some time to generate the normal map.
  • The normal map is ready.
  • Hide your high resolution mesh.
  • Grab one of the MR shaders and drag it to your mesh.

- Use a normal map node connected to the bump map input of the shader.

  • Choose the normal map generated before.
  • Select the correct UVs.
  • Select tangents mode.
  • Uncheck unbiased tangents.
  • Hit a render and you’ll see you normal map in action.
  • Cool. But now one of the most common procedures is combining a normal map with a bump map.
  • I’m using the image above.
  • If you use a bump map generator connected into the bump map input you will have a nice bump map effect.
  • Find below the final render tree combining both maps, normal and bump.
  • The first bump map generator has two inputs, color matte which is a plain white color and the normal map with the options which I already commented before. Be sure to select relative to input normal in the base normal option of the bump map generator.
  • The second bump map generator is your bump texture where you can control the intensity increasing or decreasing the factor value.
  • The vector math vector node allows you to combine both bump map generators.
  • Connect the first bump map generator  to the first input and the second one to the second imput.
  • In the operation option select vector input1 + vector input2.
  • Final render.

Inverted occlusion in 3D Max /  by Xuan Prada

People asked me for a step by step installation and usage of Binary Alchemy Color Ray Length shader in 3D Max.
Here we go.

Installation

  • Download BA Shaders for 3D Max.
  • Copy .dll files here -> “3ds Max 2010\mentalray\shaders_3rdparty\shaders”
  • Copy .mi files here -> “3ds Max 2010\mentalray\shaders_3rdparty\include”
  • Edit “3rdparty.mi” located here -> 3ds Max 2010\mentalray\shaders_3rdparty
  • Your “3rdparty.mi” must be something like this.

Usage

  • Create a matte/shadow shader and uncheck “receive shadows” and “use ambient occlusion”.
  • In the “camera mapped background” input, connect a “BA_color_raylength” shader.
  • Play with the “spread” to control the behaviour of the occlusion.
  • Once rendered you’ll have something similar to this.
  • Mix the “BA_color_raylength” with procedural maps or bitmaps to improve the result.

Edit: The most important parameters to play with are “spread” and “far output”.

Inverse dirt maps /  by Xuan Prada

Sometimes is very useful to generate inverse occlusion bakes to reach an interesting starting point to paint our dirt maps.
Vray dirt material is perfect for this goal, but if you don’t work with Vray, is very easy to do the same with Mental Ray and Binary Alchemy Shaders.

  • You need to install the Binary Alchemy Shaders. Some packages are free and you will have to pay for another ones.
  • Apply a “surface shader” to the object and connect a “BA_color_raylenght” to it.
  • Put this shader in “Inverted Normal” mode and play with his parameters.
  • We get an inverted “ambient occlusion”.
  • Use a “blend colors” , “layered shader” o similar to combine this inverted occlusion with a nice bitmap.