Monday 26 June 2017

Texturing

Step 1 What is Texturing?

In 3d graphics, texturing means the process of creating and applying textures to the model. In fact, the term texturing consist of two things: UVW mapping and texture painting. UVW mapping was covered in my previous tutorial and this one will concentrate on the texture painting. We’re going to create the texture by using Photoshop and Viewport Canvas. Viewport Canvas is a 3D paint inside of 3ds Max. In the picture below you see the result of this tutorial.
Monster textured in 3ds Max 2011

Step 2 Mental Ray Renderer

We’re going to render the scene with Mental Ray. By default 3ds Max uses Scanline renderer so we have to change that. Change the renderer to Mental Ray ( Rendering > Render Setup… > Common tab > Assign Renderer > Production > mental ray Renderer ).

Step 3 Prepare the Model for Texturing

We continue from the unwrapping tutorial. As a starting point we should have the unwrapped model with the Turbosmooth modifier applied. We don’t need the checker material anymore so let’s get rid of that:
  1. Open Material Editor ( Press ‘m’ in keyboard ).
  2. Select a new (empty) material slot.
  3. Click “Get Material” button and select ( doubleclick ) ‘Arch & Design (mi)’ from the list ( Materials > mental ray > Arch & Design ).
  4. Assign the new material to the monster ( drag and drop ).
3D model in 3ds Max

Step 4 Texturing with Viewport Canvas

Viewport Canvas is a new feature in 3ds Max. I think it was introduced in 3ds Max 2010 and in 2011 it has been completely upgraded. If you don’t have 3ds Max 2011 you unfortunately can’t really follow this tutorial. If you have Photoshop, you could render a UVW template ( Unwrap UVW > Parameters > Edit… > Tools > Render UVW Template… ) and try to apply the ideas on top of that. Anyway, let’s launch Viewport Canvas and start painting.
  1. Select the monster model.
  2. Open Viewport Canvas ( Tools > Viewport Canvas… ).
  3. Click on the ‘Paint’ tool ( to activate the paint mode ).
  4. Select ‘Diffuse Color Map: …’ from the menu ( Viewport Canvas needs to know which map channel we’re painting.). A new dialog appears.
  5. Set the size of the texture map to 2000×2000.
  6. Select the folder for your file, name your file, and select PNG as file format ( I recommend choosing RGB 24 bit as color depth. Alpha channel is not needed. ).
  7. Click ‘OK’ to save the file.
Texturing with Viewport Canvas

Step 5 Starting Texture Painting

Let’s use the Fill and Gradient tools to give some color to our monster:
  1. Go to the front viewport.
  2. Select green color ( R103 G132 B58 ).
  3. Active the Fill tool and click on top of your monster.
  4. Open the Layers dialog ( Layers work just like in Photoshop ).
  5. Create and activate a new layer.
  6. Select dark green color (R44 G56 B24).
  7. Activate the Gradient tool. Click and hold on the bottom of the monster, drag upwards, and release when you’re satisfied with the gradient.
Texture painting in Viewport Canvas

Step 6 Saving the Texture

Deactivate the Gradient tool ( or whatever paint tool you have currently activated ). A new dialog appears. At the moment there are two layers but layers cannot be saved in a PNG file so something has to be done. There are several options and they are all pretty self-explanatory. We select ‘Save as PSD and replace texture in material’. I think that’s usually the most preferred choice. Now the file is saved as PSD and applied to the diffuse color channel in the material. You might wonder why we didn’t save the file as PSD in the first place. Unfortunately 3ds Max doesn’t allow that at the moment but I’m guessing it will change soon.

Step 7 Working with Photoshop

Next we’re going to work with Photoshop to create some texture:
  1. Open this file in Photoshop
  2. Desaturate the image ( Image > Adjustments > Desaturate )
  3. Apply ‘Palette Knife’ filter ( Filter > Artistic > Palette Knife… ). I used values ( 15, 3, 0 ). The idea is to have a painted look to the texture.
  4. The image size should be the same as our texture size in 3ds Max. Adjust if necessary.
  5. Save the file and return to 3ds Max.

Step 8 Apply the Texture to the Model

Let’s apply the texture to our model. You could do it in Photoshop but I’m using Viewport Canvas:
  1. Select the monster model.
  2. Open Viewport Canvas ( Tools > Viewport Canvas… ).
  3. Activate any paint tool ( to activate the paint mode ) and Open the ‘Layers Dialog’.
  4. Create and select a new layer
  5. Apply the texture we just created to the new layer ( In the Layers Dialog: File >Load Bitmap Into Current Layer… )
  6. Change the blending mode of the new layer to Overlay
  7. Change the opacity of the new layer to 35%
Viewport Canvas workflow
Tip: If the texture is displayed in low resolution go to the display driver settings and and maximize the resolution ( Customize > Preferences… > Viewports > Configure Driver… > Appearance Preferences > Download Texture Size > Match Bitmap Size as Closely as Possible ).

Step 9 Removing Texture Seams

Now the monster has a nice painted look but unfortunately the texture seams are clearly visible. Next we’re going to do something that would be really difficult in Photoshop but really easy in 3d paint. We’re going to use the Clone tool to paint over the seams:
  1. Activate the Clone tool.
  2. Orbit around the model to get a good view of a seam.
  3. Select suitable brush radius ( I recommend using a pretty large brush ). Tip: The shortcut to brush radius is CTRL + SHIFT + Left click & drag.
  4. Set the sampling point by positioning the pointer to suitable area on the monster and ALT-clicking.
  5. Paint over the seam.
  6. Use this method to remove all the seams. You must set the sampling point again several times until you are done. Convincing cloning takes usually some time. Experiment with the hardness of the brush as well.
Cloning seams

Step 10 Creating Details

Let’s create more details by adding another texture to our layer stack ( just like in step 6 ):
  1. Load this file.
  2. Create and select a new layer ( Make sure the new layer is the topmost layer. You can change their order by dragging and dropping ).
  3. Apply the texture to the new layer ( In the Layers Dialog: File >Load Bitmap Into Current Layer… )
  4. Clone the seams away
  5. Change the blending mode of the new layer to Overlay
  6. Change the opacity of the new layer to 30%
Now we have more small details in our texture. As you see this is very fast method of adding some random details to the surface. Now our diffuse map is complete. Next we’re going to create and apply texture maps to bump and reflection channels as well.

Step 11 Applying Reflection Color Map

Let’s apply a reflection color map to the material:
  1. In Viewport Canvas, deactivate any paint tool you might have active ( this is done to deactivate the paint mode).
  2. In Viewport Canvas, go to the ‘Options’ rollout and change ‘Paint On:’ from Diffuse Color Map to Reflection Color Map. A new dialog appears.
  3. Set the size of the texture map to 2000×2000.
  4. Select the folder for your file, name your file, and select PNG as file format ( I recommend choosing RGB 24 bit as color depth. Alpha channel is not needed. ).
  5. Click ‘OK’ to save the file.
Texture painting workflow

Step 12 Painting on the Reflection Color Map

Now there is a blank texture in the reflection color channel. In reflection color channel we paint matte areas with black and shiny/reflective areas with white. Let’s paint some drool:
  1. Activate the Paint ( brush ) tool.
  2. Select white color.
  3. Select rather large Radius ( CTRL + SHIFT + Right-click and drag. Suitable radius depends on the zoom level ).
  4. Make sure Hardness is set to zero.
  5. Open the ‘Layers Dialog’
  6. Create and select a new layer.
  7. Paint around the mouth to create some drool.
  8. Activate the Fill tool.
  9. Select black color.
  10. Select the Background layer
  11. Click on the model to paint it black. ( keep in mind that in the paint mode you see just the paint. The final reflection effect is seen only in rendering. )
  12. Deactivate the Fill tool ( to deactivate the paint mode ). A new dialog appears. Select ‘Save as PSD and replace texture in material’. Now the file is saved as PSD and applied to the reflection color channel in the material.
Painting reflection map

Step 13 Reflection Glossiness Map and Bump map

Let’s make the texture more interesting by adding a reflection glossiness map and a bump map:
  1. Open Material Editor ( Press ‘m’ in keyboard )
  2. Go to the ‘General Maps’ rollout and drag and drop the texture we just created from ‘Reflection Color’ to ‘Reflection Glossiness’. Select ‘Instance’ when asked.
  3. Go to the ‘Special Purpose Maps’ rollout and set the bump value to 0,05.
  4. Now we’re going to create the bump texture in Photoshop. Go to Photoshop and open the diffuse texture we created earlier (PSD).
  5. Make a duplicate of the diffuse texture ( Image > Duplicate… ).
  6. Close the original and work with the duplicate. Delete all layers except the one we created and applied in steps 7-8. Change the blending mode of the layer from Overlay to Normal and Opacity to 100. Save it as PNG file.
  7. Go back to 3ds Max and add the new file to the Bump channel ( Maps > Standard > Bitmap > bump.png ).
Creating material
Now the material is complete and we go on with the lighting and rendering.

Step 14 Lighting and Rendering Setup

We’re going to use a basic three-point lighting setup to illuminate the monster. Since this is essentially a texturing tutorial I’m not going to go through the lighting in detail but I’ll give you the exact settings you can use:
  1. Key light: Mental Ray Area Spot ( Create panel > Lights > Standard > mr Area Spot ).
    Intensity/Color/Attenuation > Multiplier: 1,5
    Area Light Parameters > Height: 200
    Area Light Parameters > Width: 200
  2. Rim Light: Mental Ray Area Spot ( Create panel > Lights > Standard > mr Area Spot ).
    Intensity/Color/Attenuation > Multiplier: 1,4
    Area Light Parameters > Height: 200
    Area Light Parameters > Width: 200
  3. Fill Light: Skylight ( Create panel > Lights > Standard > Skylight ).
    Multiplier: 0,4
    Sky Color: pure white
  4. Drool Light: Omni ( Create panel > Lights > Standard > Omni ).
    Advanced Effects > Diffuse: Off
Three point lighting
Let’s adjust the sampling settings to get a polished render. Go to the render setup and increase antialiasing quality by increasing Mental Ray’s sampling values ( Rendering > Render setup… > Renderer > Sampling Quality ):
  • Samples per pixel
    • Minimum: 4
    • Maximum: 64
  • Filter
    • Type: Mitchell ( For most scenes the Mitchell filter gives the best results. ).
Finally change the background color to black ( Rendering > Environment… > Common Parameters > Background > Color) and hit render. Below you see the final rendered image. I made some color correction in Photoshop as well:
  • Brightness: 40
  • Contrast: 20
Texturing tutorial
Thanks for reading!

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