marcus_civis
09-30-08, 11:00 AM
MatCap012.jpg
The heart of a MatCap is its texture map - shown in the little icon at the bottom of the Material Modifiers. You'll see it has one or two spheres; these images provide the 'light map' which gives the material its lighting direction and color.
Sometimes you might want to change an existing MatCap rather than start from scratch with a new one. Here is one method that you can try.
1. First load the PolySphere ztool from the ZTools folder and divide until it is smooth. Make sure that it has UVs enabled. Create a new texture map of 1024 x 1024.
2. With your MatCap selected, draw the PolySphere on the canvas and enter Edit mode.
3. Make sure Perspective is OFF and then drop the model into Projection Master ('G').
MatCap001.jpg
4. Now go to the Layer palette and press 'Bake'. The B Blend slider should be set to 100.
MatCap002.jpg
5. Pick up from Projection Master, making sure only COLORS, DOUBLE-SIDED and FADE are selected. Most likely the PolySphere will now look rather dark and messy. To see the texture map properly press Render: Flat.
MatCap003.jpg
6. If you rotate the PolySphere you will see that the MatCap lighting and color has been transferred to the texture. There will be a seam which you can paint over if you want by dropping again into Projection Master and using the Clone and Smudge brushes.
MatCap004.jpg
7. Rotate the PolySphere until the light direction is as you want. Mark the position (press the M+ button in the Marker palette) so you can redraw the sphere if you need to.
MatCap007.jpg
8. With the PolySphere in Edit mode, make sure Preview Render is on and select the Fast Shader material. This will mean that the sphere will react to ZBrush's lights. Adjust the Ambient and Diffuse sliders so that the result is not too dark - I used 50 and 80.
MatCap008.jpg
9. Set up additional lights in the Light palette if you wish. For colored lights you will need to press Best Render (though you may not need to render with Shadows on).
MatCap009.jpg
10. When you are happy with the result use the MRGBZGrabber ztool to capture the texture.
MatCap010.jpg
11. Some MatCaps have two spheres in the texture map. You can add a second sphere to the new texture automatically using the MRGZGrabber. After setting up the second sphere, reselect the MRGBZGrabber and check that your new texture is selected in the Texture palette, then hold down the Ctrl key and grab the sphere.
MatCap011.jpg
12. To add your new texture to the MatCap, simply click on the little texture icon in the material modifiers and choose the texture from the popup.
A further note about twin sphere textures:
If you want to capture these exactly then the MatCap modifiers need setting for each sphere separately. For the left sphere, set Intensity A to 1, Intensity B to 0, Cavity Detection to 0 and Cavity transition to -1. For the right sphere, set Intensity A to 0, Intensity B to 1, Cavity Detection to 0 and Cavity transition to 1. You might also want to reduce Obj Shadow to 0 in the Render:Preview Shadows submenu.*
*Thanks to Svengali for pointing out how to adjust the sliders for twin spheres.
I hope you find this tutorial useful. The MatCap shown in the images - adapted from the default RedWax - is in the zip file.
The heart of a MatCap is its texture map - shown in the little icon at the bottom of the Material Modifiers. You'll see it has one or two spheres; these images provide the 'light map' which gives the material its lighting direction and color.
Sometimes you might want to change an existing MatCap rather than start from scratch with a new one. Here is one method that you can try.
1. First load the PolySphere ztool from the ZTools folder and divide until it is smooth. Make sure that it has UVs enabled. Create a new texture map of 1024 x 1024.
2. With your MatCap selected, draw the PolySphere on the canvas and enter Edit mode.
3. Make sure Perspective is OFF and then drop the model into Projection Master ('G').
MatCap001.jpg
4. Now go to the Layer palette and press 'Bake'. The B Blend slider should be set to 100.
MatCap002.jpg
5. Pick up from Projection Master, making sure only COLORS, DOUBLE-SIDED and FADE are selected. Most likely the PolySphere will now look rather dark and messy. To see the texture map properly press Render: Flat.
MatCap003.jpg
6. If you rotate the PolySphere you will see that the MatCap lighting and color has been transferred to the texture. There will be a seam which you can paint over if you want by dropping again into Projection Master and using the Clone and Smudge brushes.
MatCap004.jpg
7. Rotate the PolySphere until the light direction is as you want. Mark the position (press the M+ button in the Marker palette) so you can redraw the sphere if you need to.
MatCap007.jpg
8. With the PolySphere in Edit mode, make sure Preview Render is on and select the Fast Shader material. This will mean that the sphere will react to ZBrush's lights. Adjust the Ambient and Diffuse sliders so that the result is not too dark - I used 50 and 80.
MatCap008.jpg
9. Set up additional lights in the Light palette if you wish. For colored lights you will need to press Best Render (though you may not need to render with Shadows on).
MatCap009.jpg
10. When you are happy with the result use the MRGBZGrabber ztool to capture the texture.
MatCap010.jpg
11. Some MatCaps have two spheres in the texture map. You can add a second sphere to the new texture automatically using the MRGZGrabber. After setting up the second sphere, reselect the MRGBZGrabber and check that your new texture is selected in the Texture palette, then hold down the Ctrl key and grab the sphere.
MatCap011.jpg
12. To add your new texture to the MatCap, simply click on the little texture icon in the material modifiers and choose the texture from the popup.
A further note about twin sphere textures:
If you want to capture these exactly then the MatCap modifiers need setting for each sphere separately. For the left sphere, set Intensity A to 1, Intensity B to 0, Cavity Detection to 0 and Cavity transition to -1. For the right sphere, set Intensity A to 0, Intensity B to 1, Cavity Detection to 0 and Cavity transition to 1. You might also want to reduce Obj Shadow to 0 in the Render:Preview Shadows submenu.*
*Thanks to Svengali for pointing out how to adjust the sliders for twin spheres.
I hope you find this tutorial useful. The MatCap shown in the images - adapted from the default RedWax - is in the zip file.