The following table lists common problems and possible solution related to painting:
| Problem/Error Message | Possible Solution |
|---|---|
Paint strokes appear uneven or with a stuttered appearance. |
The Stamp Spacing property is set too high. Decrease the Stamp Spacing value and try again. Check that the Randomize property is turned off. |
Paint cannot be applied to some regions of the model. The unpaintable regions appear as streaks or paint artifacts. |
Artifacts can appear when painting on a model whenever the UVs overlap, are positioned too close to each other, or are positioned too close to the UV tile border. UVs should be positioned so an empty region (4 to 6 pixels in width) exists along the outside the perimeter of each UV shell to account for the necessary edge bleed that automatically occurs when painting. View the UVs for the model by clicking the UV View. Dolly and track the camera within the UV View to determine if any of the above described situations exist. If so, you must re-edit the UVs in another 3D modeling application equipped with UV editing tools (Maya, 3ds Max, and so on) to correct the problem and then import the model again. Keep in mind that if you shift the UV positions when you re-edit them, any previous paint work will not be registered. For more information, see Prepare a model for painting. |
UVs didn’t appear in the UV View initially but I was able to paint on the model. |
Mudbox doesn’t apply paint to a model unless there are UVs present, so UVs must exist on a lower subdivision level. UVs only appear in the UV View if they exist for the current subdivision level that’s currently displayed. As soon as you create a paint layer on a subdivision level without UVs, Mudbox automatically creates them for all levels in-between the base level and your current level. In the 3D View, press the Page Down key repeatedly until the UVs appear. If you want to recreate UVs on a higher subdivision level, press Page Up in the 3D View until you’re at the desired subdivision level, then select Mesh > Recreate Level UVs. |
Air brush paint strokes appear with uneven blending when the paint layer color channel is set to 8 bits. |
Artifacts (concentric rings in the brush stamp) can appear in an air brush paint stroke with particular color hues (cyan, gray scale) whenever the Brush Size is relatively large in relation to the layer resolution. This occurs due to the limited bit depth in the specified color channel. If this occurs, specify a paint layer that is 16 bits in depth (for example, OpenEXR 16 bit Floating Point RGBA). |
Cannot erase paint from the model. |
Ensure you have the correct paint layer selected in the Layers window prior to using the Paint Erase tool. Paint Erase erases paint only on the selected layer. Ensure the selected paint layer is not locked. A lock icon appears to the left of the layer name if the paint layer is locked. |
| Two paint cursors appear on the surface of the model when painting. | The Mirror property for the tool is turned on. If you don’t want to apply paint in a symmetrical fashion, turn off the Mirror property. For more information, see Paint properties. |
Stamp or stencil images appear tinted when applied to a model as a paint layer. |
Ensure the Color property of the paint brush is set to white. This ensures that the original color of the image is maintained. For more information, see Change the paint color. |
A semi-transparent image appears in the 3D View. |
You may have a stencil image selected for the active camera view and want to turn it off. In the Stencil tray, click the Off icon. |
Painting on a model using the Projection feature with the Mirror property turned on produces unexpected results. |
Remember that when the Mirror property is on and you apply paint through a stencil, different areas of the stencil image are applied to opposite sides of the model. As a result, the paint will most likely not appear symmetrical. Don’t use the Mirror property in these situations. For more information, see Paint properties. |
An additional file appears in the files directory that stores the paint work associated with my .mud file. Its name contains the text Background. What is this file used for? |
An image file containing the text Background in its filename gets saved to the files image directory when a model is saved after painting. This small image records the model's default material color so that it appears through any unpainted (transparent) regions of the paint layers. Otherwise, unpainted (transparent) regions would appear incorrect when rendered. If a model contains multiple UV tiles, there will be one background image file created for each UV tile per layer channel. |
