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 strokes appear shaky and unsmooth in appearance. |
It can be difficult to produce long smooth paint strokes without introducing shakiness from your hand. Turn on Steady Stroke to improve smoothness. See Produce smooth tool strokes. |
| When painting very large texture datasets, Mudbox becomes less responsive. |
The Gigatexel Engine operates to let you paint enormous texture datasets. However, your system performance can degrade if the textures exceed the amount of RAM available on your system. You can get significant speed increases when working with particularly large textures by investing in more CPU memory and a solid-state hard drive (SSD). See also Graphics memory optimization. |
| Paint cannot be applied to some regions of the model. The regions appear as streaks or paint artifacts. |
Artifacts can appear when painting on a model if the UVs overlap, are positioned too close to each other, or are positioned too close to the UV tile border. View the UVs for the model by clicking the UV View. Dolly and track in 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 or import only the UVs using File > Import UVs. If you shift the UV positions when you re-edit them, any previous paint work will not be registered, but you can transfer paint layers. See Transfer paint layers. See also Prepare a model for painting. |
| Paint cannot be applied to some faces on a model. |
Subdivide the model one or two times and try painting again. Increase the Brush Sample Area value in the Paint preferences. |
| Artifacts appear on the mesh as I try to paint, or paint always appears black. |
This can be caused by an issue with some graphics card drivers. If you experience these display issues, set the environment variable MUDBOX_PAINT_CONTEXT_FLUSH to 1. See also MUDBOX_PAINT_CONTEXT_FLUSH. |
| Paint applied to one model appears on other models in the 3D View. |
Models imported to Mudbox are assigned the Mudbox Material by default. When you paint on a model, the paint layer creates a texture map behind the scenes that is applied to the associated material property (diffuse, bump, and so on). If models share the same material, they also share any paint that is applied to any of the models unless the UVs for each model are laid out in separate tile spaces. To avoid this, assign separate materials to the various models so any paint you apply is unique to each model. If you want the models to share the same material, lay out the UVs so they do not overlap or lay them out in different tile spaces before importing to Mudbox. For more information, see UVs overview and Paint across multiple UV tiles. |
| UVs did not appear in the UV View initially but I was able to paint on the model. |
Mudbox does not apply paint to a model unless there are UVs present. In this case, UVs are likely present on a lower subdivision level. UVs only appear in the UV View if they exist for the current subdivision level. When you create a paint layer on a subdivision level without UVs, Mudbox automatically creates UVs 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 the desired subdivision level is displayed, then select Mesh > Recreate Level UVs. |
| When viewing the 2D painted image in the UV View, the painted regions appear white. |
Check the current subdivision level on the model. At high subdivision levels, the UV mesh will appear as a very dense white mesh in the UV View. Press the Page Down key to display a lower subdivision level to reduce the density of the UV mesh and reveal the painted image. |
| Airbrush 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 Airbrush paint stroke with particular color hues (cyan, gray scale) if the brush Size is relatively large compared 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 do not want to apply paint in a symmetrical fashion, turn off the Mirror property. For more information, see 3D 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 maintains the original color of the image. See Change the paint color. |
| A semi-transparent image appears in the 3D View. |
A stencil image or image plane may still be active for the current camera view. Turn off the stencil or image plane in the respective tray or Properties window. |
| An additional Background file appears in the files directory that stores the paint work associated with my .mud file. What is this file used for? |
An image file containing the text Background in its filename is 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, one background image file is created for each UV tile per layer channel. |
| Model appears with multicolored square-shaped tiles on its surface in the 3D View. |
Models with multiple UV tiles are automatically displayed with their textures turned off to reduce graphics memory usage and optimize interactive performance. The multi-colored tiles indicate the unloaded state for texture tiles. You can manually turn on or off the display of textures for any UV tile using the arrow keys. See UVs overview and Hide and show texture tiles on a model. |
| The following message appears when painting on a model: To paint this area, you must first load the UV tile. Hold the cursor over the area and press up arrow to load or unload the tile. |
This message indicates that the area of the model you are attempting to paint is associated with a UV tile that is currently unloaded. Display the UV tile before painting on it. See Hide and show texture tiles on a model. |
| When painting high resolution paint layers on a model with multiple UV tiles, a noticeable pause occurs between the stroke and paint appearing on the model. |
To improve performance under these circumstances, disable the Undo feature for painting by selecting (Windows and Linux)Windows > Preferences > Paint > Disable Paint Undo or (Mac OS X)Mudbox > Preferences > Paint Disable Paint Undo. |
| Cannot paint on a region of the model. The following message appears: Only separated tiles are supported |
One or more UV shells on the model are positioned across a UV tile border. UV shells must be completely contained within a UV tile. For more information, see Prepare a model for painting. For more information on viewing the model UVs see, View painted images with UVs. |
| The following message appears when displaying all UV tiles on a paint layer: Displaying many texture tiles may consume available video memory and degrade performance. Continue? (Yes, No) |
This message is a reminder that displaying all texture tiles on the model at once may consume all of the video memory depending on the number of tiles and the resolution of the textures on each. When this occurs, the system performance may be slower than expected. |
| Painted regions on multi-tile model do not appear in the UV View. |
When multiple UV tiles exist on a model, only the paint associated with the currently loaded tile(s) appears in the UV View. To load and unload UV Tiles, see Hide and show texture tiles on a model. |
| Switching my graphics display to 8 or 16 bit color results in many of the paint tools not working. |
The paint tools in Mudbox are designed to work in 24 bit color (True color). Your graphics display must be set to this mode for the paint tools to work correctly. |
| The paint layer appears transparent except for the regions that were painted. |
This is correct. A paint layer is fully transparent until you apply paint to it. The color that appears behind the paint is the diffuse color of the assigned material or the paint layer below it. |
| The Dry Brush applies paint to both the raised and recessed regions of the sculpted surface. |
Reduce the Size property for the Dry Brush. The Dry Brush works by calculating the average height of vertices within the brush ring, so a brush Size that is too large can impede the effect. See Paint using a dry brush technique. |
| The Re-import from PSD feature doesn’t work as expected and fails to project the texture back onto the object. I am running an un-certified graphics card. |
Setting the following environment variable on computers running Mudbox using older graphics cards may allow the feature to work correctly: MUDBOX_OLD_PAINTFLOOD = 1. |
