Q100709: Resolving Painting issues in Mari

You can use Mari’s Mask Preview Enabled setting to find out if your object is being masked by some Mari effect. In order to use the Mask Preview Enabled option, navigate to your painting palette. Under Projection Settings > Masking, ensure that Mask Preview Enabled is ticked. If at this stage any or all of your Object turns pink, this means that there is something masking your object. Either part or all of your Object is locked, or you may have a viewport painting Mask enabled.

Image 1: In this image you can see that the Object has been partially masked out.

Check what your paint blending Mode and Painting Opacity are set to. These settings are located in the Painting palette, under Projection Settings > Painting. The paint blending modes allow you to change the way that your paint data is applied to your object, but in some cases this will result in it appearing like your paint is invisible or has disappeared. You can read more about all the paint Blending Modes available in Mari here:
Mari Docs: Paint Blending Modes

If in doubt, and you are unable to see your paint, change the paint blending mode to Normal, which is the default setting. 

Image 2: The default painting Mode and Opacity.

Likewise, if the Painting Opacity option is set to 0, you will not be able to see your paint data. Try setting this value to 1.

Mari allows you to restrict where paint is applied to only your currently selected Faces or Patches. This is off by default, but if you happened to have left it on and you don't have anything selected, you won't be able to paint at all.

In your Painting palette, select Projection Settings > Projection > Project On. If you find this set to SelectedOnly, change it to All to deactivate this restriction.

Image 3: The Projection Settings, with the Project On option highlighted.

The Viewport Paint Masks will mask your Object if they are enabled, which may prevent you from painting. You can find your Viewport Paint Masks in your Painting palette, under Projection Settings. You can quickly check if any Masks are enabled by looking at the toggle to the right of Mask. If the Mask is enabled, the toggle will be slid to the right, and there will be a green dot next to the button.

Image 4: The Projection Settings, with the Viewport Paint Masks highlighted. Here you can see that the Edge Mask is enabled, and all other Masks are currently disabled.

It may be that you can't paint because your Object, Selection Groups, or Patches are locked. Just like with Viewport Paint Masks, you can check whether something is locked by enabling Mask Preview Enabled. If an area of your Object turns pink, then it's locked or masked out.

Navigate to the menu bar at the top of the Mari UI, and select Selection > Unlock Entire Object. If your Object loses its pink colour, this means it was locked but you've now unlocked it, and you should now be able to paint.

Image 5: The Selection Menu, with the Lock/Unlock options highlighted.

In Mari, you can only paint on the Paint Buffer. However, as you can transform the Paint Buffer, it is possible that you have moved the Paint Buffer away from the area where you are trying to paint. In that case, you can reset your Paint Buffer so that it fills the whole Canvas by selecting the Transform Paint Buffer tool and pressing the Reset Buffer button found on the Tool Properties toolbar.

Image 6: The Transform Paint Buffer tool on the Tools Toolbar.

Image 7: The Reset Buffer option. This option will only appear when the Transform Paint Buffer tool is active.

Any painting tool in Mari can be modified to suit your needs. In some cases, you may have modified your painting tool so that its Opacity and Flow have been set to zero. These settings will make it seem like nothing is happening when you paint. You can find and reset these settings in the Tool Properties toolbar with your painting tool selected. 

Image 8: Some of the painting tools found in the Tools Toolbar.

Image 9: The Tool Properties Toolbar when the paint brush is selected. The Opacity and Flow values are highlighted.

The Marquee Select tool allows you to select areas in your Canvas by dragging a free-form selection window. When you have something selected with the Marquee Select tool, you will not be able to paint anything outside the selected area. In some cases, this selection can still be active without you realising, meaning that it will seem like you cannot paint on your Object.

Image 10: The Marquee Select tool.

To reset the Marquee Select tool, select the tool on your Tools Toolbar and select the clear selection button on the Tool Properties Toolbar. This will deselect any marquee selection you may have made.

Image 11: The clear selection button.

In Mari, it is important to keep in mind that you can be painting on one node and viewing another, which could mean you're not seeing what you’re painting. To explain this, it is firstly important to understand the concept of the Current Paint Target.

The Current Paint Target is the Paint node that you will be baking Paint data to. The Current Paint Target is always a Paint node, and you can tell which Paint node is your Current Paint Target because the Paint node's label will be orange instead of red. Paint data will be baked to your Current Paint Target, even if you aren't viewing that node or if you have another non-Paint node selected. 

Image 12: In this image, there are two Paint nodes, named CoolPaint 1 and 2, one Merge node and the Viewer node. The CoolPaint1 node is the Current Paint Target, shown by its orange label. The Merge node is selected, shown by its yellow highlight.

No matter which node you have selected, if you paint anything in the Canvas, that data will be stored in the Current Paint Target. However, sometimes no paint seems to appear in your Canvas. In that case, the first thing to check is what Node you are viewing. 

The Current Paint Target is independent from what node you’re viewing, which can lead to confusion. In Image 13, CoolPaint1 is the Current Paint Target but CoolPaint2 is being viewed. This means we won’t see any changes in the Canvas if we paint a brushstroke. This can lead us to believe that we can’t paint, but in actuality we are painting on a Paint node that we’re not looking at. If you find that you cannot see your paint, ensure that you are viewing the Current Paint Target.

Image 13: In this image we cannot see any paint strokes we make, as we are not viewing the Current Paint Target.

When working with Layers in Mari, in order to be able to paint you need to have a paintable Layer selected. This can be a paint layer or a Layer Mask. The currently active paint target is marked by an orange icon. For a normal paint layer, this will be an orange painting palette icon; for a Layer Mask, this will be an orange square icon with a circle in the middle. 

Image 14: The Layers palette, showing two Layers. The Diffuse_Colour layer is a paint layer, as shown by the painting palette icon. The Mask layer has a Layer Mask, shown by the additional square icon. The current paint target is the Diffuse_Colour layer, as the palette icon is orange.

The next thing to check once you have confirmed you’ve got a paintable Layer selected is to check if that Layer is locked. In the Layers palette, you will see a grey padlock to the far right of every Layer. If the padlock on your selected Layer is set to closed, you will not be able to paint on the Layer. Set the padlock to unlocked by clicking the padlock icon in order to be able to paint.

Mari offers several ways to view your Layers, and you can explore them through the Project Controls toolbar. If you have a Layer selected, but you cannot see the paint, you may want to use the Current Layer view button, which will display only the Layer you have selected. If you have one Layer selected, but another Layer is the Current Paint Target, and you would like to see what you’re painting on the Current Paint Target, you may want to use the Current Paint Target view button.

Image 15: The Project Controls toolbar displaying all the options.

If you are using Masks or the Mask Stack with Layers, you may find that you cannot see your paint because you have a Mask occluding your paint. Using the Current Layer view button can help you isolate Layers and determine whether a Mask is preventing you from seeing your paint.

Depending on your hardware, if you find that you can paint on the Paint Buffer, but then encounter issues baking this paint onto your Object, you may need to adjust the resolution of your Paint Buffer. This may particularly be the case when you also encounter some performance issues when painting on your Buffer.

In the Painting palette, select Painter > Paint Buffer > Paint Buffer > Buffer Size. If Buffer Size is currently set to a high resolution like 8192 x 8192, choose a lower setting and check whether that allows you to bake paint.

Image 16: The different options for your Buffer Size.

If you’re painting a Mask but you’re unable to see your brushes’ soft edge or Opacity, then the Paint node you’re using contains transparency. In other words, your Paint node’s Alpha value is not set to 1 (1 means completely opaque, while 0 means completely transparent). 

Mari does not support transparency on the Merge node’s Mask input. An Alpha of 0 in the Paint node will be perceived by the Mask input as black, while values between 0 and 1 are semi-transparent areas which will be perceived by the Mask as white instead. Painting using a brush with soft edges or low opacity on transparent areas of a Paint node leads to these semi-transparent areas. The result is that all brush strokes are fully opaque.

Image 17: An example of a node setup where a transparent Paint node was used as a mask. As you can see in the Canvas, the brush strokes have a hard edge.

To avoid this issue in the future, ensure that any Paint node you intend to use as a Mask has an Alpha value of 1. This results in a fully opaque Paint node from which you can start to paint your Mask. 

In Image 18, the Color setting in the Add Paint Node dialog shows that we are creating a Paint node with transparency, indicated by half the thumbnail having a grey checkerboard. By clicking the thumbnail we open the Select Color dialog. Here, the Alpha channel shows a value of 0.0, meaning that the node will be transparent. This should be changed to 1.0 if we intend to use this Paint node on a Mask input.

Image 18: A Paint node being created with transparency.

It may be that you’ve been painting on a Paint node to use as a Mask, but now you’ve found that it contains transparent areas (as indicated by a grey checkerboard if you view it). In this case, it’s possible to remove the transparency while saving the work you’ve already done. Simply Merge your Paint node with a Color node that is black with an Alpha of 1, and plug the result into the relevant Mask input, as pictured below:

Image 19: The workaround node setup for when you have mistakenly used a transparent paint node and don’t want to start from scratch. The soft edges of the brush are now visible again.

Once the Mask input is not receiving transparent values, your brush’s soft edges and Opacity will be restored.

If the paint is projected across your Object in areas you’re not painting in, and/or the paint is warped, this may be due to overlapping UVs. For best results in Mari, it is recommended that your Objects have unwrapped UV shells organised so that they do not overlap. Overlapping UVs can cause the paint to project in unwanted ways.

Image 20: In this image you can see the UVs of the cube on the right before baking. As these UVs are overlapping, the paint on the Ortho view on the left is distorted on the UV view.

Image 21: After baking the paint, the paint is projected in unexpected ways across the Object. You can see where the UVs have overlapped and have created harsh lines across the paint.

This cannot be resolved within Mari, however. To fix this issue you must rearrange your UV shells using a UV editor in a modelling application.

If you are seeing visual issues when baking your paint, please check whether your GPU drivers are up to date. Mari is very reliant on your GPU for performance and fidelity, and so it is very important that you ensure your GPU drivers are regularly updated. You can learn more about how Mari uses your hardware components in the following article:

Q100078: Mari's usage of hardware components