I am new to blender and I could use some help, i watched a lot of tutorials but I still can't paint an object, I click on the object but it doesn't add color. I enter on texture paint and all the stuff but when I try to add color it simply doesn't. What can i do?
You must create an image first. Click the new button at the bottom of the image editor to create a new image.
Before you can paint you will also have to assign that image to the object.
In BI select the image in the image editor while in edit mode, so that the UV map is displayed.
In Cycles add a texture node to the object's material, and set it to the image you want to paint on. The selected texture node defines which texture node to use:
Option 1 - If the brush default loaded under the Texture Paint Tool and Workspace tab is TexDraw, then the brush tries to paint with a texture. If no texture exists, it paints with a plain black square, which leaves no trace because the default color of the image texture is also black.
If that is the problem, you need to delete the texture. Then it doesn't use a texture to paint, but the plain circle of a normal brush. Then the brush strokes will show up fine. The needed section of the N panel tool section is shown outlined in red in the image.
Option 2 - the brush is 'bad', and you need to create a new brush. First delete it by clicking the x (outlined in blue in the image). By default, there are no other brushes, so the panel will change and show you the New Brush panel. Click on new. That will create a new brush, and this time it should behave with the default behavior - painting normally.
If you've got tablet pressure enabled for the brush strength, but you're using a mouse instead of a tablet, then nothing happens because the mouse has zero pressure, and so the brush has 0 strength. I was confused by this as flood fill was working fine, but the brush didn't seem to be doing anything.