Fill Brush with Radial Gradient not working with Project Paint

Question

I have modeled a leopard frog with the mirror modifier and unwrapped it, and am attempting to paint the diffuse texture in the 3D viewport. When using the draw brush, painting works fine. When using the fill brush without a gradient, it works as expected.

My problem occurs when I try to use the radial gradient option on the fill brush to paint the spots of the frog. The results are mostly crap. For example, I'll paint the top of the body, and it paints a spot on the bottom as well. Or I'll paint on the side of the body and the spot shows up on the belly instead. Sometimes, the brush won't even work and I have to fiddle with re-unwrapping and making a new image to paint on to get it to work again. I feel confident the problem is not my UV map; I have islands for the legs, body, inner mouth, hands, etc. No vertices are overlapping in the UV editor. When I texture paint from the UV window, I get no unexpected results. For some reason the fill brush just completely craps out on me when I use a radial gradient in the viewport.

I should add that I've tried toggling Occlude, Cull and Normal options in the toolbar to no effect.

I'm really at a loss for what to do here. Is there a better way to paint the spots? Is radial gradient fill just plain broken?

Answer 1

I think that actually we need to think in regards to how to arrive at the radial gradient dots on the target image. The gradient fill brush is going to fill the whole image, and works from clicking somewhere in the image and pulling away from center to create a radial gradient fill.

My preferred way to do this is to use a Blend texture set to radial, and in the brush settings I set it to stroke type 'Anchored' and change 'Tiled' mapping to 'View Plane'. Define your gradient there in the place in the texture panel marked 'color' and then set your stops to the colors of your choice. If you already have a gradient worked out, hover over it and press ctrl-C to copy it, and hover over this color ramp and press ctrl-V to paste it in. Click in the image area on your mesh, and the dragging away you should get a preview of the colors and size before release.