To avoid anti-aliasing artifacts on GPencil strokes that have a size smaller than 1 the thickness
is clamped and the opacity reduced. This was done in vertex shader but this had the side effect
of causing strokes that go from large to small to fade across their lengths.
**Solution**
The opacity modulation has now been moved to the fragment shader as advised by Clément Foucault.
The strokeThickness that was passed to the shader was clamped to prevent it from being too small so an additional
unclamped thickness has been passed to the fragment to calculate the opacity modulation. Alternatively I could have chosen
strokeThickness and clampedThickness but I decided against renaming the variables in the current code.
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D10438
The grease pencil merge depth shader is designed to only work correctly
in octographic mode. The uv coordinates used `noperspective` attribute.
Somehow this doesn't lead to render artifacts on most platforms and was
only detected on OSX + AMD cards.
This fix would calculate the uv coordinate inside the fragment shader
and isn't passed along from the vertex shader.
Thanks to Sebastián Barschkis for providing the hardware and time and
Clément Foucault for helping out with the final fix.
This new feature allows to use the strokes as an eraser of any stroke below. This is very handy to open holes in filled areas.
After running some tests, we have decided to keep the additive effect of the holdout color. To get clean holdout areas, just move the color to black to remove any additive effect. To have additive effect can be used in situations like tint slightly a transparent window with blue to simulate the glass.
See T79878 for more details
Differential Revision: https://developer.blender.org/D8932
The gpSceneDepthTexture is using a dummy 1px texture which was generating
wrong values for uvs when sampling gpMaskTexture.
Use the max size of both since any of the 2 can use dummy texture.
It seems like OSX drivers are using standard attributes for passing
gl_VertexID and gl_InstanceID to the vertex shader, and count them in the
limit of MAX_VERTEX_ATTRIBS.
This patch make sure to never use more than 13 attributes by packing some
attributes together.
This commit is a full refactor of the grease pencil modules including Draw Engine, Modifiers, VFX, depsgraph update, improvements in operators and conversion of Sculpt and Weight paint tools to real brushes.
Also, a huge code cleanup has been done at all levels.
Thanks to @fclem for his work and yo @pepeland and @mendio for the testing and help in the development.
Differential Revision: https://developer.blender.org/D6293
Now the fade layer uses the same logic used to fade objects and also is available in all modes.
Reviewers: mendio, pepeland
Reviewed By: mendio, pepeland
Differential Revision: https://developer.blender.org/D5707
Before, it was only possible to fade the active object. The new option allows to fade all non gpencil selected object. This is a common request by artists.
{F7719513}
Reviewers: mendio, pepeland
Reviewed By: mendio
Differential Revision: https://developer.blender.org/D5704
Migrate old legacy code to the draw mamager/object mode. The old legacy
version did not work with wireframe. By migrating the code
to modern draw manager code we have mode control on the drawing process.
Still background images do not work with OIT, the cause seems to be that the transparent pixels are treated as background pixels.
Also There are some artifacts when working with Holdouts and DoF, this
is because the draw engines do not pass the correct alpha values.
Reviewers: fclem, brecht
Differential Revision: https://developer.blender.org/D4638
Now texture storage of images is defined by the alpha mode of the image. The
downside of this is that there can be artifacts near alpha edges where pixels
with zero alpha bleed in. It also adds more code complexity since image textures
are no longer all stored the same way.
This changes allows us to keep using sRGB texture formats, which have edge
darkening when stored with premultiplied alpha. Game engines seems to generally
do the same thing, and we want to be compatible with them.
