Add Depth of field support for Grease Pencil #53947

New Issue

Antonio Vazquez · 2018-01-30T16:29:28+01:00

Antonio Vazquez commented

2018-01-30 16:29:28 +01:00

After review how work DOF in Eevee, I decide to use the same approach for Grease Pencil.

The first step is “accumulate” all GP drawing output to a new framebuffer and then apply a DOF filter similar to what you have in Eevee. This cumulative framebuffer would have all GP drawing stuff in one place.

The idea is to duplicate eevee_depth_of_field.c and create a new gpencil_depth_of_field.c. Basically both codes will be very similar, but I think is better to keep a separate copy because in the future they can diverge.

About shaders, Eevee define 3 shaders, but only uses 2:

extern char datatoc_effect_dof_vert_glsl[];
extern char datatoc_effect_dof_frag_glsl[];

Note: The geom shader is defined but is not used in the code.

These shaders will be duplicated in gpencil engine folder and customize to the requirements of GP. I know that Eevee and Gpencil DOF implementation would be almost identical, but I think is better to keep each engine with his own modules.

I was doing some tests last week, sending the current grease pencil framebuffer output through the DOF shader before sending to default framebbufer, and I got DOF effect for GP in the viewport, but I have two problems now:

The transparence is missing (@fclem told me about that) and any pixel with alpha = 0, get black.
The z-depth of the result is not right, but my idea is to use the z-depth of source texture and output in the resolve pass in the gl_FragDepth output.

(I have done all test in separated local branch)

After review how work DOF in Eevee, I decide to use the same approach for Grease Pencil. The first step is “accumulate” all GP drawing output to a new framebuffer and then apply a DOF filter similar to what you have in Eevee. This cumulative framebuffer would have all GP drawing stuff in one place. The idea is to duplicate **eevee_depth_of_field.c** and create a new **gpencil_depth_of_field.c**. Basically both codes will be very similar, but I think is better to keep a separate copy because in the future they can diverge. About shaders, Eevee define 3 shaders, but only uses 2: extern char datatoc_effect_dof_vert_glsl[]; extern char datatoc_effect_dof_frag_glsl[]; Note: The geom shader is defined but is not used in the code. These shaders will be duplicated in gpencil engine folder and customize to the requirements of GP. I know that Eevee and Gpencil DOF implementation would be almost identical, but I think is better to keep each engine with his own modules. I was doing some tests last week, sending the current grease pencil framebuffer output through the DOF shader before sending to default framebbufer, and I got DOF effect for GP in the viewport, but I have two problems now: 1) The transparence is missing (@fclem told me about that) and any pixel with alpha = 0, get black. 2) The z-depth of the result is not right, but my idea is to use the z-depth of source texture and output in the resolve pass in the gl_FragDepth output. (I have done all test in separated local branch)

Antonio Vazquez commented

2018-01-30 16:29:28 +01:00

Added subscribers: @fclem, @antoniov, @dfelinto, @JoshuaLeung, @pepe-school-land, @mendio