GPv3: Convert radius to blender units #113770

Falk David · 2023-10-16T12:30:17+02:00

Falk David commented

2023-10-16 12:30:17 +02:00

Previously, Grease Pencil used a radius convention where
1 "px" = 0.001 units. This "px" was the brush size which would be
stored in the stroke thickness and then scaled by the point pressure
factor. Finally, the render engine would divide this thickness value by
2000 (we're going from a thickness to a radius, hence the factor of
two) to convert back into blender units.

Store the radius now directly in blender units. This makes it
consistent with how hair curves handle the radius.

Removes the scaling in the render engine.
Makes sure the grease pencil primitives use the correct radii
Changes the drawing tool to work with screen space radius
Draws the drawing tool cursor in screen space
Makes sure the scaling is done when converting from legacy
grease pencil objects
Makes sure the scaling is done when loading previous files

Consequences for the draw tool:

Since the tool has a radius input in pixels, it now works in screen space. This is a pretty big change to how it works by default before, so a new option will have to be added that allows the brush to be in "Scene" space. This is similar to how it works in sculpt mode. But this is a bigger change, so I would like to split that into a separate PR.

Previously, Grease Pencil used a radius convention where 1 "px" = 0.001 units. This "px" was the brush size which would be stored in the stroke thickness and then scaled by the point pressure factor. Finally, the render engine would divide this thickness value by 2000 (we're going from a thickness to a radius, hence the factor of two) to convert back into blender units. Store the radius now directly in blender units. This makes it consistent with how hair curves handle the radius. * Removes the scaling in the render engine. * Makes sure the grease pencil primitives use the correct radii * Changes the drawing tool to work with screen space radius * Draws the drawing tool cursor in screen space * Makes sure the scaling is done when converting from legacy grease pencil objects * Makes sure the scaling is done when loading previous files Consequences for the draw tool: * Since the tool has a radius input in pixels, it now works in screen space. This is a pretty big change to how it works by default before, so a new option will have to be added that allows the brush to be in "Scene" space. This is similar to how it works in sculpt mode. But this is a bigger change, so I would like to split that into a separate PR.

👍 1

Falk David added 1 commit 2023-10-16 12:30:32 +02:00

9931cf82b3 GPv3: Convert radius to blender units

Previously, Grease Pencil used a radius convention where
1 "px" = 0.001 units. This "px" was the brush size which would be
stored in the stroke thickness and then scaled by the point pressure
factor. Finally, the render engine would divide this thickness value by
2000 (we're going from a thickness to a radius, hence the factor of
two) to convert back into blender units.

Store the radius now directly in blender units. This makes it
consistent with how hair curves handle the radius.

* Removes the scaling in the render engine.
* Makes sure the grease pencil primitives use the correct radii
* Changes the drawing tool to work with screen space radius
* Draws the drawing tool cursor in screen space
* Makes sure the scaling is done when converting from legacy
grease pencil objects
* Makes sure the scaling is done when loading previous files

Falk David added 1 commit 2023-10-16 12:31:07 +02:00

a266b6fe7a Fix power of two grain size

Falk David added 1 commit 2023-10-16 12:48:21 +02:00

28bf7b03a9 Use same minimum radius as before

Falk David requested review from Clément Foucault 2023-10-16 12:49:48 +02:00

Falk David requested review from Bastien Montagne 2023-10-16 12:49:56 +02:00

Dalai Felinto commented

2023-10-16 12:59:53 +02:00

It seems to be working well on my simple tests with geometry nodes.

Bastien Montagne requested changes 2023-10-16 16:06:04 +02:00

Bastien Montagne left a comment

Besides the fact that this versioning needs a blendfile subversion bump, LGTM from quick look over.

source/blender/blenloader/intern/versioning_400.cc Outdated

						
				@ -1691,5 +1715,8 @@ void blo_do_versions_400(FileData *fd, Library * /*lib*/, Main *bmain)

				   */

				  {

				    /* Keep this block, even when empty. */

				    LISTBASE_FOREACH (GreasePencil *, grease_pencil, &bmain->grease_pencils) {

Bastien Montagne commented

2023-10-16 16:04:09 +02:00

You need to raise the blendfile subversion for this, otherwise you risk re-applying that conversion more than once, which is not a desired behavior I'd assume.

filedescriptor marked this conversation as resolved