Community Bonding period - Final week (31 May to 6 June)
Meeting with Daniel Bystedt to discuss and finalize implementation details for ideas in the proposal. Main points of discussion :
The original idea of packing UVs to correct/desired UDIM was limited to only work when the user had a UDIM texture present in the UV editor. It was agreed that the user should never need a UDIM sequence to dictate how the UV will pack or unwrap. Task description/design was updated accordingly.
It was agreed that making the increment snapping value (default : 0.0625 units) user-editable in the UV editor didn’t have many practical benefits. Use cases for this are limited and would create problems in UV workflows. Further discussion with mentor is required for this.
Adding an option to the new pack islands to area operator, where the user can decide if they want islands to be scaled when packing UVs.
Revised working order for GSoC tasks is listed below :
Pack UV islands to correct/specified UDIM (T78397) :
Make increment snapping value user-editable in the UV editor (No task created on d.b.o. Original idea can be found in proposal)
Started and completed a rough implementation for the first task - pack islands to correct/specified UDIM.
Experimented with the code in overlay_grid.c, mostly changing the UDIM grid density.
Figured out how to toggle/hide operator properties in the UI
Continued study of the box packing algorithm used in Boxpack_2d.c
Plans for next week - 7 June to 13 June
Official coding period for GSoC starts this week
Complete implementation of task - Pack islands to correct/desired UDIM
Start working on the implementation for next task - Pack islands to box area. Look for a new box packing algorithm that can work with different areas, similar to BLI_box_pack_2d_fixedarea() .
Create a new design task on phabricator for GSoC related tasks. Similar to - (T77408)
Discuss with mentor about the usability of idea - Make increment snapping value user-editable in the UV editor
Completed implementation of first task (Pack islands to correct/specified UDIM) - commit link (pending review)
2 new options added to the pack islands operator
Closest UDIM will pack the selected islands to the UDIM they were originally placed on. If the selected islands were not placed on any UDIM tile they will be packed to the nearest UDIM tile
Specified UDIM will let the user define the UDIM they want to pack the selected islands to
Implementation works with UDIM grid and UDIM textures
Submitted a patch for a minor fix (D11582). This is implemented in the soc-2021-uv-editor-improvements branch
Started working on the second task - Pack islands to box area
I couldn’t work this weekend since I got vaccinated on Saturday (12 June) and was down with fever.
Plans for next week - 14 June to 20 June
Continue working on the second task - pack islands to box area
Test the implementation for the first task
Refactor the code and cleanup - create smaller functions to simplify logic
Investigate bugs or deviations from intended behavior
Thanks for your contribution!
I personally have several proposals:
Alignment tools: can be used to manually align and arrange uv islands, works just like 2D graphic softwares adobe illustrator or inkscape etc.
Average islands scale according to the active island: the way Average islands scale command currently works is to scale every selected island to match a ratio. By adding a option, to make it possible to set the active island to be the base or reference, keeping it untouched and scale others.
Export UV Layout with real world units: by now, blender can exports vector file formats as SVG and EPS, consider supporting pdf format and keep it’s size and unit the same as the meshs’ size and unit. A very good reference implent is a addon comes with blender called “Export Paper Model”.
Average islands scale according to the active island : The idea does seem like a nice addition to the existing average islands scale operator. I’ve added it to a separate list of secondary tasks and will look into it once I’ve completed my primary deliverables.
Export UV Layout with real world units : This actually falls out of scope for the summer of code project, since I’m primarily working with the UV editor.
Completed a basic implementation of the second task - Pack islands to box area (T78398)
New operator added to the UV editor - Pack islands to area
Testing the operator with 15 monkeys
A few issues with the new operator that need to be resolved
When scale islands is disabled, islands that do not fit within the packing area are transformed to the bottom left corner where they will overlap with other islands
Zooming in/out in the UV editor changes the packing area when the operator is used again by modifying one it’s properties
Plans for next week - 21 June to 27 June
Fix issues with the new operator listed above
Start and complete implementation for next task - Dynamic grid (T78389)
Schedule a short meeting with mentor to resolve a few design issues
Implemented Dynamic Grid as described in design task - T78389
New option in the UI panel
If the value entered in the Grid size field is N then the 0-1 UV space is divided into a NxN grid
Worked on replicating Grid behavior of the 3D viewport in the UV/Image Editor. Specifically adding more/less divisions to the grid when zooming in/out in the viewport.
Investigated the code used for drawing the grid overlay in the 3D viewport and UV/Image editor. Also studied relevant shaders - grid_vert.glsl and grid_frag.glsl
Implemented a rough version of the grid in the UV editor. Currently working on a patch for the same.
Added a property for displaying packing area coordinates in the pack islands to area operator
Minor cleanup and fix
Plans for next week - 28 June to 4 July
Work on clean-up, refactoring and bug fixing.
Complete the implementation for improved UV editor grid. A few design decisions need to be finalized with mentor
Look into the implementation for the next task - Grid snapping in the UV editor
Implemented a new subdividing grid in the UV Editor, similar to the 3D viewport :
Changed the behavior of increment snapping in the UV editor - 86023928ba79
As observed in the 3D viewport, increment snapping value changes based on the grid resolution. Each increment is equal to the distance between 2 grid points at a given zoom level.
Since the grid in UV editor now also behaves similar to the 3D viewport (subdivide on zooming in), the behavior for increment snapping in UV editor has been updated to work the same way.
This behavior also works with dynamic grid that was implemented last week.
Plans for next week - 5 July to 11 July
Update the design task T88990 and add details about the progress made so far.
Start working on the 4th task - Grid snapping in UV editor and hopefully complete it this week.
Initial plan was to add Grid snapping as a new snapping option, but since it only affects UVs during translation/moving, I decided to add it as a toggle instead.
This replicates the same option found in the 3D viewport and makes it more consistent across both editors
Works with the new subdividing grid, and dynamic grid as well
Did some general testing on the soc branch, to identify any bugs or issues that need to be addressed. Apart from some minor issues I didn’t notice anything serious.
Worked on a small improvement for pack islands to area operator
Island rotation when scale islands is disabled is inefficient in the current implementation.
Tried implementing a better solution for this, but has some issues that need to be resolved
Due to some unfortunate events, this week wasn’t much productive.
Plans for next week - 12 July to 18 July
First evaluation this week
Complete the small improvement for pack islands to area operator
Work on clean up and refactoring for the work done so far
Short meeting with mentor to discuss further tasks
Completed an implementation of UV Offset operator (T78405)
Selected UVs can be moved with an offset that is specified by 2 different sets of key maps
CTRL + ARROW KEYS - Offset is the distance between 2 UDIMs
ALT + ARROW KEYS - Offset is one dynamic grid unit
A few bugs need to be addressed when using this operator with UV sync selection
Started working on T76545 - Edge selection support for UV editing
Mostly spent time studying the code in uvedit_select.c
Work for this task will be uploaded as a separate patch since I want to get an early review on this
Started working on some minor changes in the selection code. Mostly adding use cases for new selection flag (MLOOPUV_EDGESEL)
Current solution I’m working on ensures that each MLoopUV is associated with a UV vertex and edge. Each UV edge will be formed by 2 consecutive loops in the same face and setting the edge selection flag for the first loop ensures that the edge for that loop is marked as selected.
This solution ensures that if 2 continuous UV vertices are selected and the edge selection flag is not set for their corresponding UV edge, then that edge will not be marked as selected in the UV editor. This overcomes the current limitation which marks an UV edge as selected by only checking if the 2 associated UV vertices are selected.
I’m still working on how to draw selected UV edges and flushing selection between vertices and edges. For the drawing part I suspect most of the work to be done in overlay_edit_uv.c and draw_cache_extract_mesh_extractors.c
Plans for next week - 19 July to 25 July
Continue working on the task - Edge selection support for UV editor.
Spend sometime to work on cleanup for the soc branch
Worked on T76545 - Edge selection support for UV editing. I decided to not commit the work done for this to the soc branch and created a separate patch instead.
Work in progress patch for this task : ⚙ D12028 UV: Edge selection support
Reverted the changes made in the commit ( rB9fa29fe7652a), which removed the UV edge selection flag (MLOOPUV_EDGESEL)
Refactored the existing element selection functions for vertex, edge and face selection to use the UV edge selection flag.
Added new functions for selecting UV vertices and edges that share the same location (on mesh or in UV space)
Sticky selection modes now respect the current UV selection modes with a few exceptions (design tradeoffs). This means, edge selection mode will only allow edges to be selected and similar case for other UV selection modes as well. This fixes the previous behavior where edge selection+sticky vertex would allow edges and a few stray vertices to be selected as well.
Made changes to the UV select all operator to use the edge selection flag. As a temporary fix, invert all for face and island selection modes, both use the logic used for vertex selection mode as fallback.
Added a penalty factor to uv_find_nearest_edge() similar to the one used in uv_find_nearest_vert(). Previously with sticky selection disabled, if 2 UV edges shared the same position, then trying to select any of the 2 edges would always select a particular (fixed) edge instead.
Presently, there’s no way to visually differentiate between a selected UV edge and a state where only 2 consecutive UV vertices are selected (edge between them isn’t selected).
I tried experimenting with the shaders but finally decided to work on this later since I was unable to come up with a temporary fix for this.
Due to some time constraints, I couldn’t work on code cleanup for the soc branch this week.
Plans for next week - 26 July to 1 August
Work on refactoring the existing UV selection operators (box, lasso, circle)
Work on flushing selections between vertices and edges.
Spend sometime to work on cleanup for the soc branch (hopefully)
Edge and Face selection in UV editor should now function similar to how they work in the 3D viewport. (with UV sync selection disabled)
New UV face selection behavior is demonstrated below (for comparison with current master behavior, refer T78757):
New UV edge selection behavior :
Added functions for flushing UV selections between verts and edges (mode independent flushing). Flushing based on selection modes is currently not implemented since switching between UV selection modes is not done using an operator.
Fixed a bug introduced in last week’s implementation
With edge select + sticky location mode, trying to deselect an edge would deselect the neighboring edges as well.
This was actually caused by an invalid selection state where the neighboring edges were marked as selected but one of their vertices was not selected.
Plans for next week - 2 August to 8 August
Code cleanup
Provide builds of the soc branch and D12028, so that users can test/play with implemented features, provide feedback and report any bugs that need to be fixed
If time permits, work on edge selection support for edge loop and edge ring select operators
Final week of GSoC coding period. This week I mostly worked on clean up and testing implemented features on both soc branches.
I had some college work that kept me busy for a few days so I couldn’t work on adding edge selection support for UV select path and Rip tool.
Updated D12028 to reflect all the changes made on the soc-2021-uv-edge-select-support branch
Updated experimental builds for users to test. The builds are available at Blender Builds - blender.org under branch names :
soc-2021-uv-editor-improvements
soc-2021-uv-edge-select-support
Notable change : Subdividing grid for the UV editor now starts with a size of 8x8 (previously 4x4) and zooming in will further subdivide each grid division into smaller 8x8 grid units.
Plans for final week : 16 August to 23 August
Prepare for final GSoC evaluations
Continue with cleanup and fixes
Prepare patches for code submission (both soc branches)
