Commit A of the instancing migration (Phase 3a). The streamer now runs
the iterator with use-world-coords=false and dedupes by the geometry's
representation id, emitting a MeshChunk once per unique geometry and an
InstanceChunk per placement. The viewport keeps geometry in local
coordinates (28 B/vertex, down from 32) and applies the per-instance
transform in the vertex shader via an std430 SSBO indexed by
gl_InstanceID + a per-draw uniform offset. After streaming finishes
finalizeModel() stable-sorts instances by mesh_id, assigns each mesh a
contiguous range, and uploads the SSBO; render then issues one
glDrawElementsInstancedBaseVertex per mesh.
BvhAccel is reshaped to operate on a generic BvhItem (world AABB +
model_id) so it can drive instance-level culling, but the path is not
wired in yet -- every instance is drawn every frame in this commit.
Progressive-during-streaming rendering is likewise disabled: a model
appears when its SSBO is uploaded, not incrementally. Sidecar cache
is stubbed (reads miss, writes are no-ops); the v4 on-disk format with
MeshInfo + InstanceGpu sections lands in Commit B.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Per-second frame log reports fps/ms, visible/total object & triangle
ratios, VRAM breakdown (VBO+EBO), model count, and pending uploads.
Upload-complete log includes per-model VBO/EBO MB and scene total VRAM.
Streamer runs an instancing analysis keyed on geom.id(): total shapes,
unique representations, dedup ratio, theoretical VBO/EBO/SSBO sizes if
instanced, potential savings, and top-5 most-duplicated representations.
Used to validate whether GPU instancing is worth the architectural
rewrite for a given dataset.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Introduce ModelHandle and per-model GeometryStreamers so multiple IFC
files can be loaded simultaneously. Object IDs are globally unique
(monotonically increasing across models). File picker is now multiselect.
Each model gets a top-level tree node. Property lookup uses the correct
model's ifcopenshell::file. ViewportWindow supports hide/show/remove
per model via model_id filtering in the frustum cull pass.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Dion Moult