Hair Particles Not Adopting The Colour Of The Surface They Are On (when named UVMap node is used) #71532

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Muhammad Ahmed · 2019-11-13T07:47:37+01:00

Muhammad Ahmed commented

2019-11-13 07:47:37 +01:00

System Information
Operating system: Windows 10
Graphics card: AMD Radeon R5 M335

Blender Version
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-12 13:28, hash: 1252577580, type: Release build date: 2019-11-13, 00:02:33
Worked: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f5449, type: build date: 2019-07-29, 09:44 AM

Short description of error
Hair particles do not adopt the colour of the portion of the surface they are on. I am using an image texture with 2 colours on a plane, but they are not shaded with the colour of the portion they are on. This is only happening on Eevee. It works fine on cycles. It also works fine on blender 2.80, even on Eevee. This problem is only in blender 2.81. Thank You for reviewing my bug report.

Exact steps for others to reproduce the error
I have attached the blend file, along with two images, one rendered in blender 2.81 which shows the problem, & the other in blender 2.80 which works correctly. Thank You.

Steps:
1- Create a plane
2- Add a material with an Image texture with multiple colours using a UV map, plugged into a principled shader node
3- Add a Hair Particle system
4- Under Render tab of particle system, select the material that was created
5 -Render the Image

Thank You
HairBugDemonstration.blend

**System Information** Operating system: Windows 10 Graphics card: AMD Radeon R5 M335 **Blender Version** Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-12 13:28, hash: 125257758007, type: Release build date: 2019-11-13, 00:02:33 Worked: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f54494e, type: build date: 2019-07-29, 09:44 AM **Short description of error** Hair particles do not adopt the colour of the portion of the surface they are on. I am using an image texture with 2 colours on a plane, but they are not shaded with the colour of the portion they are on. This is only happening on Eevee. It works fine on cycles. It also works fine on blender 2.80, even on Eevee. This problem is only in blender 2.81. Thank You for reviewing my bug report. **Exact steps for others to reproduce the error** I have attached the blend file, along with two images, one rendered in blender 2.81 which shows the problem, & the other in blender 2.80 which works correctly. Thank You. Steps: 1- Create a plane 2- Add a material with an Image texture with multiple colours using a UV map, plugged into a principled shader node 3- Add a Hair Particle system 4- Under Render tab of particle system, select the material that was created 5 -Render the Image Thank You [HairBugDemonstration.blend](https://archive.blender.org/developer/F8056829/HairBugDemonstration.blend) ![Blender 2-80 render.png](https://archive.blender.org/developer/F8056835/Blender_2-80_render.png) ![Blender 2-81 render.png](https://archive.blender.org/developer/F8056845/Blender_2-81_render.png)

Muhammad Ahmed commented

2019-11-13 07:47:37 +01:00

Added subscriber: @awo

blender-admin commented

2019-11-13 07:47:37 +01:00

#72395 was marked as duplicate of this issue

blender-admin commented

2019-11-13 07:47:37 +01:00

#72183 was marked as duplicate of this issue

Philipp Oeser commented

2019-11-14 10:32:20 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2019-11-14 10:32:20 +01:00

Confirmed, checking...

Philipp Oeser commented

2019-11-14 10:54:54 +01:00

This is an Eevee only problem.
This has to do with the UVMap node.

if you use a Texture Coordinate Node (use the UV output) instead it works
if you use the UVMap node (without specifiying an actual UV layer -- leave it empty) it also works

checking further...

This is an Eevee only problem. This has to do with the `UVMap` node. - if you use a `Texture Coordinate` Node (use the UV output) instead it works - if you use the UVMap node (without specifiying an actual UV layer -- leave it empty) it also works checking further...

Philipp Oeser self-assigned this 2019-11-14 14:02:35 +01:00

Philipp Oeser commented

2019-11-14 14:02:35 +01:00

Caused by deb5416a1a, think I can fix.

Caused by deb5416a1a, think I can fix.

Philipp Oeser removed their assignment 2019-11-14 15:02:16 +01:00

Clément Foucault was assigned by Philipp Oeser

2019-11-14 15:02:16 +01:00

Philipp Oeser commented

2019-11-14 15:02:16 +01:00

Added subscriber: @fclem

Philipp Oeser commented

2019-11-14 15:02:16 +01:00

@fclem: I thought I was on the right path with the following, but spoke too soon...

P1163: T71532_snippet



diff --git a/source/blender/draw/intern/draw_cache_impl_particles.c b/source/blender/draw/intern/draw_cache_impl_particles.c
index 3c586e6daec..4b5173a8d17 100644
--- a/source/blender/draw/intern/draw_cache_impl_particles.c
+++ b/source/blender/draw/intern/draw_cache_impl_particles.c
@@ -894,11 +894,13 @@ static void particle_batch_cache_ensure_procedural_strand_data(PTCacheEdit *edit
     GPU_vertbuf_data_alloc(cache->proc_uv_buf- [x], cache->strands_len);
     GPU_vertbuf_attr_get_raw_data(cache->proc_uv_buf- [x], uv_id, &uv_step[i]);
 
-    const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i);
-    uint hash = BLI_ghashutil_strhash_p(name);
+    char attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME];
+    const char *layer_name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i);
+    GPU_vertformat_safe_attrib_name(layer_name, attr_safe_name, GPU_MAX_SAFE_ATTRIB_NAME);
+
     int n = 0;
-    BLI_snprintf(cache->uv_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "u%u", hash);
-    BLI_snprintf(cache->uv_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "a%u", hash);
+    BLI_snprintf(cache->uv_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "u%s", attr_safe_name);
+    BLI_snprintf(cache->uv_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "a%s", attr_safe_name);
 
     if (i == active_uv) {
       BLI_strncpy(cache->uv_layer_names- [x][n++], "au", MAX_LAYER_NAME_LEN);
@@ -913,14 +915,16 @@ static void particle_batch_cache_ensure_procedural_strand_data(PTCacheEdit *edit
     GPU_vertbuf_data_alloc(cache->proc_col_buf- [x], cache->strands_len);
     GPU_vertbuf_attr_get_raw_data(cache->proc_col_buf- [x], col_id, &col_step[i]);
 
-    const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPCOL, i);
-    uint hash = BLI_ghashutil_strhash_p(name);
+    char attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME];
+    const char *layer_name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPCOL, i);
+    GPU_vertformat_safe_attrib_name(layer_name, attr_safe_name, GPU_MAX_SAFE_ATTRIB_NAME);
+
     int n = 0;
-    BLI_snprintf(cache->col_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "c%u", hash);
+    BLI_snprintf(cache->col_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "c%s", attr_safe_name);
 
     /* We only do vcols auto name that are not overridden by uvs */
-    if (CustomData_get_named_layer_index(&psmd->mesh_final->ldata, CD_MLOOPUV, name) == -1) {
-      BLI_snprintf(cache->col_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "a%u", hash);
+    if (CustomData_get_named_layer_index(&psmd->mesh_final->ldata, CD_MLOOPUV, layer_name) == -1) {
+      BLI_snprintf(cache->col_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "a%s", attr_safe_name);
     }
 
     if (i == active_col) {
@@ -1176,23 +1180,26 @@ static void particle_batch_cache_ensure_pos_and_seg(PTCacheEdit *edit,
     col_id = MEM_mallocN(sizeof(*col_id) * num_col_layers, "Col attr format");
 
     for (int i = 0; i < num_uv_layers; i++) {
-      const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i);
-      char uuid[32];
+      const char *layer_name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i);
+      char attr_name[32], attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME];
+      GPU_vertformat_safe_attrib_name(layer_name, attr_safe_name, GPU_MAX_SAFE_ATTRIB_NAME);
 
-      BLI_snprintf(uuid, sizeof(uuid), "u%u", BLI_ghashutil_strhash_p(name));
-      uv_id- [x] = GPU_vertformat_attr_add(&format, uuid, GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
+      BLI_snprintf(attr_name, sizeof(attr_name), "u%s", attr_safe_name);
+      uv_id- [x] = GPU_vertformat_attr_add(&format, attr_name, GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
 
       if (i == active_uv) {
         GPU_vertformat_alias_add(&format, "u");
       }
     }
 
-    for (int i = 0; i < num_uv_layers; i++) {
-      const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i);
-      char uuid[32];
+    // shouldnt this be vcols?
+    for (int i = 0; i < num_col_layers; i++) {
+      const char *layer_name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPCOL, i);
+      char attr_name[32], attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME];
+      GPU_vertformat_safe_attrib_name(layer_name, attr_safe_name, GPU_MAX_SAFE_ATTRIB_NAME);
 
-      BLI_snprintf(uuid, sizeof(uuid), "c%u", BLI_ghashutil_strhash_p(name));
-      col_id- [x] = GPU_vertformat_attr_add(&format, uuid, GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
+      BLI_snprintf(attr_name, sizeof(attr_name), "c%s", attr_safe_name);
+      col_id- [x] = GPU_vertformat_attr_add(&format, attr_name, GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
 
       if (i == active_col) {
         GPU_vertformat_alias_add(&format, "c");

could you takke over?

@fclem: I thought I was on the right path with the following, but spoke too soon... [P1163: T71532_snippet](https://archive.blender.org/developer/P1163.txt) ``` diff --git a/source/blender/draw/intern/draw_cache_impl_particles.c b/source/blender/draw/intern/draw_cache_impl_particles.c index 3c586e6daec..4b5173a8d17 100644 --- a/source/blender/draw/intern/draw_cache_impl_particles.c +++ b/source/blender/draw/intern/draw_cache_impl_particles.c @@ -894,11 +894,13 @@ static void particle_batch_cache_ensure_procedural_strand_data(PTCacheEdit *edit GPU_vertbuf_data_alloc(cache->proc_uv_buf- [x], cache->strands_len); GPU_vertbuf_attr_get_raw_data(cache->proc_uv_buf- [x], uv_id, &uv_step[i]); - const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i); - uint hash = BLI_ghashutil_strhash_p(name); + char attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME]; + const char *layer_name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i); + GPU_vertformat_safe_attrib_name(layer_name, attr_safe_name, GPU_MAX_SAFE_ATTRIB_NAME); + int n = 0; - BLI_snprintf(cache->uv_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "u%u", hash); - BLI_snprintf(cache->uv_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "a%u", hash); + BLI_snprintf(cache->uv_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "u%s", attr_safe_name); + BLI_snprintf(cache->uv_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "a%s", attr_safe_name); if (i == active_uv) { BLI_strncpy(cache->uv_layer_names- [x][n++], "au", MAX_LAYER_NAME_LEN); @@ -913,14 +915,16 @@ static void particle_batch_cache_ensure_procedural_strand_data(PTCacheEdit *edit GPU_vertbuf_data_alloc(cache->proc_col_buf- [x], cache->strands_len); GPU_vertbuf_attr_get_raw_data(cache->proc_col_buf- [x], col_id, &col_step[i]); - const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPCOL, i); - uint hash = BLI_ghashutil_strhash_p(name); + char attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME]; + const char *layer_name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPCOL, i); + GPU_vertformat_safe_attrib_name(layer_name, attr_safe_name, GPU_MAX_SAFE_ATTRIB_NAME); + int n = 0; - BLI_snprintf(cache->col_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "c%u", hash); + BLI_snprintf(cache->col_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "c%s", attr_safe_name); /* We only do vcols auto name that are not overridden by uvs */ - if (CustomData_get_named_layer_index(&psmd->mesh_final->ldata, CD_MLOOPUV, name) == -1) { - BLI_snprintf(cache->col_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "a%u", hash); + if (CustomData_get_named_layer_index(&psmd->mesh_final->ldata, CD_MLOOPUV, layer_name) == -1) { + BLI_snprintf(cache->col_layer_names- [x][n++], MAX_LAYER_NAME_LEN, "a%s", attr_safe_name); } if (i == active_col) { @@ -1176,23 +1180,26 @@ static void particle_batch_cache_ensure_pos_and_seg(PTCacheEdit *edit, col_id = MEM_mallocN(sizeof(*col_id) * num_col_layers, "Col attr format"); for (int i = 0; i < num_uv_layers; i++) { - const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i); - char uuid[32]; + const char *layer_name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i); + char attr_name[32], attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME]; + GPU_vertformat_safe_attrib_name(layer_name, attr_safe_name, GPU_MAX_SAFE_ATTRIB_NAME); - BLI_snprintf(uuid, sizeof(uuid), "u%u", BLI_ghashutil_strhash_p(name)); - uv_id- [x] = GPU_vertformat_attr_add(&format, uuid, GPU_COMP_F32, 2, GPU_FETCH_FLOAT); + BLI_snprintf(attr_name, sizeof(attr_name), "u%s", attr_safe_name); + uv_id- [x] = GPU_vertformat_attr_add(&format, attr_name, GPU_COMP_F32, 2, GPU_FETCH_FLOAT); if (i == active_uv) { GPU_vertformat_alias_add(&format, "u"); } } - for (int i = 0; i < num_uv_layers; i++) { - const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i); - char uuid[32]; + // shouldnt this be vcols? + for (int i = 0; i < num_col_layers; i++) { + const char *layer_name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPCOL, i); + char attr_name[32], attr_safe_name[GPU_MAX_SAFE_ATTRIB_NAME]; + GPU_vertformat_safe_attrib_name(layer_name, attr_safe_name, GPU_MAX_SAFE_ATTRIB_NAME); - BLI_snprintf(uuid, sizeof(uuid), "c%u", BLI_ghashutil_strhash_p(name)); - col_id- [x] = GPU_vertformat_attr_add(&format, uuid, GPU_COMP_F32, 2, GPU_FETCH_FLOAT); + BLI_snprintf(attr_name, sizeof(attr_name), "c%s", attr_safe_name); + col_id- [x] = GPU_vertformat_attr_add(&format, attr_name, GPU_COMP_F32, 2, GPU_FETCH_FLOAT); if (i == active_col) { GPU_vertformat_alias_add(&format, "c"); ``` could you takke over?

Philipp Oeser changed title from ~~Hair Particles Not Adopting The Colour Of The Surface They Are On~~ to Hair Particles Not Adopting The Colour Of The Surface They Are On (when named UVMap node is used)

2019-11-14 15:02:53 +01:00

Philipp Oeser commented

2019-12-05 10:13:00 +01:00

Added subscriber: @rayshin