Add Cone and Cylinder shapes to FogVolume

This complements the existing Ellipsoid and Box local fog shapes.

This can be used to represent a light cone coming from a SpotLight.

5 files changed, 31 insertions, 3 deletions

diff --git a/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp b/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp
index 9e798e8b6d..85a132e6df 100644
--- a/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp
+++ b/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp
@@ -4365,7 +4365,8 @@ void RendererSceneRenderRD::_update_volumetric_fog(RID p_render_buffers, RID p_e
 			RS::FogVolumeShape volume_type = storage->fog_volume_get_shape(fog_volume);
 			Vector3 extents = storage->fog_volume_get_extents(fog_volume);
 
-			if (volume_type == RS::FOG_VOLUME_SHAPE_BOX || volume_type == RS::FOG_VOLUME_SHAPE_ELLIPSOID) {
+			if (volume_type != RS::FOG_VOLUME_SHAPE_WORLD) {
+				// Local fog volume.
 				Vector3i points[8];
 				points[0] = _point_get_position_in_froxel_volume(fog_volume_instance->transform.xform(Vector3(extents.x, extents.y, extents.z)), fog_end, fog_near_size, fog_far_size, env->volumetric_fog_detail_spread, Vector3(rb->volumetric_fog->width, rb->volumetric_fog->height, rb->volumetric_fog->depth), p_cam_transform);
 				points[1] = _point_get_position_in_froxel_volume(fog_volume_instance->transform.xform(Vector3(-extents.x, extents.y, extents.z)), fog_end, fog_near_size, fog_far_size, env->volumetric_fog_detail_spread, Vector3(rb->volumetric_fog->width, rb->volumetric_fog->height, rb->volumetric_fog->depth), p_cam_transform);
diff --git a/servers/rendering/renderer_rd/renderer_storage_rd.cpp b/servers/rendering/renderer_rd/renderer_storage_rd.cpp
index cf642c38c9..1b9e0faa00 100644
--- a/servers/rendering/renderer_rd/renderer_storage_rd.cpp
+++ b/servers/rendering/renderer_rd/renderer_storage_rd.cpp
@@ -97,6 +97,8 @@ AABB RendererStorageRD::fog_volume_get_aabb(RID p_fog_volume) const {
 
 	switch (fog_volume->shape) {
 		case RS::FOG_VOLUME_SHAPE_ELLIPSOID:
+		case RS::FOG_VOLUME_SHAPE_CONE:
+		case RS::FOG_VOLUME_SHAPE_CYLINDER:
 		case RS::FOG_VOLUME_SHAPE_BOX: {
 			AABB aabb;
 			aabb.position = -fog_volume->extents;
diff --git a/servers/rendering/renderer_rd/shaders/volumetric_fog.glsl b/servers/rendering/renderer_rd/shaders/volumetric_fog.glsl
index a2a4c91894..eee609fb48 100644
--- a/servers/rendering/renderer_rd/shaders/volumetric_fog.glsl
+++ b/servers/rendering/renderer_rd/shaders/volumetric_fog.glsl
@@ -186,12 +186,31 @@ void main() {
 
 	float sdf = -1.0;
 	if (params.shape == 0) {
-		//Ellipsoid
+		// Ellipsoid
 		// https://www.shadertoy.com/view/tdS3DG
 		float k0 = length(local_pos.xyz / params.extents);
 		float k1 = length(local_pos.xyz / (params.extents * params.extents));
 		sdf = k0 * (k0 - 1.0) / k1;
 	} else if (params.shape == 1) {
+		// Cone
+		// https://iquilezles.org/www/articles/distfunctions/distfunctions.htm
+
+		// Compute the cone angle automatically to fit within the volume's extents.
+		float inv_height = 1.0 / max(0.001, params.extents.y);
+		float radius = 1.0 / max(0.001, (min(params.extents.x, params.extents.z) * 0.5));
+		float hypotenuse = sqrt(radius * radius + inv_height * inv_height);
+		float rsin = radius / hypotenuse;
+		float rcos = inv_height / hypotenuse;
+		vec2 c = vec2(rsin, rcos);
+
+		float q = length(local_pos.xz);
+		sdf = max(dot(c, vec2(q, local_pos.y - params.extents.y)), -params.extents.y - local_pos.y);
+	} else if (params.shape == 2) {
+		// Cylinder
+		// https://iquilezles.org/www/articles/distfunctions/distfunctions.htm
+		vec2 d = abs(vec2(length(local_pos.xz), local_pos.y)) - vec2(min(params.extents.x, params.extents.z), params.extents.y);
+		sdf = min(max(d.x, d.y), 0.0) + length(max(d, 0.0));
+	} else if (params.shape == 3) {
 		// Box
 		// https://iquilezles.org/www/articles/distfunctions/distfunctions.htm
 		vec3 q = abs(local_pos.xyz) - params.extents;
@@ -199,7 +218,7 @@ void main() {
 	}
 
 	float cull_mask = 1.0; //used to cull cells that do not contribute
-	if (params.shape <= 1) {
+	if (params.shape <= 3) {
 #ifndef SDF_USED
 		cull_mask = 1.0 - smoothstep(-0.1, 0.0, sdf);
 #endif
diff --git a/servers/rendering_server.cpp b/servers/rendering_server.cpp
index 766ca88e34..8f285aeaad 100644
--- a/servers/rendering_server.cpp
+++ b/servers/rendering_server.cpp
@@ -2140,8 +2140,11 @@ void RenderingServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("fog_volume_set_material", "fog_volume", "material"), &RenderingServer::fog_volume_set_material);
 
 	BIND_ENUM_CONSTANT(FOG_VOLUME_SHAPE_ELLIPSOID);
+	BIND_ENUM_CONSTANT(FOG_VOLUME_SHAPE_CONE);
+	BIND_ENUM_CONSTANT(FOG_VOLUME_SHAPE_CYLINDER);
 	BIND_ENUM_CONSTANT(FOG_VOLUME_SHAPE_BOX);
 	BIND_ENUM_CONSTANT(FOG_VOLUME_SHAPE_WORLD);
+	BIND_ENUM_CONSTANT(FOG_VOLUME_SHAPE_MAX);
 
 	/* VISIBILITY NOTIFIER */
 
diff --git a/servers/rendering_server.h b/servers/rendering_server.h
index d622571a47..1ac48053d8 100644
--- a/servers/rendering_server.h
+++ b/servers/rendering_server.h
@@ -724,8 +724,11 @@ public:
 
 	enum FogVolumeShape {
 		FOG_VOLUME_SHAPE_ELLIPSOID,
+		FOG_VOLUME_SHAPE_CONE,
+		FOG_VOLUME_SHAPE_CYLINDER,
 		FOG_VOLUME_SHAPE_BOX,
 		FOG_VOLUME_SHAPE_WORLD,
+		FOG_VOLUME_SHAPE_MAX,
 	};
 
 	virtual void fog_volume_set_shape(RID p_fog_volume, FogVolumeShape p_shape) = 0;