From c6a5a778c99d24b3a147cb88d4343f1f8fd088d2 Mon Sep 17 00:00:00 2001
From: Noeri Huisman <8823461+mrxz@users.noreply.github.com>
Date: Tue, 29 Jul 2025 09:50:09 +0200
Subject: [PATCH] Add support for orthographic rendering

---
 src/shaders/splatVertex.glsl | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/shaders/splatVertex.glsl b/src/shaders/splatVertex.glsl
index 0162293..c246064 100644
--- a/src/shaders/splatVertex.glsl
+++ b/src/shaders/splatVertex.glsl
@@ -131,14 +131,24 @@ void main() {
     // Compute the Jacobian of the splat's projection at its center
     vec2 scaledRenderSize = renderSize * focalAdjustment;
     vec2 focal = 0.5 * scaledRenderSize * vec2(projectionMatrix[0][0], projectionMatrix[1][1]);
-    float invZ = 1.0 / viewCenter.z;
-    vec2 J1 = focal * invZ;
-    vec2 J2 = -(J1 * viewCenter.xy) * invZ;
-    mat3 J = mat3(
-        J1.x, 0.0, J2.x,
-        0.0, J1.y, J2.y,
-        0.0, 0.0, 0.0
-    );
+
+    mat3 J;
+    if(isOrthographic) {
+        J = mat3(
+            focal.x, 0.0, 0.0,
+            0.0, focal.y, 0.0,
+            0.0, 0.0, 0.0
+        );
+    } else {
+        float invZ = 1.0 / viewCenter.z;
+        vec2 J1 = focal * invZ;
+        vec2 J2 = -(J1 * viewCenter.xy) * invZ;
+        J = mat3(
+            J1.x, 0.0, J2.x,
+            0.0, J1.y, J2.y,
+            0.0, 0.0, 0.0
+        );
+    }
 
     // Compute the 2D covariance by projecting the 3D covariance
     // and picking out the XY plane components.