diff --git a/src/bbox.rs b/src/bbox.rs
index 68e0c4a..fa5e8ea 100644
--- a/src/bbox.rs
+++ b/src/bbox.rs
@@ -7,7 +7,7 @@ use std::{
 
 use crate::{
     lerp::{lerp, lerp_slice, Lerp},
-    math::{fast_minf32, Point, Vector, Xform, XformFull},
+    math::{fast_minf32, Point, Vector, Xform},
 };
 
 const BBOX_MAXT_ADJUST: f32 = 1.000_000_24;
@@ -57,7 +57,7 @@ impl BBox {
     // Creates a new BBox transformed from its local space to the
     // given space.
     #[must_use]
-    pub fn xform(&self, xform: &XformFull) -> BBox {
+    pub fn xform(&self, xform: &Xform) -> BBox {
         // BBox corners
         let vs = [
             Point::new(self.min.x(), self.min.y(), self.min.z()),
@@ -73,7 +73,7 @@ impl BBox {
         // Transform BBox corners and make new bbox
         let mut b = BBox::new();
         for v in &vs {
-            let v = v.xform(&xform);
+            let v = v.xform(xform);
             b.min = v.min(b.min);
             b.max = v.max(b.max);
         }
@@ -141,11 +141,7 @@ impl Lerp for BBox {
     }
 }
 
-pub fn transform_bbox_slice_from(
-    bbs_in: &[BBox],
-    xforms: &[Xform],
-    bbs_out: &mut Vec<BBox>,
-) -> Result<(), ()> {
+pub fn transform_bbox_slice_from(bbs_in: &[BBox], xforms: &[Xform], bbs_out: &mut Vec<BBox>) {
     bbs_out.clear();
 
     // Transform the bounding boxes
@@ -153,19 +149,17 @@ pub fn transform_bbox_slice_from(
         bbs_out.extend_from_slice(bbs_in);
     } else if bbs_in.len() == xforms.len() {
         for (bb, xf) in Iterator::zip(bbs_in.iter(), xforms.iter()) {
-            bbs_out.push(bb.xform(&xf.into_full().ok_or(())?));
+            bbs_out.push(bb.xform(&xf));
         }
     } else if bbs_in.len() > xforms.len() {
         let s = (bbs_in.len() - 1) as f32;
         for (i, bb) in bbs_in.iter().enumerate() {
-            bbs_out.push(bb.xform(&lerp_slice(xforms, i as f32 / s).into_full().ok_or(())?));
+            bbs_out.push(bb.xform(&lerp_slice(xforms, i as f32 / s)));
         }
     } else if bbs_in.len() < xforms.len() {
         let s = (xforms.len() - 1) as f32;
         for (i, xf) in xforms.iter().enumerate() {
-            bbs_out.push(lerp_slice(bbs_in, i as f32 / s).xform(&xf.into_full().ok_or(())?));
+            bbs_out.push(lerp_slice(bbs_in, i as f32 / s).xform(&xf));
         }
     }
-
-    Ok(())
 }
diff --git a/src/camera.rs b/src/camera.rs
index 4f65a7f..7dbd3b9 100644
--- a/src/camera.rs
+++ b/src/camera.rs
@@ -73,7 +73,7 @@ impl<'a> Camera<'a> {
 
     pub fn generate_ray(&self, x: f32, y: f32, time: f32, wavelength: f32, u: f32, v: f32) -> Ray {
         // Get time-interpolated camera settings
-        let transform = lerp_slice(self.transforms, time).into_full_fast().unwrap();
+        let transform = lerp_slice(self.transforms, time).to_full_fast().unwrap();
         let tfov = lerp_slice(self.tfovs, time);
         let aperture_radius = lerp_slice(self.aperture_radii, time);
         let focus_distance = lerp_slice(self.focus_distances, time);
diff --git a/src/light/rectangle_light.rs b/src/light/rectangle_light.rs
index 231e687..73c3b14 100644
--- a/src/light/rectangle_light.rs
+++ b/src/light/rectangle_light.rs
@@ -271,7 +271,7 @@ impl<'a> Surface for RectangleLight<'a> {
             let dim = lerp_slice(self.dimensions, time);
             let xform = lerp_slice(space, time);
 
-            let space = if let Some(xform) = xform.into_full() {
+            let space = if let Some(xform) = xform.to_full() {
                 xform
             } else {
                 return;
diff --git a/src/light/sphere_light.rs b/src/light/sphere_light.rs
index 9ff1664..8da8515 100644
--- a/src/light/sphere_light.rs
+++ b/src/light/sphere_light.rs
@@ -215,7 +215,7 @@ impl<'a> Surface for SphereLight<'a> {
             let time = rays.time(ray_idx);
 
             // Get the transform space
-            let xform = if let Some(xform) = lerp_slice(space, time).into_full() {
+            let xform = if let Some(xform) = lerp_slice(space, time).to_full() {
                 xform
             } else {
                 return;
diff --git a/src/math.rs b/src/math.rs
index 2fd40da..705f8ee 100644
--- a/src/math.rs
+++ b/src/math.rs
@@ -3,8 +3,8 @@
 use std::f32;
 
 pub use rmath::{
-    cross, cross_fast, dot, dot_fast, wide4::Float4, CrossProduct, DotProduct, Normal, Point,
-    Vector, Xform, XformFull,
+    cross, cross_fast, dot, dot_fast, wide4::Float4, AsXform, CrossProduct, DotProduct, Normal,
+    Point, Vector, Xform, XformFull,
 };
 
 /// Clamps a value between a min and max.
diff --git a/src/scene/assembly.rs b/src/scene/assembly.rs
index 2f47cfe..1e6e98c 100644
--- a/src/scene/assembly.rs
+++ b/src/scene/assembly.rs
@@ -58,7 +58,7 @@ impl<'a> Assembly<'a> {
         } = *intr
         {
             let sel_xform = if !xform_stack.top().is_empty() {
-                if let Some(xform) = lerp_slice(xform_stack.top(), time).into_full() {
+                if let Some(xform) = lerp_slice(xform_stack.top(), time).to_full() {
                     xform
                 } else {
                     return None;
@@ -98,7 +98,7 @@ impl<'a> Assembly<'a> {
                                         Xform::identity()
                                     }
                                 }
-                                .into_full();
+                                .to_full();
 
                                 // Sample the light
                                 if let Some(xform) = xform {
@@ -390,7 +390,7 @@ impl<'a> AssemblyBuilder<'a> {
             // Transform the bounding boxes, if necessary
             if let Some((xstart, xend)) = inst.transform_indices {
                 let xf = &self.xforms[xstart..xend];
-                transform_bbox_slice_from(&bbs, xf, &mut bbs2).unwrap();
+                transform_bbox_slice_from(&bbs, xf, &mut bbs2);
             } else {
                 bbs2.clear();
                 bbs2.extend(bbs);
diff --git a/src/surface/micropoly_batch.rs b/src/surface/micropoly_batch.rs
index 9a95e31..cb7e6c4 100644
--- a/src/surface/micropoly_batch.rs
+++ b/src/surface/micropoly_batch.rs
@@ -9,7 +9,7 @@ use crate::{
     bbox::BBox,
     boundable::Boundable,
     lerp::lerp_slice,
-    math::{cross, dot, Normal, Point, Xform, XformFull},
+    math::{cross, dot, Normal, Point, Xform},
     ray::{RayBatch, RayStack},
     shading::SurfaceClosure,
 };
@@ -154,13 +154,9 @@ impl<'a> MicropolyBatch<'a> {
     ) {
         // Precalculate transform for non-motion blur cases
         let static_mat_space = if space.len() == 1 {
-            if let Some(xform) = space[0].into_full() {
-                xform
-            } else {
-                return;
-            }
+            space[0]
         } else {
-            XformFull::identity()
+            Xform::identity()
         };
 
         self.accel
@@ -209,11 +205,7 @@ impl<'a> MicropolyBatch<'a> {
                     // Calculate the ray space, if necessary.
                     let mat_space = if space.len() > 1 {
                         // Per-ray transform, for motion blur
-                        if let Some(xform) = lerp_slice(space, ray_time).into_full() {
-                            xform
-                        } else {
-                            return;
-                        }
+                        lerp_slice(space, ray_time)
                     } else {
                         static_mat_space
                     };
@@ -292,6 +284,13 @@ impl<'a> MicropolyBatch<'a> {
 
                     // Calculate intersection data if necessary.
                     if non_shadow_hit {
+                        // Get the full space data.
+                        let mat_space = if let Some(space) = mat_space.to_full() {
+                            space
+                        } else {
+                            return;
+                        };
+
                         let hit_tri = unsafe { hit_tri.assume_init() };
                         let hit_tri_indices = unsafe { hit_tri_indices.assume_init() };
                         let (t, b0, b1, b2) = unsafe { hit_tri_data.assume_init() };
diff --git a/src/surface/triangle_mesh.rs b/src/surface/triangle_mesh.rs
index f41ca6f..6e3546a 100644
--- a/src/surface/triangle_mesh.rs
+++ b/src/surface/triangle_mesh.rs
@@ -7,7 +7,7 @@ use crate::{
     bbox::BBox,
     boundable::Boundable,
     lerp::lerp_slice,
-    math::{cross, dot, Normal, Point, Xform, XformFull},
+    math::{cross, dot, Normal, Point, Xform},
     ray::{RayBatch, RayStack},
     shading::SurfaceShader,
 };
@@ -132,13 +132,9 @@ impl<'a> Surface for TriangleMesh<'a> {
     ) {
         // Precalculate transform for non-motion blur cases
         let static_mat_space = if space.len() == 1 {
-            if let Some(xform) = lerp_slice(space, 0.0).into_full() {
-                xform
-            } else {
-                return;
-            }
+            space[0]
         } else {
-            XformFull::identity()
+            Xform::identity()
         };
 
         self.accel
@@ -187,11 +183,7 @@ impl<'a> Surface for TriangleMesh<'a> {
                     // Calculate the ray space, if necessary.
                     let mat_space = if space.len() > 1 {
                         // Per-ray transform, for motion blur
-                        if let Some(xform) = lerp_slice(space, ray_time).into_full() {
-                            xform
-                        } else {
-                            return;
-                        }
+                        lerp_slice(space, ray_time)
                     } else {
                         static_mat_space
                     };
@@ -270,6 +262,13 @@ impl<'a> Surface for TriangleMesh<'a> {
 
                     // Calculate intersection data if necessary.
                     if non_shadow_hit {
+                        // Get the full space data.
+                        let mat_space = if let Some(space) = mat_space.to_full() {
+                            space
+                        } else {
+                            return;
+                        };
+
                         let hit_tri = unsafe { hit_tri.assume_init() };
                         let (t, b0, b1, b2) = unsafe { hit_tri_data.assume_init() };
 
diff --git a/src/tracer.rs b/src/tracer.rs
index 88833d3..5a3d834 100644
--- a/src/tracer.rs
+++ b/src/tracer.rs
@@ -103,16 +103,27 @@ impl<'a> TracerInner<'a> {
                     // Do transforms
                     // TODO: re-divide rays based on direction (maybe?).
                     let xforms = self.xform_stack.top();
+                    let static_xform = if xforms.len() == 1 {
+                        if let Some(xform) = xforms[0].to_full() {
+                            Some(xform)
+                        } else {
+                            return;
+                        }
+                    } else if xforms.len() == 0 {
+                        Some(XformFull::identity())
+                    } else {
+                        None
+                    };
                     ray_stack.do_next_task(|ray_idx| {
                         let t = rays.time(ray_idx);
                         rays.update_local(
                             ray_idx,
-                            &if let Some(xform) = lerp_slice(xforms, t).into_full() {
-                                xform
-                            } else {
-                                // TODO: filter out ray instead.
-                                XformFull::identity()
-                            },
+                            &static_xform.unwrap_or_else(|| {
+                                lerp_slice(xforms, t).to_full().unwrap_or(
+                                    // TODO: filter out ray instead.
+                                    XformFull::identity(),
+                                )
+                            }),
                         );
                     });
                     ray_stack.duplicate_next_task();
@@ -142,17 +153,28 @@ impl<'a> TracerInner<'a> {
 
                     // Undo transforms
                     let xforms = self.xform_stack.top();
+                    let static_xform = if xforms.len() == 1 {
+                        if let Some(xform) = xforms[0].to_full() {
+                            Some(xform)
+                        } else {
+                            return;
+                        }
+                    } else if xforms.len() == 0 {
+                        Some(XformFull::identity())
+                    } else {
+                        None
+                    };
                     if !xforms.is_empty() {
                         ray_stack.pop_do_next_task(|ray_idx| {
                             let t = rays.time(ray_idx);
                             rays.update_local(
                                 ray_idx,
-                                &if let Some(xform) = lerp_slice(xforms, t).into_full() {
-                                    xform
-                                } else {
-                                    // TODO: filter out ray instead.
-                                    XformFull::identity()
-                                },
+                                &static_xform.unwrap_or_else(|| {
+                                    lerp_slice(xforms, t).to_full().unwrap_or(
+                                        // TODO: filter out ray instead.
+                                        XformFull::identity(),
+                                    )
+                                }),
                             );
                         });
                     } else {