diff --git a/index.html b/index.html
index 74fdc533..afc98889 100644
--- a/index.html
+++ b/index.html
@@ -24,11 +24,9 @@
 
     <mc-diorama>
         <script type="text/mc-world">
-            p stone_bricks
             p stone
-            p deepslate
-            p stone_brick_stairs
-            p stone_brick_wall
+            p stone
+            p stone
         </script>
     </mc-diorama>
 
diff --git a/src/minerama.js b/src/minerama.js
index 4983c58c..768ba8ee 100644
--- a/src/minerama.js
+++ b/src/minerama.js
@@ -3,20 +3,39 @@ export class Renderer {
         this.canvas = document.createElement('canvas');
         this.canvas.style.display = 'none';
         document.body.appendChild(this.canvas);
-        this.gl = this.canvas.getContext('webgl2', {antialias: false, alpha: true})
+        this.gl = this.canvas.getContext('webgl2', {antialias: false, alpha: true});
     }
 }
 
 function renderVariantCondition(key) {
-    if (key) {
-        return key.split(',').map(
-            it => it.split("=")
-        ).map(
-            ([n, v]) => `state[${JSON.stringify(n)}] === ${JSON.stringify(v)}`
-        ).join(" && ")
-    } else {
-        return 'true';
+    return key.split(',')
+        .map(it => it.split("="))
+        .map(([n, v]) => `state[${JSON.stringify(n)}] === ${JSON.stringify(v)}`)
+        .join(" && ");
+}
+
+function renderWhenCondition(when) {
+    if (!when) return "true";
+
+    if (when["OR"]) {
+        return when["OR"]
+            .map(it => `(${renderWhenCondition(it)})`)
+            .join(" || ");
     }
+    if (when["AND"]) {
+        return when["AND"]
+            .map(it => `(${renderWhenCondition(it)})`)
+            .join(" && ")
+    }
+
+    if (Object.entries(when).length === 0) return 'true';
+
+    return Object.entries(when)
+        .map(([key, vals]) => vals.toString().split('|')
+            .map(val => `state[${JSON.stringify(key)}] === ${JSON.stringify(val)}`)
+            .join(' || '))
+        .map(it => `(${it})`)
+        .join(' && ');
 }
 
 function renderApply(data) {
@@ -34,12 +53,12 @@ function renderApply(data) {
             if (accum === total) {
                 parts.push(JSON.stringify(elem));
             } else {
-                parts.push(`(hash % ${total}) < ${accum} ? ${JSON.stringify(elem)} : `)
+                parts.push(`h < ${accum} ? ${JSON.stringify(elem)} : `);
             }
         }
-        return parts.join('');
+        return `(h => ${parts.join('')})(Math.abs(hash) % ${total})`;
     } else {
-        return JSON.stringify(data)
+        return JSON.stringify(data);
     }
 }
 
@@ -51,20 +70,66 @@ function renderBlockstateResolver(data) {
     const {variants, multipart} = data;
 
     if (variants) {
-        if (Object.keys(variants).length === 1 && variants[""]) {
-            return `return ${(renderApply(variants[""]))};`;
-        } else {
-            let cases = [];
-            for (const [key, defn] of Object.entries(variants)) {
-                cases.push(`if (${(renderVariantCondition(key))}) return ${(renderApply(defn))};`)
-            }
-            cases.push(`return {"model": ":missing"};`)
-            return cases.join('else ')
+        let cases = [];
+        for (const [key, apply] of Object.entries(variants)) {
+            if (!key || key === "normal") continue;
+            cases.push(`if (${(renderVariantCondition(key))}) return [${(renderApply(apply))}];`);
         }
+        let fallback = variants[""] ?? variants["normal"] ?? {"model": ":invalid"};
+        cases.push(`return [${renderApply(fallback)}]`)
+        return cases.join('else ');
     } else if (multipart) {
-        return 'console.warn("NOT IMPLEMENTED")'
+        const parts = [];
+        parts.push('const parts = [];')
+        for (const {when, apply} of multipart) {
+            parts.push(`if (${renderWhenCondition(when)}) parts.push(${renderApply(apply)});`);
+        }
+        parts.push("return parts;");
+        return parts.join('');
     } else {
-        console.warn('invalid blockstate', data)
+        console.warn('invalid blockstate', data);
+        return 'return [{"model": ":invalid"}]';
+    }
+}
+
+
+export class BlockstateResolver {
+    constructor() {
+        this.resolvers = new Map();
+        this.resolvers.set(':pending', (state, hash) => [{"model": ":pending"}]);
+        this.resolvers.set(':invalid', (state, hash) => [{"model": ":invalid"}]);
+
+        this.pending = new Map();
+
+        this.onResolve = undefined;
+    }
+
+    getResolver(id) {
+        id = id.includes(':') ? id : `minecraft:${id}`;
+        if (this.resolvers.has(id)) {
+            return this.resolvers.get(id);
+        }
+        if (!this.pending.has(id)) {
+            const [space, name] = id.split(':');
+            this.pending.set(id, fetch(`assets/${space}/blockstates/${name}.json`)
+                .then(res => res.json())
+                .then(data => {
+                    const source = renderBlockstateResolver(data);
+                    const resolver = new Function(`return function (state, hash) { ${source} }`)();
+                    this.resolvers.set(id, resolver);
+                    this.pending.delete(id);
+                    if (this.onResolve) {
+                        this.onResolve(id, resolver);
+                    }
+                })
+                .catch(reason => {
+                    this.resolvers.set(id, this.resolvers.get(':invalid'));
+                    this.pending.delete(id);
+                    console.log(`failed to resolve blockstate ${id}: ${reason}`)
+                })
+            )
+        }
+        return this.resolvers.get(':pending');
     }
 }
 
@@ -75,27 +140,30 @@ function renderBlockstateResolver(data) {
 async function parse(src) {
     const lines = src.replace(/#.*?(?:\n|$)/, '\n').trim().split(/(?:\n[ \t]*)+/);
 
-    for (const line of lines) {
-        const args = line.split(/[ \t]+/);
-        const cmd = args[0].toLowerCase();
+    let count = 0;
+    const res = new BlockstateResolver();
 
-        if (cmd === 'p') {
-            const block = args[1];
+    function ff() {
+        for (const line of lines) {
+            const args = line.split(/[ \t]+/);
+            const cmd = args[0].toLowerCase();
 
-            try {
-                const res = await fetch(`assets/minecraft/blockstates/${block}.json`);
-                let data = await res.json();
-                let resolver_src = renderBlockstateResolver(data);
-                // console.log(beautify.js(`${block} = (state, hash) => {${resolver_src}}`))
+            if (cmd === 'p') {
+                const id = args[1];
+                const hash = count;
+                count += 1;
 
-                let resolver = new Function("state", "hash", resolver_src);
-                console.log(resolver)
-
-            } catch (ex) {
-                console.warn(`Fetch for ${block} failed:`, ex);
+                console.log(id, JSON.stringify(res.getResolver(id)({}, hash)));
             }
         }
     }
+
+    res.onResolve = (id, fn) => {
+        console.log('resolved', id, 'to', fn)
+        ff()
+    }
+
+    ff()
 }
 
 export class MCDioramaElement extends HTMLElement {