40 lines
1.3 KiB
Markdown
40 lines
1.3 KiB
Markdown
# Chapter 13: Instancing & Procedural Generation
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As I read this book, I summarize what I think is wrong. If you think my comments are wrong then please let me know. We can dicuss more and update your opinion.
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## Morphing
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Morphing which is explaned by this book isn't the cannonical way of morphing. Morphing is usually a morphable mesh where primitives’ attributes are obtained by adding the original attributes to a weighted sum of targets attributes.
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For instance, the the position of vertices for the primitive at index i are computed in this way:
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```
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primitives[i].attributes.POSITION +
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weights[0] * primitives[i].targets[0].POSITION +
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weights[1] * primitives[i].targets[1].POSITION +
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weights[2] * primitives[i].targets[2].POSITION + ...
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```
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Apple's animoji is the most famous example of morphing.
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## Miscalculation of the world position
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In Nature.metal and Houses.metal, the world position is calculated incorrectly, replace:
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```
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out.worldPosition = (uniforms.modelMatrix * vertexIn.position
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* instance.modelMatrix).xyz;
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```
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With:
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```
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out.worldPosition = (uniforms.modelMatrix * instance.modelMatrix
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* vertexIn.position).xyz;
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```
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The result isn't changed because the world position is not used anywhere. |