Difference between revisions of "GPU/Procedural Texture Generation"
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[[Category:GPU]] | [[Category:GPU]] | ||
| − | The 3DS GPU supports procedural generation of texture data using [[ | + | The 3DS GPU supports procedural generation of texture data using [[GPU/Internal_Registers#GPUREG_TEXUNIT3_PROCTEX0|texture unit 3]]. Little is known about this feature, albeit a few public hints have been dropped. The contents of this page are solely based on reports on a [http://www.4gamer.net/games/017/G001762/20120822007/ presentation] given by DMP. |
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| + | The related GPU registers can be found starting [[GPU/Internal_Registers#GPUREG_TEXUNIT3_PROCTEX0|here]]. | ||
== Overview == | == Overview == | ||
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* Frequency | * Frequency | ||
* Phase | * Phase | ||
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| + | These parameters are configured starting [[GPU/Internal_Registers#GPUREG_TEXUNIT3_PROCTEX1|here]]. | ||
== Repeat Module == | == Repeat Module == | ||
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== Base Shape == | == Base Shape == | ||
| − | The U’’ and V’’ coordinates are used to generate a scalar value in the range [0;1] from the wrapped coordinates using one of six functions | + | The U’’ and V’’ coordinates are used to generate a scalar value in the range [0;1] from the wrapped coordinates using one of six functions documented [[GPU/Internal_Registers#GPUREG_TEXUNIT3_PROCTEX0|here]]. |
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The output of this function is named "g". | The output of this function is named "g". | ||
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* a triangle function | * a triangle function | ||
| − | The final texel color is determined by using the value of F(g) as an index into a configurable lookup table | + | The final texel color is determined by using the value of F(g) as an index into a configurable [[GPU/Internal_Registers#GPUREG_PROCTEX_LUT|lookup table]]. |
Latest revision as of 09:23, 5 December 2015
The 3DS GPU supports procedural generation of texture data using texture unit 3. Little is known about this feature, albeit a few public hints have been dropped. The contents of this page are solely based on reports on a presentation given by DMP.
The related GPU registers can be found starting here.
Overview[edit]
Procedural texture generation has four stages:
- Noise Module (outputs u′,v′)
- Repeat Module (outputs u′′,v′′)
- Base Shape (also notated as G(u′′,v′′), output g)
- F(g) and Lookup Table
Noise Module[edit]
This stage applies noise on the input coordinates. Little is known about this other than that there are three noise parameters:
- Amplitude
- Frequency
- Phase
These parameters are configured starting here.
Repeat Module[edit]
This stage performs basic texture coordinate wrapping on the noised coordinates. It supports symmetric and mirrored wrapping. They don't seem to be configurable beyond that.
Base Shape[edit]
The U’’ and V’’ coordinates are used to generate a scalar value in the range [0;1] from the wrapped coordinates using one of six functions documented here.
The output of this function is named "g".
F(g) and Lookup Table[edit]
F is a selectable function which transforms g to another scalar value. There are two known options for F:
- the identity function
- a triangle function
The final texel color is determined by using the value of F(g) as an index into a configurable lookup table.