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• By elect
Hi,
ok, so, we are having problems with our current mirror reflection implementation.
At the moment we are doing it very simple, so for the i-th frame, we calculate the reflection vectors given the viewPoint and some predefined points on the mirror surface (position and normal).
Then, using the least squared algorithm, we find the point that has the minimum distance from all these reflections vectors. This is going to be our virtual viewPoint (with the right orientation).
After that, we render offscreen to a texture by setting the OpenGL camera on the virtual viewPoint.
And finally we use the rendered texture on the mirror surface.
So far this has always been fine, but now we are having some more strong constraints on accuracy.
What are our best options given that:
- we have a dynamic scene, the mirror and parts of the scene can change continuously from frame to frame
- we have about 3k points (with normals) per mirror, calculated offline using some cad program (such as Catia)
- all the mirror are always perfectly spherical (with different radius vertically and horizontally) and they are always convex
- a scene can have up to 10 mirror
- it should be fast enough also for vr (Htc Vive) on fastest gpus (only desktops)

Looking around, some papers talk about calculating some caustic surface derivation offline, but I don't know if this suits my case
Also, another paper, used some acceleration structures to detect the intersection between the reflection vectors and the scene, and then adjust the corresponding texture coordinate. This looks the most accurate but also very heavy from a computational point of view.

Other than that, I couldn't find anything updated/exhaustive around, can you help me?

• Hello all,
I am currently working on a game engine for use with my game development that I would like to be as flexible as possible.  As such the exact requirements for how things should work can't be nailed down to a specific implementation and I am looking for, at least now, a default good average case scenario design.
Here is what I have implemented:
Deferred rendering using OpenGL Arbitrary number of lights and shadow mapping Each rendered object, as defined by a set of geometry, textures, animation data, and a model matrix is rendered with its own draw call Skeletal animations implemented on the GPU.   Model matrix transformation implemented on the GPU Frustum and octree culling for optimization Here are my questions and concerns:
Doing the skeletal animation on the GPU, currently, requires doing the skinning for each object multiple times per frame: once for the initial geometry rendering and once for the shadow map rendering for each light for which it is not culled.  This seems very inefficient.  Is there a way to do skeletal animation on the GPU only once across these render calls? Without doing the model matrix transformation on the CPU, I fail to see how I can easily batch objects with the same textures and shaders in a single draw call without passing a ton of matrix data to the GPU (an array of model matrices then an index for each vertex into that array for transformation purposes?) If I do the matrix transformations on the CPU, It seems I can't really do the skinning on the GPU as the pre-transformed vertexes will wreck havoc with the calculations, so this seems not viable unless I am missing something Overall it seems like simplest solution is to just do all of the vertex manipulation on the CPU and pass the pre-transformed data to the GPU, using vertex shaders that do basically nothing.  This doesn't seem the most efficient use of the graphics hardware, but could potentially reduce the number of draw calls needed.

Really, I am looking for some advice on how to proceed with this, how something like this is typically handled.  Are the multiple draw calls and skinning calculations not a huge deal?  I would LIKE to save as much of the CPU's time per frame so it can be tasked with other things, as to keep CPU resources open to the implementation of the engine.  However, that becomes a moot point if the GPU becomes a bottleneck.

• Hello!
I would like to introduce Diligent Engine, a project that I've been recently working on. Diligent Engine is a light-weight cross-platform abstraction layer between the application and the platform-specific graphics API. Its main goal is to take advantages of the next-generation APIs such as Direct3D12 and Vulkan, but at the same time provide support for older platforms via Direct3D11, OpenGL and OpenGLES. Diligent Engine exposes common front-end for all supported platforms and provides interoperability with underlying native API. Shader source code converter allows shaders authored in HLSL to be translated to GLSL and used on all platforms. Diligent Engine supports integration with Unity and is designed to be used as a graphics subsystem in a standalone game engine, Unity native plugin or any other 3D application. It is distributed under Apache 2.0 license and is free to use. Full source code is available for download on GitHub.
Features:
True cross-platform Exact same client code for all supported platforms and rendering backends No #if defined(_WIN32) ... #elif defined(LINUX) ... #elif defined(ANDROID) ... No #if defined(D3D11) ... #elif defined(D3D12) ... #elif defined(OPENGL) ... Exact same HLSL shaders run on all platforms and all backends Modular design Components are clearly separated logically and physically and can be used as needed Only take what you need for your project (do not want to keep samples and tutorials in your codebase? Simply remove Samples submodule. Only need core functionality? Use only Core submodule) No 15000 lines-of-code files Clear object-based interface No global states Key graphics features: Automatic shader resource binding designed to leverage the next-generation rendering APIs Multithreaded command buffer generation 50,000 draw calls at 300 fps with D3D12 backend Descriptor, memory and resource state management Modern c++ features to make code fast and reliable The following platforms and low-level APIs are currently supported:
Windows Desktop: Direct3D11, Direct3D12, OpenGL Universal Windows: Direct3D11, Direct3D12 Linux: OpenGL Android: OpenGLES MacOS: OpenGL iOS: OpenGLES API Basics
Initialization
The engine can perform initialization of the API or attach to already existing D3D11/D3D12 device or OpenGL/GLES context. For instance, the following code shows how the engine can be initialized in D3D12 mode:
#include "RenderDeviceFactoryD3D12.h" using namespace Diligent; // ...  GetEngineFactoryD3D12Type GetEngineFactoryD3D12 = nullptr; // Load the dll and import GetEngineFactoryD3D12() function LoadGraphicsEngineD3D12(GetEngineFactoryD3D12); auto *pFactoryD3D11 = GetEngineFactoryD3D12(); EngineD3D12Attribs EngD3D12Attribs; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[0] = 1024; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[1] = 32; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[2] = 16; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[3] = 16; EngD3D12Attribs.NumCommandsToFlushCmdList = 64; RefCntAutoPtr<IRenderDevice> pRenderDevice; RefCntAutoPtr<IDeviceContext> pImmediateContext; SwapChainDesc SwapChainDesc; RefCntAutoPtr<ISwapChain> pSwapChain; pFactoryD3D11->CreateDeviceAndContextsD3D12( EngD3D12Attribs, &pRenderDevice, &pImmediateContext, 0 ); pFactoryD3D11->CreateSwapChainD3D12( pRenderDevice, pImmediateContext, SwapChainDesc, hWnd, &pSwapChain ); Creating Resources
Device resources are created by the render device. The two main resource types are buffers, which represent linear memory, and textures, which use memory layouts optimized for fast filtering. To create a buffer, you need to populate BufferDesc structure and call IRenderDevice::CreateBuffer(). The following code creates a uniform (constant) buffer:
BufferDesc BuffDesc; BufferDesc.Name = "Uniform buffer"; BuffDesc.BindFlags = BIND_UNIFORM_BUFFER; BuffDesc.Usage = USAGE_DYNAMIC; BuffDesc.uiSizeInBytes = sizeof(ShaderConstants); BuffDesc.CPUAccessFlags = CPU_ACCESS_WRITE; m_pDevice->CreateBuffer( BuffDesc, BufferData(), &m_pConstantBuffer ); Similar, to create a texture, populate TextureDesc structure and call IRenderDevice::CreateTexture() as in the following example:
TextureDesc TexDesc; TexDesc.Name = "My texture 2D"; TexDesc.Type = TEXTURE_TYPE_2D; TexDesc.Width = 1024; TexDesc.Height = 1024; TexDesc.Format = TEX_FORMAT_RGBA8_UNORM; TexDesc.Usage = USAGE_DEFAULT; TexDesc.BindFlags = BIND_SHADER_RESOURCE | BIND_RENDER_TARGET | BIND_UNORDERED_ACCESS; TexDesc.Name = "Sample 2D Texture"; m_pRenderDevice->CreateTexture( TexDesc, TextureData(), &m_pTestTex ); Initializing Pipeline State
Diligent Engine follows Direct3D12 style to configure the graphics/compute pipeline. One big Pipelines State Object (PSO) encompasses all required states (all shader stages, input layout description, depth stencil, rasterizer and blend state descriptions etc.)
To create a shader, populate ShaderCreationAttribs structure. An important member is ShaderCreationAttribs::SourceLanguage. The following are valid values for this member:
SHADER_SOURCE_LANGUAGE_DEFAULT  - The shader source format matches the underlying graphics API: HLSL for D3D11 or D3D12 mode, and GLSL for OpenGL and OpenGLES modes. SHADER_SOURCE_LANGUAGE_HLSL  - The shader source is in HLSL. For OpenGL and OpenGLES modes, the source code will be converted to GLSL. See shader converter for details. SHADER_SOURCE_LANGUAGE_GLSL  - The shader source is in GLSL. There is currently no GLSL to HLSL converter. To allow grouping of resources based on the frequency of expected change, Diligent Engine introduces classification of shader variables:
Static variables (SHADER_VARIABLE_TYPE_STATIC) are variables that are expected to be set only once. They may not be changed once a resource is bound to the variable. Such variables are intended to hold global constants such as camera attributes or global light attributes constant buffers. Mutable variables (SHADER_VARIABLE_TYPE_MUTABLE) define resources that are expected to change on a per-material frequency. Examples may include diffuse textures, normal maps etc. Dynamic variables (SHADER_VARIABLE_TYPE_DYNAMIC) are expected to change frequently and randomly. This post describes the resource binding model in Diligent Engine.
The following is an example of shader initialization:
To create a pipeline state object, define instance of PipelineStateDesc structure. The structure defines the pipeline specifics such as if the pipeline is a compute pipeline, number and format of render targets as well as depth-stencil format:
// This is a graphics pipeline PSODesc.IsComputePipeline = false; PSODesc.GraphicsPipeline.NumRenderTargets = 1; PSODesc.GraphicsPipeline.RTVFormats[0] = TEX_FORMAT_RGBA8_UNORM_SRGB; PSODesc.GraphicsPipeline.DSVFormat = TEX_FORMAT_D32_FLOAT; The structure also defines depth-stencil, rasterizer, blend state, input layout and other parameters. For instance, rasterizer state can be defined as in the code snippet below:
// Init rasterizer state RasterizerStateDesc &RasterizerDesc = PSODesc.GraphicsPipeline.RasterizerDesc; RasterizerDesc.FillMode = FILL_MODE_SOLID; RasterizerDesc.CullMode = CULL_MODE_NONE; RasterizerDesc.FrontCounterClockwise = True; RasterizerDesc.ScissorEnable = True; //RSDesc.MultisampleEnable = false; // do not allow msaa (fonts would be degraded) RasterizerDesc.AntialiasedLineEnable = False; When all fields are populated, call IRenderDevice::CreatePipelineState() to create the PSO:
Shader resource binding in Diligent Engine is based on grouping variables in 3 different groups (static, mutable and dynamic). Static variables are variables that are expected to be set only once. They may not be changed once a resource is bound to the variable. Such variables are intended to hold global constants such as camera attributes or global light attributes constant buffers. They are bound directly to the shader object:

m_pPSO->CreateShaderResourceBinding(&m_pSRB); Dynamic and mutable resources are then bound through SRB object:
m_pSRB->GetVariable(SHADER_TYPE_VERTEX, "tex2DDiffuse")->Set(pDiffuseTexSRV); m_pSRB->GetVariable(SHADER_TYPE_VERTEX, "cbRandomAttribs")->Set(pRandomAttrsCB); The difference between mutable and dynamic resources is that mutable ones can only be set once for every instance of a shader resource binding. Dynamic resources can be set multiple times. It is important to properly set the variable type as this may affect performance. Static variables are generally most efficient, followed by mutable. Dynamic variables are most expensive from performance point of view. This post explains shader resource binding in more details.
Setting the Pipeline State and Invoking Draw Command
Before any draw command can be invoked, all required vertex and index buffers as well as the pipeline state should be bound to the device context:
// Clear render target const float zero[4] = {0, 0, 0, 0}; m_pContext->ClearRenderTarget(nullptr, zero); // Set vertex and index buffers IBuffer *buffer[] = {m_pVertexBuffer}; Uint32 offsets[] = {0}; Uint32 strides[] = {sizeof(MyVertex)}; m_pContext->SetVertexBuffers(0, 1, buffer, strides, offsets, SET_VERTEX_BUFFERS_FLAG_RESET); m_pContext->SetIndexBuffer(m_pIndexBuffer, 0); m_pContext->SetPipelineState(m_pPSO); Also, all shader resources must be committed to the device context:
m_pContext->CommitShaderResources(m_pSRB, COMMIT_SHADER_RESOURCES_FLAG_TRANSITION_RESOURCES); When all required states and resources are bound, IDeviceContext::Draw() can be used to execute draw command or IDeviceContext::DispatchCompute() can be used to execute compute command. Note that for a draw command, graphics pipeline must be bound, and for dispatch command, compute pipeline must be bound. Draw() takes DrawAttribs structure as an argument. The structure members define all attributes required to perform the command (primitive topology, number of vertices or indices, if draw call is indexed or not, if draw call is instanced or not, if draw call is indirect or not, etc.). For example:
DrawAttribs attrs; attrs.IsIndexed = true; attrs.IndexType = VT_UINT16; attrs.NumIndices = 36; attrs.Topology = PRIMITIVE_TOPOLOGY_TRIANGLE_LIST; pContext->Draw(attrs); Tutorials and Samples
The GitHub repository contains a number of tutorials and sample applications that demonstrate the API usage.

AntTweakBar sample demonstrates how to use AntTweakBar library to create simple user interface.

Atmospheric scattering sample is a more advanced example. It demonstrates how Diligent Engine can be used to implement various rendering tasks: loading textures from files, using complex shaders, rendering to textures, using compute shaders and unordered access views, etc.

The repository includes Asteroids performance benchmark based on this demo developed by Intel. It renders 50,000 unique textured asteroids and lets compare performance of D3D11 and D3D12 implementations. Every asteroid is a combination of one of 1000 unique meshes and one of 10 unique textures.

Integration with Unity
Diligent Engine supports integration with Unity through Unity low-level native plugin interface. The engine relies on Native API Interoperability to attach to the graphics API initialized by Unity. After Diligent Engine device and context are created, they can be used us usual to create resources and issue rendering commands. GhostCubePlugin shows an example how Diligent Engine can be used to render a ghost cube only visible as a reflection in a mirror.

• By Yxjmir
I'm trying to load data from a .gltf file into a struct to use to load a .bin file. I don't think there is a problem with how the vertex positions are loaded, but with the indices. This is what I get when drawing with glDrawArrays(GL_LINES, ...):

Also, using glDrawElements gives a similar result. Since it looks like its drawing triangles using the wrong vertices for each face, I'm assuming it needs an index buffer/element buffer. (I'm not sure why there is a line going through part of it, it doesn't look like it belongs to a side, re-exported it without texture coordinates checked, and its not there)
I'm using jsoncpp to load the GLTF file, its format is based on JSON. Here is the gltf struct I'm using, and how I parse the file:
glBindVertexArray(g_pGame->m_VAO);
glDrawElements(GL_LINES, g_pGame->m_indices.size(), GL_UNSIGNED_BYTE, (void*)0); // Only shows with GL_UNSIGNED_BYTE
glDrawArrays(GL_LINES, 0, g_pGame->m_vertexCount);
So, I'm asking what type should I use for the indices? it doesn't seem to be unsigned short, which is what I selected with the Khronos Group Exporter for blender. Also, am I reading part or all of the .bin file wrong?
Test.gltf
Test.bin

• That means how do I use base DirectX or OpenGL api's to make a physics based destruction simulation?
Will it be just smart rendering or something else is required?

# OpenGL My VBO world system. Any thoughts?

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In my World structure there are several "chunks" that represent a group of vertices and various vertex attributes, there are three main functions in each chunk: allocate() generates VBOs, upload() sends data to the video card and draw() which obviously draws the chunk, there are also two other functions start3D() and end3D() which sandwich a group of Chunk::draw() calls. I know my structure is pretty solid and it works well. What I'm wondering about is whether my actual OpenGL calls are set up in the best way to maximize performance because gDebugger flagged a bunch of redundant state changes in my draw function and I know that's bad for performance. Anyone know how I could remove redundant state changes and maximize performance assuming I'm targeting GL 2.1

My code is below:

 void start3D() { glEnableClientState(GL_TEXTURE_COORD_ARRAY); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_NORMAL_ARRAY); glEnableVertexAttribArray(attribPointer); } void end3D() { glDisableClientState(GL_TEXTURE_COORD_ARRAY); glDisableClientState(GL_VERTEX_ARRAY); glDisableClientState(GL_NORMAL_ARRAY); glDisableVertexAttribArray(attribPointer); glBindBuffer(GL_ARRAY_BUFFER, 0); } 

 void Chunk::allocate() { glGenBuffers(1, &vBuffer); //positions glBindBuffer(GL_ARRAY_BUFFER, vBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(float), NULL, GL_STATIC_DRAW); glGenBuffers(1, &tBuffer); //texcoords glBindBuffer(GL_ARRAY_BUFFER, tBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(float), NULL, GL_STATIC_DRAW); glGenBuffers(1, &nBuffer); //normals glBindBuffer(GL_ARRAY_BUFFER, nBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(float), NULL, GL_STATIC_DRAW); glGenBuffers(1, &tanBuffer); //tangents glBindBuffer(GL_ARRAY_BUFFER, tanBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(float), NULL, GL_STATIC_DRAW); } 

 void Chunk::upload() { glBindBuffer(GL_ARRAY_BUFFER, tBuffer); //texcoords glBufferData(GL_ARRAY_BUFFER, numtriangles * 6 * sizeof(float), texcoords, GL_STATIC_DRAW); glTexCoordPointer(2, GL_FLOAT, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, vBuffer); //positions glBufferData(GL_ARRAY_BUFFER, numtriangles * 9 * sizeof(float), vertices, GL_STATIC_DRAW); glVertexPointer(3, GL_FLOAT, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, nBuffer); //normals glBufferData(GL_ARRAY_BUFFER, numtriangles * 9 * sizeof(float), normals, GL_STATIC_DRAW); glNormalPointer(GL_FLOAT, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, tanBuffer); //tangents glBufferData(GL_ARRAY_BUFFER, numtriangles * 12 * sizeof(float), tangents, GL_STATIC_DRAW); glVertexAttribPointer(attribPointer, 4, GL_FLOAT, false, 0, 0); } 

 void Chunk::draw() { glActiveTexture(GL_TEXTURE0); glUniform1i(texture_location, 0); glBindTexture(GL_TEXTURE_2D, bitmap); glActiveTexture(GL_TEXTURE1); glUniform1i(normal_texture_location, 1); glBindTexture(GL_TEXTURE_2D, normap); glActiveTexture(GL_TEXTURE2); glUniform1i(height_texture_loc, 2); glBindTexture(GL_TEXTURE_2D, heightmap); glBindBuffer(GL_ARRAY_BUFFER, tBuffer); //texcoords glTexCoordPointer(2, GL_FLOAT, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, vBuffer); //positions glVertexPointer(3, GL_FLOAT, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, nBuffer); //normals glNormalPointer(GL_FLOAT, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, tanBuffer); //tangents glVertexAttribPointer(attribPointer, 4, GL_FLOAT, false, 0, 0); glDrawArrays(GL_TRIANGLES, 0, numtriangles*3); } 

Sample Usage:

 chunk1.allocate(); chunk2.allocate(); chunk3.allocate(); start3D(); chunk1.upload(); chunk2.upload(); chunk3.upload(); end3D(); while(running) { start3D(); chunk1.draw(); chunk2.draw(); chunk3.draw(); end3D(); //do other stuff } 

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Why do you have allocate and upload as two separate functions if they are supposed to be called together? Are there times where you expect to allocate the buffers but not upload any data?

What is the purpose of allocating empty buffers the size of a single float in the allocate function? If you actually indent to pre-allocate the whole buffer, you should allocate a buffer large enough to store the actual data you put into it later and then use glBufferSubData instead to upload the content to an existing buffer; glBufferData will discard the old buffer and create a new one and your pre-allocated buffer was of no use.

You set the vertex attribute pointers in both the upload and the draw functions. Setting the pointers in the upload function serves no purpose since you're not using the binding points anywhere except in the draw function, and the draw function already set the attribute pointers.

You don't have to enable the buffers to upload data to them. Your calls to start3D and stop3D around the upload calls have no purpose.

I find your setup very limiting because you have generic functions to enable vertex attribute arrays, but they force a specific vertex array layout: any vertex array you draw must have a position, a normal, a texture coordinate and a generic attribute array; no more, no less. Either you intend to use that function for the Chunk class only, in which case it is named way too generically named, or you should use a more flexible vertex array system that doesn't force a specific vertex attribute set, but rather enables what is in use. If you intend to only use the functions for the Chunk class, then put the two helper functions in the chunk class to show that they are for the Chunk class specifically and nothing else.

The redundant state changes I can see are, except for setting the attribute pointers in the upload function, could be the result of the very limited test bed you have in the while loop. The while loop calls end3D and then calls start3D again in the next iteration. Unless "// do other stuff" actually depends on end3D being called, the observable state changes in OpenGL could be that you disable and then re-enable some states immediately after each other.

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the bit at the end is just a sample usage not necessarily the best one. And as for start3D and end3D being restrictive I found that in my game it resulted in less opengl calls if I enabled everything right off the bat and then disabled the ones that I did in the rare case that I didn't need all of them not need for example I have a drawSkybox function which disables tangents and normals. As for my draw function do you propose that It looks like this, removing the pointers:
 void Chunk::draw() { glActiveTexture(GL_TEXTURE0); glUniform1i(texture_location, 0); glBindTexture(GL_TEXTURE_2D, bitmap); glActiveTexture(GL_TEXTURE1); glUniform1i(normal_texture_location, 1); glBindTexture(GL_TEXTURE_2D, normap); glActiveTexture(GL_TEXTURE2); glUniform1i(height_texture_loc, 2); glBindTexture(GL_TEXTURE_2D, heightmap); glBindBuffer(GL_ARRAY_BUFFER, tBuffer); //texcoords glBindBuffer(GL_ARRAY_BUFFER, vBuffer); //positions glBindBuffer(GL_ARRAY_BUFFER, nBuffer); //normals glBindBuffer(GL_ARRAY_BUFFER, tanBuffer); //tangents glDrawArrays(GL_TRIANGLES, 0, numtriangles*3); } 

because I tried that and it broke the function.

BTW this code is just for the internals of my game not for a library or anything I don't really care if it makes sense but rather that it's as fast as possible.

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that draw function isn't going to work well, because you are binding 4 VBOs in a row, which means that only the last one is bound before drawing
you are drawing tangents
you should have kept the "pointers" to the data, and even better if you want fast rendering - interleave the data in a single VBO using a struct
http://www.opengl.org/wiki/Vertex_Specification_Best_Practices

unfortunately i have to cut my reply short, i have an exam to go to =)

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the bit at the end is just a sample usage not necessarily the best one. And as for start3D and end3D being restrictive I found that in my game it resulted in less opengl calls if I enabled everything right off the bat and then disabled the ones that I did in the rare case that I didn't need all of them not need for example I have a drawSkybox function which disables tangents and normals.

It may work now, but it will definitely bite you later on because it's going to be a nightmare to maintain and get right, and especially get optimal as you aim for. You may very well get to the point where the disabling-and-enabling-when-done approach will cost you just as much as enabling-and-disabling-when-done approach. What you effectively end up with is a global enable state, and then local disable-on-demand calls.

You're aiming for a global optimum, so you're gonna need a global solution. For example, some state manager that doesn't re-enable things that are enabled already, or sets pointers that are already set. You can only achieve local optimum with local calls. For example, consider that you draw your sky box that, as you say, doesn't have tangents and normals, so you disable tangents and normals before drawing it, and then re-enable it again. That may be the optimum way to handle it since you only need to disable a few states.

Then you want to draw a small GUI or something that doesn't have tangents and normals either. So you do the same thing again; you disable them, draw the GUI and enable them before exiting; again, locally the optimum way to do it. But the net effect are four redundant calls; two do enabble two states and then two more to disable them again. Local optimum, but not global optimum.

As for my draw function do you propose that It looks like this, removing the pointers:
 void Chunk::draw() { glActiveTexture(GL_TEXTURE0); glUniform1i(texture_location, 0); glBindTexture(GL_TEXTURE_2D, bitmap); glActiveTexture(GL_TEXTURE1); glUniform1i(normal_texture_location, 1); glBindTexture(GL_TEXTURE_2D, normap); glActiveTexture(GL_TEXTURE2); glUniform1i(height_texture_loc, 2); glBindTexture(GL_TEXTURE_2D, heightmap); glBindBuffer(GL_ARRAY_BUFFER, tBuffer); //texcoords glBindBuffer(GL_ARRAY_BUFFER, vBuffer); //positions glBindBuffer(GL_ARRAY_BUFFER, nBuffer); //normals glBindBuffer(GL_ARRAY_BUFFER, tanBuffer); //tangents glDrawArrays(GL_TRIANGLES, 0, numtriangles*3); } 

because I tried that and it broke the function.

Kaptein already addressed it, but I said that the pointers in the update function, not the draw function, served no purpose.

BTW this code is just for the internals of my game not for a library or anything I don't really care if it makes sense but rather that it's as fast as possible.

When your code base grows, you will forget about the details about an increasing amount of your very own code, and it will become unfamiliar to you. Design is not only for other's sake, but for your own as well.

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So I put all my arrays into one and here is the resulting code:

 void Chunk::upload() { glBindBuffer(GL_ARRAY_BUFFER, vBuffer); glBufferData(GL_ARRAY_BUFFER, totalsize * sizeof(float), vertices, GL_STATIC_DRAW); } 

 void Chunk::draw() { glActiveTexture(GL_TEXTURE0); glUniform1i(texture_location, 0); glBindTexture(GL_TEXTURE_2D, bitmap); glActiveTexture(GL_TEXTURE1); glUniform1i(normal_texture_location, 1); glBindTexture(GL_TEXTURE_2D, normap); glActiveTexture(GL_TEXTURE2); glUniform1i(height_texture_loc, 2); glBindTexture(GL_TEXTURE_2D, heightmap); glBindBuffer(GL_ARRAY_BUFFER, vBuffer); glVertexPointer(3, GL_FLOAT, 0, BUFFER_OFFSET(v_start * sizeof(float))); glTexCoordPointer(2, GL_FLOAT, 0, BUFFER_OFFSET(t_start * sizeof(float))); glNormalPointer(GL_FLOAT, 0, BUFFER_OFFSET(n_start * sizeof(float))); glVertexAttribPointer(attribPointer, 4, GL_FLOAT, false, 0, BUFFER_OFFSET(tan_start * sizeof(float))); glDrawArrays(GL_TRIANGLES, 0, numtriangles*3); } 

I works fine but the problem is that I thought I could improve performance by moving the part where I set my pointers into the upload function, however for some reason It doesn't work unless I set the pointers every time I draw. Any way I can avoid setting the pointers every draw call considering they never change? Edited by ic0de

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You can use vertex array objects then. They encapsulate binding points into a single object. The problem with the pointers is that they are global (unless you're using VAO that is, in which case the are local to the VAO), so setting them in the upload function won't do any good as soon as you upload a second chunk; the pointers for the first chunk are overwritten. And not to mention that you cannot have anything other vertex array overwriting the pointers either.

Using VAO does not change the fact that you have to bind something for every single chunk every frame. You just get rid of the calls to the pointer-functions, but replace them with a bind-call instead. Edited by Brother Bob

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Using VAO's now but for some reason it isn't working here's my code:

 void Chunk::allocate() { if(GLEW_ARB_vertex_array_object) { glGenVertexArrays(1, &vao); glBindVertexArray(vao); } glGenBuffers(1, &vBuffer); glBindBuffer(GL_ARRAY_BUFFER, vBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(float), NULL, GL_STATIC_DRAW); if(GLEW_ARB_vertex_array_object) { glBindVertexArray(0); } } 

 void Chunk::upload() { if(GLEW_ARB_vertex_array_object) { glBindVertexArray(vao); } glBindBuffer(GL_ARRAY_BUFFER, vBuffer); glBufferData(GL_ARRAY_BUFFER, totalsize * sizeof(float), vertices, GL_STATIC_DRAW); if(GLEW_ARB_vertex_array_object) { glVertexAttribPointer(posAttrib, 3, GL_FLOAT, false, 0, BUFFER_OFFSET(v_start * sizeof(float))); glVertexAttribPointer(texAttrib, 2, GL_FLOAT, false, 0, BUFFER_OFFSET(t_start * sizeof(float))); glVertexAttribPointer(normAttrib, 3, GL_FLOAT, true, 0, BUFFER_OFFSET(n_start * sizeof(float))); glVertexAttribPointer(tanAttrib, 4, GL_FLOAT, false, 0, BUFFER_OFFSET(tan_start * sizeof(float))); glBindVertexArray(0); } glBindBuffer(GL_ARRAY_BUFFER, 0); } 

 void Chunk::draw() { glActiveTexture(GL_TEXTURE0); glUniform1i(texture_location, 0); glBindTexture(GL_TEXTURE_2D, bitmap); glActiveTexture(GL_TEXTURE1); glUniform1i(normal_texture_location, 1); glBindTexture(GL_TEXTURE_2D, normap); glActiveTexture(GL_TEXTURE2); glUniform1i(height_texture_loc, 2); glBindTexture(GL_TEXTURE_2D, heightmap); if(GLEW_ARB_vertex_array_object) { glBindVertexArray(vao); } else { glBindBuffer(GL_ARRAY_BUFFER, vBuffer); glVertexAttribPointer(posAttrib, 3, GL_FLOAT, false, 0, BUFFER_OFFSET(v_start * sizeof(float))); glVertexAttribPointer(texAttrib, 2, GL_FLOAT, false, 0, BUFFER_OFFSET(t_start * sizeof(float))); glVertexAttribPointer(normAttrib, 3, GL_FLOAT, true, 0, BUFFER_OFFSET(n_start * sizeof(float))); glVertexAttribPointer(tanAttrib, 4, GL_FLOAT, false, 0, BUFFER_OFFSET(tan_start * sizeof(float))); } glDrawArrays(GL_TRIANGLES, 0, numtriangles*3); if(GLEW_ARB_vertex_array_object) { glBindVertexArray(0); } } 

I have it set up so that computers that don't support the VAO extension can still render properly seeing as my target is GL 2.1. Now everything works as expected when I force the check to fail but when the check passes is when it doesn't work. Edited by ic0de

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that draw function isn't going to work well, because you are binding 4 VBOs in a row, which means that only the last one is bound before drawing
you are drawing tangents

That is not correct. The calls to glVertexPointer() and friends work on whatever vertex buffer was active at the time of the call. After the call he is free to bind a different vertex buffer and call, for example, glNormalPointer().

However his code will leave trash bound when other objects are drawn that don’t have all of the same attributes because they are never unbound.

ic0de, you need to call glActiveTexture() before binding textures to different slots (calling glBindTexture()).
Additionally you seem to have switched to shaders but I don’t see any shaders ever being set. This has to be done before setting uniforms etc.

L. Spiro Edited by L. Spiro

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Additionally you seem to have switched to shaders but I don’t see any shaders ever being set. This has to be done before setting uniforms etc.

There's allot of work being done outside the scope of this code that I posted shading is one of them, I was mainly concerned about my VBO's and that's why I didn't post the other code.